AP BIO EXAM

Metapopulation

A number of linked, local populations

Style

Leads from the stigma to the ovary

Gonads

Organs that produce gametes

Integration of sensory information

Processing of sensory information.

Attached earlobes

Recessive

Presynaptic cell

The transmitting neuron

Is water a good solvent?

Water is an excellent but limited solvent.

What is the sequence of telomerase?

AAUCCC

Production Efficiency

the percentage of energy stored in assimilated food that is NOT used for respiration.

Methyl group

(-CH₃); Methylate compound; Affects the expression of genes when on DNA or on proteins bound to DNA. Affects the shape and function of male and female sex hormones. Not reactive, but often serves as a recognizable tag on biological molecules. Example: 5-Methyl Cytosine

Resource Partitioning

The differentiation of niches that enables similar species to coexist in a community.

What is the specific heat of water?

1 cal/g • °C

Map units

1% recombination frequency

How strong are hydrogen bonds compared to covalent bonds?

1/20 the strength

Bond energy of polar covalent bond?

100 kilo cal/mol

Biological Clock

24 hour cycle normally coordinated with the cycle of light and darkness. Maintains circadian rhythm.

XYY in males?

Taller

Hypothalamus

The Brain region that controls the circadian clock and has the sensors for thermoregulation.

Template strand

The DNA strand that provides the pattern, or template, for ordering, by complimentary base pairing, the sequence of nucleotides in an RNA transcript.

Residual volume

The air that remains after a forced exhalation.

Breathing

The alternating inhalation and exhalation of air

Rhizomes

The base of an iris plant is an example of a rhizome, a horizontal shoot that grows just below the surface. Vertical shoots emerge from axillary buds on the rhizome.

Where do parasympathetic nerves exit the CNS?

The base of the brain or spinal cord and form synapses in ganglia near or within an internal organ.

Reflexes

The body's automatic responses to certain stimuli

Benthic Zone

The bottom surface of an aquatic environment.

Vasa recta

The capillary system in the kidney that serves the loop of Henle

Ecosystem

The community of organisms in an area and the physical factors with which those organisms interact.

Cellulase

The enzyme that breaks down cellulose.

Molarity

The number of moles of solute per liter of solution.

What determines the unique characteristics of a particular amino acid?

The physical and chemical properties of the side chain.

Describe the function of lacI.

The regulatory gene, lacI, located outside the lac operon, codes for an allosteric repressor protein that can switch off the lac operon by binding to the operator. The lac repressor is active by itself, binding to the operator and switching the lac operon off. In this case, a small specific molecule, an inducer, allolactose, inactivates the repressor. Without the repressor bound, the lac operon is transcribed into mRNA for the lactose-utilizing enzymes.

Monomer

The repeating units that serve as the building blocks of a polymer

Pulse

The rhythmic bulging of the artery walls.

Ingroup

The species being studied.

Development

The specific series of changes by which cells form tissues, organs, and organisms.

Homeostasis

The stead-state physiological condition of the body

Internodes

The stem segments between nodes.

Metabolic Rate

The sum of all the energy an animal uses in a given time

Ecosystem

The sum of all the organisms living in a given area and the abiotic factors with which they interact.

Character displacement

The tendency for characteristics to diverge more in sympatric than in allopatric populations of two species.

Assisted Migration

The translocation of a species to a favorable habitat beyond its native range to protect the species from human-caused threats.

Nephrons

The tubular excretory unit of the vertebrate kidney

Excitement phase

Vasocongestion. Vagina becomes lubricated, myotonia may occur.

Glomerulus

A ball of capillaries surrounded by Bowman's Capsule in the nephron and serving as the site of filtration in the vertebrate kidney

Dihybrid cross

A cross between f1 dihybrids

Bowman's Capsule

A cup-shaped receptacle in the vertebrate kidney that is the initial, expanded segment of the nephron, where filtrate enters from the blood.

Macrophages

A phagocytic cell present in many tissues that functions in innate immunity by destroying microbes and in acquired immunity as an antigen presenting cell.

Polypeptide

A polymer of amino acids.

Pyrimidine

A type of nitrogenous base with a 6-membered ring of carbon and nitrogen atoms. Contains cytosine (C), thymine (T), and uracil (U, only in RNA).

Genetically Unlinked

Alleles of such genes assort independently, as if they were on different chromosomes

Shared derived character

An evolutionary novelty unique to a clade.

Basal Surface

Anchors the cells to a basement membrane or basal lamina made of extracellular matrix

How are T/B cells specific?

Because all antigen receptors produced by a single cell are identical, they bind to the same epitope. Each B or T cell thus displays specificity for a particular epitope, enabling it respond to any pathogen that produces molecules containing that epitope.

Polyploidy

Cell division that results in extra sets of chromosomes, creating a new species.

Genetic Drift

Chance events that cause allele frequencies to fluctuate unpredictably from one generation to the next, especially in small populations.

∆N var.

Change in population size

Analogy

Convergent evolution of similar adaptations because natural selection in similar environments rather than from shared ancestry

Hormonal proteins

Coordination of an organism's activities; Inulin causes tissues to take up glucose to regulate blood sugar concentration.

Dll gene

Distal-less gene; "master regulatory" gene for limb formation

Derivatives

Divide until the cells they produce become specialized in mature tissues.

Polydatyly

Dominant allele that causes 6-digits per appendage. Results in < 1/400 babies having 6 fingers.

Type III Survivorship Curve

Drops sharply at the start, reflecting very high death rates for the young, but flattens out as death rates decline for those few individuals that survive the early period of die-off (Ass. with org. that produce lots of offspring ie. oyster)

Biomass pyramid

Each tier represents the standing crop in one trophic level. Most biomass pyramids narrow sharply from primary producers at the base to top level carnivores at the apex because energy transfers between trophic levels are so inefficient.

Sustainable development

Economic development that meets the needs of people today without limiting the ability of future generations to meet their needs.

Define and list the basic amino acids.

Have amino groups in their side chains that are generally positive in charge. Lysine, Arginine, Histidine. Hydrophilic.

Homologous chromosomes

Have the same size, shape, banding patterns, and the same type of gene at each locus up and down the chromosome.

Habituation

Learning to ignore stimuli that don't change and have no importance

Perennials

Live many years, and include trees, shrubs, and some grasses.

Capillaries

Microscopic vessels with very thin, porous walls.

Sexual Reproduction in Fungi

Mycelium > Plasmogamy > Karyogamy > Meiosis > Spores > Germination

How is the lac operon under dual control?

Negative control by the lac repressor, and positive control by CAP. The state of the lac repressor (with or without bound allolactose) determines whether or not transcription of the lac operon's genes occurs at all; the state of CAP (with our without cAMP), controls the rate of transcription if the operon is repressor-free.

Garrod

One gene, one enzyme

The effect of all stimuli on sensory receptors is to?

Open/close ion channels

Diastole

Relaxation phase of the cardiac cycle.

How much of NPP is available to secondary consumers?

.1*.1 or 1%

joule (J)

.239 cal

How far apart are the bases stacked?

.34 nm apart, meaning there are ten layers of base pairs in each full turn of the helix.

When is water most dense?

4° Celsius

Sex chromosomes

A pair of chromosomes that determine the gender of an animal.

Genotype

An organism's genetic makeup - an individual's allele combination.

Cryptic Coloration

Camouflage

What are the chemicals that make up living organisms based on, mostly?

Carbon

K

Carrying Capacity

Trait

Each variant for a character

Egg

Female gamete

What is found within the extracellular matrix?

Fibroblasts, Macrophages

GnRH

Gonadotropin-releasing Hormone; Secreted by the hypothalamus. Directs the anterior pituitary to secrete the gonadotropins, FSH, and LH.

Describe replication in eukaryotic chromosomes?

Hundreds or even a few thousand replication origins. Multiple replication bubbles form and eventually fuse, thus speeding up the copying of the very long DNA molecules

Immigration

Influx of individuals from a population

Obligate mutualism

Mutualism in which at least one species has lost the ability to survive on its own

Capillary beds

Networks of capillaries

Hydroxide ion

OH-

Starch

Polymer of glucose monomers. Ex. Amylase, maltose

Syndrome

Set of traits

Gene

The discrete unit of inheritance that determines the amino acid sequence of a polypeptide, and consists of DNA.

Emigration

The movement fo individuals out of a population and into other locations

Pelagic Zone

The open water component of aquatic biomes

Stele

The vascular tissue of a root or stem.

What happens when a hydrocarbon undergoes a reaction?

They typically release a lot of energy.

Venules

What capillaries converge into/ branched veins

r

difference between the per capita birth rate and the per capita death rate r = b-m

How much does protein-coding DNA account for the genome?

1.5%

Avg. eco. footprint in US?

10 ha.

TRNA

80 nuke structure with Anticodon complementary to an mRNA codon and the 3'ACC end that binds to the correct AA. Function: To pair the correct Amino Acid with the correct mRNA codon Each different type of AA has its own specific aminoacyl-tRNA synthetase enzyme with an active site that bind only to 1 AA and to the one or more tRNA's with the correct anticodon for that AA. The energy cost for binding the correct AA to the tRNA = 1 ATP

Sensory adaptation

A decrease in responsiveness to a stimuli upon continued stimulation.

Linkage map

A genetic map based on recombination frequencies

Population

A group of individuals of the same species that live in the same area and interbreed, producing fertile offspring.

Stigma

A sticky structure at the tip of the carpel that receives pollen

Secondary Consumers

Carnivores that eat herbivores.

Tertiary Consumers

Carnivores that eat other carnivores.

Autosomes

Chromosomes that have no bearing on gender.

What are the four main classes of large biological molecules found in all living things?

Carbs, lipids, proteins, nucleic acids.

Complex body plans include interstitial + what other fluid?

Circulatory fluid (ie. blood)

Bryophyte sporophytes

Contain plastids that are usually green and photosynthetic when the sporophytes are young. Cannot live independently. Dependent on parental gametophyte for supplies of sugars, AA, minerals, and water. Consists of foot, seta, sporangium. Can generate 50 million spores.

X chromosome

Contains approximately 1100 X-linked genes- many unrelated to sex.

What makes a compound "organic"

Contains carbon

Widows peak

Dominant

Ginkgophyta

Flagellated sperm. Ginkgo biloba is the only surviving species of this phylum. Has deciduous fanlike leaves that turn gold in autumn. Tolerates air pollution well.

Ovule

Megasporangium + Megaspore + Integument(s) Inside each ovule, a female gametophyte develops from a megapsore and produces 1 or more eggs.

Uterine cycle

Menstrual cycle; The process that refers specifically to the changes that occur about once a month in the uterus.

Sporophyte

Multicellular/diploid "spore-producing plant." Produces haploid spores via meiosis.

Gametophyte

Multicellular/haploid "gamete-producing plant" Produces haploid eggs/sperm by mitosis

Root

Organ that anchors a vascular plant in the soil, absorbs minerals and water, and often stores carbohydrates and other reserves

Vascular Plants

Plants that have a complex vascular tissue system Form a clade that comprises about 93% of all extant plant species

Why does some phenotypic variation not result from genetic differences among individuals?

Phenotype is the product of an inherited genotype and many environmental influences. (ex. bodybuilders). Only the genetically determined part of phenotypic variation can have evolutionary consequences.

Nonvascular Plants

Plants without an extensive transport system

Fibrous proteins

Proteins shaped like long fibers.

Fossils

Remains or traces of organisms from the past.

Explain the difference between resource partitioning and character displacement.

Resource partitioning concerns itself with differentiation of niches to avoid competition. Character displacement deals with evolved characteristics as a result of trying to partition the resources. Ex. Downy Woodpecker hunts for small insects on the tips of trunks and thus has a smaller beak and is smaller in general. Hairy woodpecker is larger with a larger beak to rip off more bark and eats larger insects as a result. These populations are sympatric.

Control elements

Segments of noncoding DNA that serve as binding sites for the proteins called transcription factors.

Artificial selection

Selection and breeding of individuals that possess desired traits. As a result, artificial selection, crops, livestock animals, and pets often bear little resemblance to their wild ancestors.

Kin selection

Selection for acts of altruistic behavior that enhance survival of related individuals at some cost to the actor Ex: Jumping in front of a bullet for pregnant wife.

Sieve-tube elements

Sieve-tube members; Chains of cells in the phloem of angiosperms that transport nutrients. Alive, but lack nucleus, ribosomes, a distinct vacuole, and cytoskeletal elements. This reduction in cell contents enables nutrients to pass more easily through the cell.

Describe determination with MyoD

Signals from other cells lead to activation of a master regulatory gene called myoD, and the cell makes MyoD protein, a specific transcription factor that acts as an activator. The cell, now called a myoblast, is irreversible committed to becoming a skeletal muscle cell

List barrier defenses

Skin, mucous membranes lining the digestive, respiratory, urniary, and reproductive tracts. Saliva, tears, and mucous membranes. Washing + hostile environment (lysozyme + acidic environments)

Lenticels

Small, raised areas dotting the periderm in which there is more space between bork cells, enabling living cells within a woody stem or root to exchange gases with the outside air.

Vascular Bundles

Stele of stems and leaves that separate strands containing xylem/phloem.

DNA technology

Techniques for sequencing and manipulating DNA

Monophyletic

Taxon/clade that consist of an ancestral species and all of its descendants

Rings of cellulose-synthesizing proteins

The cells of both land plants and charophytes have distinctive circular rings of proteins in the plasma membrane. These protein rings synthesize the cellulose microfibrils of the cell wall. In contrast, non-charophyte algae have linear sets of proteins that synthesize cellulose.

Alarm Calls

Vervet monkeys learn the correct alarm calls for snake/eagle/leopard. If the wrong call is given, lack of response from adults

Triplet code

The genetic instructions for a polypeptide chain are written in the DNA as a series of non overlapping, three-nucleotide words.

Epitope

The small, accessible portion of an antigen that binds to an antigen receptor

Osmolarity

The unit of measurement for solute concentration. Moles of solute per liter of solution. most/L

Roger Kornberg

Used X-Ray crystallography to determine the 3d structure of RNA polymerase II. Aimed x-ray beam through crystallized RNA, atoms of the crystal diffracted the x-rays into an orderly array that a digital detector recorded as a pattern of spots called an x-ray diffraction pattern.

Why make phylogenetic trees as hypothesis?

Allows us to make and test predictions based on the assumption that a particular phylogeny is correct.

Who consumes most of the ecosystem's production?

Detritivores.

Fast-twitch fibers

Develop tension 2-3x faster than slow twitch. Enable brief, rapid, powerful contractions. More SR. Glycolitic or oxidative, helping hydrolyze ATP.

4.6 million.

How many nucleotide pairs in a single E.coli chromosome?

Heterokaryon

A fused mycelium that contains coexisting, genetically different nuclei. The heterokaryotic condition offers some advantages of diploidy in that one haploid genome may compensate for harmful mutations in the other.

Polyribosome

A group of several ribosomes attached to, and translating, the same messenger RNA molecule.

Tay-Sachs

A human genetic disease caused by a phenotypically recessive allele for a dysfunctional enzyme, leading to accumulation of certain lipids in the brain. Seizures, blindness, and degeneration of motor and mental performance usually become manifest a few months after birth, followed by death within a few years. Heterozygotes individuals phenotypically don't exhibit symptoms.

Genome-wide association studies

A large-scale analysis of the genomes of many people having a certain phenotype or disease, with the aim of finding genetic markers that correlate with that phenotype or disease.

Dopamine

Biogenic amines made from tyrosine released at many sites in the brain and affect sleep, mood, attention, and learning.

Physiology

Biological function

What is the biological significance of evaporative cooling?

Terrestrial animals can lose a lot of heat energy through evaporative cooling while losing only a small amount of water. Also, water is a liquid and not a gas in most habitats on Earth, and evaporative cooling helps moderate temperature changes in lakes and oceans.

What is the biological significance of water being a good solvent?

When dissolved in water, individual molecules and/or ions can collide and react (especially with the assistance of enzymes) at reaction rates that are vastly faster than reaction rates for dry reactants (which would also have no access to enzymes).

Describe the experiments done with dll genes

When dll was activated in animal bodies that weren't arthropods, all sorts of different limbs formed, including chicken legs, fins, the parapodia of marine worms, and the tube feet on sea urchins.

Fungi nutrition

Heterotrophs; Cannot make their own food as plants and algae. Fungi do not ingest their food. Instead, a fungus absorbs nutrients from the environment outside of its body by secreting hydrolytic exoenzymes into their surroundings. These enzymes break down complex molecules to smaller organic compounds that the fungi can absorb into their bodies and use.

Cork cambium

Replaces the epidermis with the ticker tougher periderm.

What is gene expression?

Replication of DNA, when DNA directs RNA synthesis, and when DNA, through RNA, controls protein synthesis.

Spores

Reproductive cells that can develop into a new haploid organisms without fusing with another cell.

Why can't PCR substitute for gene cloning in cells when large amounts of a gene are required?

Occasional errors during PCR replication limit the number of good copies and the length of DNA fragments that can be copied.

How do Hydrogen ions and Hydroxide ions form?

Occasionally, a hydrogen atom participating in a hydrogen bond between two water molecules shifts from one molecule to the other, leaving an electron behind.

Reciprocal altruism

Occurs between unrelated individuals in social groups where long-term relationships are common and high levels of cognition are present for keeping track of other individuals who honor the commitment vs. those who cheat. Ex: Wolf offers food to other wold even tho no kinship. Babboon may help unrelated comp

Disruptive Selection

Occurs when conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes.

Genetic engineering

The direct manipulation of genes for practical purposes.

Hydrolysis

The dismemberment of a polymer into a monomer, when the bond between monomers is broken by the addition of a water molecule, with a hydrogen from water attaching to one molecule and the hydroxyl group attaching to the other. Example: Digestion Bulk of food is polymers too large to enter our cells. Enzymes attack polymers, speeding hydrolysis. Released monomers are then absorb into bloodstream.

Genetic map

Ordered list of the genetic loci along a particular chromosome

Stolons

On strawberry plants, stolons are horizontal shoots that grows along the surface. These "runners" enable a plant to reproduce asexually, as platelets form at nodes along each runner.

Dihybrids

Individuals heterozygous for the two characters being followed in the cross

What is the rate of gas exchange proportional to?

Membrane surface area involved in exchange

Sporophylls

Modified leaves that bear sporangia

Polar molecule

Molecule with an unequal sharing of electrons amongst its atoms.

Correlation between NPP and water?

NPP ++ as annual precipitation ++.

N variable

Population size

Action potential

A massive change in membrane voltage. Has a constant magnitude and can regenerate in adjacent regions of the membrane.

Migration

A regular long-distance change in location.

Reproductive Table

Age specific summary of reproductive rates in a population.

Seed

An embryo packaged with a supply of nutrients inside a protective coat.

Endothermic

Animal is warmed mostly by that generated by metabolism

Age structure

Compilation of all the cohorts in a population

Embryo sac

Female gametophyte found in the ovule during the angiosperm life cycle. Consists of only a few cells, one of which is the ff.

External fertilization

Female releases eggs into the environment, where the male fertilizes them

Leukocytes

Fight infections. Phagocytic. Lymphocytes develop into B and T cells. Found outside the circulatory system, patrolling both interstitial fluid and the lymphatic system.

Foraging

Food obtaining behavior

Tetrapod

Having 4 limbs.

F1 generation

Hybrid offspring of the P generation

Intrasexual selection

Involves competition between members of one sex for mates

Hox gene

Master regulatory gene for pattern formation in animal development. Contains homeobox

CNS

Neurons that carry out integration

Partial pressure

Pressure exerted by a particular gas in a mixture of gases.

Why is MRSA resistant to multiple antibiotics?

Probably because bacteria can exchange genes with members of their own and other species.

Communication

Producing, receiving, and responding to these signals

Abiotic factors

Rocks, soil, mineral availability, water, oxygen content, salinity... + Climate: temperature, water, sunlight, and wind.

Dendrochronology

Science of analyzing tree growth ring patterns

How did scientists clone Dolly?

Semi-starved mammary cells in a culture-medium, arresting the cell cycle and causing dedifferentiation of cells from mammry-cell donor. Removed nucleus from egg cell from ovary of a different donor. Fused dedifferentiated mammary cells with enucleated egg. Grew fertilized egg in culture until the early-embryo stage. Implanted embryo into uterus of a third sheep, where embryonic development took place and Dolly was born, genetically identical to her mammary-cell donor.

Three stages of information processing by a nervous system

Sensory input, integration, and motor output

Secretion

The active transport of wastes and certain other solutes from the body fluid into the filtrate in an excretory system

Adhesion

The clinging of one substance to another.

Frequency-Dependent selection

The fitness of a phenotype depends on how common it is in the population. Ex. scale eating fish

Differentiation

The process by which cells become specialized in structure and function.

Cell differentiation

The process by which cells with the same genes become different from one another.

Lens

Transparent, flexible, layered structure made of very stable lens proteins (derived from heat-shock proteins) that focuses light on the retina. When the muscles of the ciliary body are relaxed, the suspensory ligaments hold the lens under tension, thus it is flat and thin for distance focusing. When ciliary body muscles contract, tension of the suspensory ligaments is relaxed and lens becomes rounder for close focusing.

Why are complimentary strands of DNA important?

When the cell divides, complementary strands allow it to generate two identical copies of each DNA molecule, which are distributed to the daughter cells.

Cambrian Explosion

Many present day animal phyla appear suddenly in fossils formed 535-525 million years ago. Fossils of several animals- sponges and cnidarians- appear in even older rocks. Emergence of predators with claws.

Temperature

Measure of the energy that represents the average kinetic energy of the molecules in a body of matter, regardless of volume.

What is systolic pressure?

Pressure when the heart contracts during ventricular systole.

Translocation (chromosomes

Result of chromosomal breakage; the fragment joins a non homologous chromosome.

Lymph nodes

Small, lymph-filtering organs along a lymph vessel. Inside each node is a honeycomb of connective tissue with spaves filled by WBC'.

Zygote

Diploid cell

Motor system

Efferent component in the PNS that consists of neurons that carry signals to skeletal muscles.

Glia

Help nourish, insulate, and replenish neurons, and in some cases, modulate neuron function. (Myelin Sheath)

Biotic

Living

B

Number of births in the population during the time interval. B=bN during 1 year

Is a taxon = clade?

Only if monophyletic

Erythrocytes

RBC's

Enzymes

Specialized macromolecules that speed up chemical reactions.

Body Plan

The overall 3d arrangement of an organisms

Heat of Vaporization

The quantity of heat a liquid must absorb for 1g of it to be converted from the liquid to the gaseous state.

Hydration shell

The sphere of water molecules around each dissolved ion

Life History

The traits that affect an organism's schedule of reproduction and survival.

∆t

Time interval

Why can't silicon replace carbon as the organic molecule of life?

Too heavy.

Aposematic Coloration

Warning coloration Ex. Poison dart frogs

Color Blindness

X-Linked disorder

How many drosophila genes are there?

14k

How many different amino acids make up proteins?

20 amino acids, linked in unbranched polymers.

Y chromosome

78 genes code for about 25 proteins. About hald of these genes are expressed only in the testis.

Transcription Factor

A regulatory protein that binds to DNA and affects transcription of specific genes.

Peptide bond

Bond between amino acids.

Gymnosperm Phyla

Cycadophyta, Ginkgophyta, Gnetophyta, and Coniferophyta

Desiccation

Extreme dehydration

Why do cleared areas typically experience greater temperature extremes?

Greater solar radiation and wind currents arise from the rapid heating and cooling of open land.

Strobili

Groups of sporophylls in lycophytes and gymnosperms that form con-like structures.

Hydrogen ion

H+

Seed plants

Heterosporous.

Microglia

Immune cells in the CNS that protect against pathogens

Stimulus

In feedback regulation, a fluctuation in a variable that triggers a response.

Uniform Dispersion

Individuals are evenly spaced (nesting seabirds on a rocky island)

DNA ligase

Joins Okazaki fragments of lagging strand; on leading strand, joins 3' end of DNA that replaces primer to rest of leading strand DNA

Steroids

Lipids characterized by a carbon skeleton consisting of four fused rings. Different steroids are distinguished by the particular chemical groups attached to the ensemble of rings.

Ectomycorrhizal Fungi

Mycorrhizal fungi that forms sheaths of hyphae over the surface of a root and typically grows into the extracellular spaces of the root cortex.

Ribozymes

RNA mlcs that function as enzymes; The intron RNA functions as a ribozyme and catalyzes its own excision.

Gene

Sequence of DNA that codes for a polypeptide/protein or an RNA

When does speciation begin?

Speciation begins only after gene flow between populations is interrupted, perhaps by changing environmental conditions or by unpredictable events, such as a storm that transports a few individuals to a new area.

Sensory reception

The detection of a stimulus by sensory cells. Some sensory cells are themselves specialized neurons, others are non-neuronal cells that regulate neurons.

Hybridization

The mating, or crossing, or two true-breeding varieties.

D

number of deaths in the population during the time interval D = mN

Foundation species

"Ecosystem Engineers" Species that dramatically alter their environment. The effects can be positive or negative, depending on the needs of the other species. Ex. Beaver.

Gymnosperms

"Naked seeds" - Vascular plants whose seeds are not enclosed in chambers. Forms a clade. Includes conifers.

Carboxyl group

(-COOH); Carboxylic acid, or organic acid; Acts as an acid (donates H+) because the covalent bond between oxygen and hydrogen is so polar. Example: Acetic acid.

Prod. Eff. of Birds/Mammals and why?

1-3% because so much energy is used in maintaining a constant high body temperature.

Mutualism

A (+/+) interspecific interaction that benefits both species. Ex. The interaction between termites and the microorganisms in their digestive system is an example of obligate mutualism in which at least one species has lost the ability to survive on its own.

Transformation

A change in genotype and phenotype due to the assimilation of external DNA by a cell. In Griffith's experiment, the uptake of S-strain DNA by R-strain pneumonia bacteria coded in the R strains the capability to form the protective polysaccharide slime capsule that made the pneumonia bacteria so hard to find and kill by the immune system.

Depolarization

A reduction in the magnitude of the membrane potential. Often involves gated sodium channels. If a stimulus causes gated sodium channels to open, the membrane's permeability to Na+ increases.

Axillary bud

A structure that has the potential to form a lateral shoot, or branch. The bud appears in the angle formed between a leaf and a stem. Above each leaf scar is an axillary bud.

Life Table

Age specific summary of reproductive rates in a population

What allows for cell-differentiation?

Almost all cells in a multicellular organism contain an identical genome, but the subset of genes expressed in the cells of each type is unique, allowing these cells to carry out their specific function.

Protonephridia

An excretory system, such as the flame bulb system of flatworms, consisting of a network of tubules lacking internal openings.

What are the benefits of complex body plans over simple ones?

An external skeleton can protect against predators, and sensory organs can provide detailed information on the animal's surroundings. Internal digestive organs can bread down food gradually, controlling the release of stored energy. In addition, specialized filtration systems in CBP can adjust the composition of the internal fluid that bathes the anima's boss cells.

Biomanipulation

Application of top-down model to attempt to prevent algal blooms and eutrophication by altering the density of higher-level consumers instead of using chemical treatments. Should work in lakes with three trophic levels by increasing zooplankton density and thus decreasing algal populations. In lakes with 4 trophic levels, adding a top predator should have the same effect.

How do you create diversity of life out of polymers?

Arrangement of monomers; the particular linear sequence that the units follow + length of the polymer chain.

Tendons

Attach muscles to bones

Circannual Rhythm

Behavioral rhythms linked to the yearly cycle of seasons. Influenced by periods of the day.

Ester linkage

Bond formed by a dehydration reaction between a hydroxyl group and a carboxyl group.

Single-lens eyes

Found in some jellies and polychaete worms (invertebrates). Contains a pupil through which light enters, iris that contracts or expands to let light in, and a layer of photoreceptors behind the pupil. Muscles in the eye move the lens forward or backward to focus.

Pitch

Frequency of the sound wave

F2 generation

Generation formed boy allowing F1 hybrids to self pollinate

Survivorship Curve

Graphs of survival rates through the lifespan of an organism

Tundra

Grassland growing on permafrost; too cold for conifers; tussock grasses often present. Permafrost restricts the growth of plants (+wind).

Heterozygous

Having two different alleles for a gene

Juxtaglomerular Apparatus

JGA; A specialized tissue in nephrons that releases the enzyme renin in response to a drop in blood pressure or volume.

Why does water have such a high specific heat?

Much of the heat energy added to water breaking Hydrogen bonds between the water molecules. Not until most of these are broken are the water molecules free to bounce around faster and thus raise the temperature of the water. As the water cools, water molecules bounce slower, forming more Hydrogen bond and releasing lost of heat energy.

Homosporous

Of seedless vascular plants: having one type of sporangium that produces one type of spore, which typically develops into a bisexual gametophyte, as in most ferns

Heterosporous

Of seedless vascular plants: having two types of sporangia and producing two types of spores: mega/microsporangia

Hybrids

Offspring that result from an interspecific mating.

Describe the two free ends of the sugar-phosphate backbone.

One end has a phosphate attached to a 5' carbon (5' end), and the other end has a hydroxyl group on a 3' carbon (3' end).

Monogamy

One individual male mating with one female. Low dimorphism. Ex: Western gulls

Peritubular Capillary

One of the tiny blood vessels that form a network surrounding the proximal and distal tubules in the kidney

Roots

Organs that absorb water and nutrients from the soil. Roots also anchor vascular plants, hence allowing the shoot system to grow taller.

Afferent neurons

PNS neurons that carry sensory information to the CNS.

Globular proteins

Proteins which are roughly spherical

Symbiosis

Relationship in which individuals of two or more species live in direct and intimate contact with one another

Where is the site of protein synthesis

Ribosomes.

Pteridophytes

Seedless vascular plants such as club mosses, horsetails, and ferns

Nervous system in nofsegmented worms

Small brain and longitudinal nerve cords constitute the simplest clearly defined CNS.

Why is linear order of bases in a gene important?

Specifies the amino acid sequence of proteins.

Strata

Super-imposed layers of rock

Relative fitness

The contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals

Climate

The long term prevailing weather conditions in a give area. 4 components: temperature, precipitation, sunlight, and wind.

Excretion

The process that rids the body of nitrogenous metabolites and other metabolic waste products

Exponential Population Growth equation

dN/dt = r(inst) * N African Elephants in Kruger National Park

Draw an amino acid, ionized and unionized.

okay.

Explain the different ring structures of glucose

α: Hydroxyl group attached to the number 1 carbon is positioned below the plane of the ring. β: Hydroxyl group attached to the number 1 carbon is positioned above the plane of the ring.

What are the assumptions of the logistic growth model?

• Populations adjust instantaneously to growth • Regardless of population density, each individual added to a population has the same negative effect on population growth rate

Duplication (chromosome structure)

"Deleted" fragment becomes attached as an extra segment to a sister chromatid.

Equation for production efficiency

(Net Secondary Production x 100%)/Assimilation of primary production

Down Syndrome

1/830 children in the US. Trisomy of 21 chromosome. Frequency increases with age of mother. Sexually underdeveloped and sterile offspring

How mic solar radiation bombards earth each day?

10²² J. Most incoming solar radiation is absorbed, scattered, or reflected by clouds and dust in the atmosphere.

Effective Population for grizzlies?

125 bears.

Mole (mol)

6.02 * 10²³ - Avogadro's number

Antigen presenting Cells

A cell that upon ingesting pathogens or internalizing pathogen proteins generates peptide fragments that are bound by calss II MHC molecules and subsequently displays on the cell surface to T cells. Macrophages, dendritic cells, and B cells are the primary antigen presenting cells.

Shared ancestral acharacter

A character that originated in an ancestor of the taxon.

Cotyledons

A seed leaf of an angiosperm embryo. Some species have one cotyledon, other two.

Biological Species concept

A species is a group of populations whose members have the potential to interbreed in nature and produce viable fertile offspring- but do no produce viable, fertile offspring with members of other such groups.

Promoter

A specific nucleotide sequence in the DNA of a gene that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place.

Fibrous root system

A thick mat of slender roots spreading out below the soil surface. In plants that have fibrous root systems (most monocots), the primary root dies early on and does not form a taproot. Instead, many small roots emerge from the stem. Because this mat of roots holds the topsoil in place, plants such as grasses that have dense fibrous root systems are especially good at preventing soil erosion.

Atrioventricular Valve

AV valve; Lies between each atrium and ventricle. Anchored by strong fibers that prevent them from turning inside out. Pressure generated by the powerful contraction of the ventricles closes the av valves.

Sickle cell disease

Abnormal form of hemoglobin polymerizes into aggregates.

Ectopic

Abnormal in location

How do buffers work?

Accepts hydrogen ions from the solution when they are in excess, or donates hydrogen ions to the solution when they have been depleted. Most contain a weak acid and its corresponding base.

Proteins

Account for more than 50% of the dry mass of most cells. A biologically functional molecule made up of one or more polypeptides, each folded and coiled into a specific three-dimensional structure.

How does myelin heath work?

Action potentials are not generated in the regions between the nodes. Rather, the inward current produced during the rising phase of the action potential at a node travels within the axon all the way to the next node. There, the current depolarizes the membrane and regenerates the action potential. Action potentials propagate more rapidly in myelinated axons because the time-consuming process of opening and closing of ion channels occurs at only a limited number of positions along the axon.

What is the role of cytoplasmic determinants?

After fertilization, early mitotic divisions distribute the zygote's cytoplasm into separate cells. The nuclei of these cells may be exposed to different cytoplasmic determinants, depending on which portions of the zygotic cytoplasm a cell received. The combination of cytoplasmic determinants in a cell helps determine its developmental fate by regulating expression of the cell's genes during the course of cell differentiation.

Root system

All of a plant's roots, which anchor it in the soil, absorb and transplant minerals and water, and store food. Roots are almost never photosynthetic; they starve unless photosynthates are imported from the shoot system.

Hemoetherm

Animal that has a relatively constant body temperature. (River otter)

b

Annual per capita birth rate

3 categories of plant life cycle

Annuals, biennials, perennials

Opsonization

Antibodies bound to antigens on bacteria do no block infection, but instead present a readily recognizad structure for macrphages or neutrophils, thereby promoting phagocytosis. Because each antibody has two antigen-binding sites, antibodies can also facilitate phagocytosis by linking bacterial cells, viruses, or other foreign substances into aggregates. Phagocytosis enables macrophages to present antigens to and stimulate helper T cells, creating positive feedback loop.

Activation of complement system

Antibodies sometimes work together with the proteins of the complement system. Binding a complement protein to an antigen-anybody complex on a foregin cell triggers the generation of a membrane attack complex that forms a porre in the the membrane of the cell. Ions and water rush into the cell, causing it to swell and lyse. The result is lysis of foreign cells and produces factors that promote inflammation or stimulate phagocytosis.

Songs

Auditory displays used for courtship and defense of territory in insects, whales, birds. Control of the song may be mostly genetic, as in insect species, or mostly learned, as in whales, or a combination, as in many birds.

Nucleosome

Basic unit of DNA packing

Neurons

Basic units of the nervous system. Receives nerve impulses via cell body and extensions called dendrites. Transmit impulses to neurons, muscles, or other cells via extensions called axons.

Describe Oogenesis

Begins in the female embryo with the production of oogonia from primordial germ cells. The oogonia divide by mitosis to form cells that begin meiosis, but stop the process at prophase I before birth. These developmentally arrested cells, which are primary oocytes, each reside within a small follicle, a cavity lined with protective cells. At birth , the ovaries together contain about 1-2 million primary oocytes, of which about 500 will fully mature between puberty and menopause

Altruism

Behavior that helps another individual at some cost to the altruistic individual. Ex: Belding's ground squirrel alarms to the others in the group, that increases risk

What inputs affect the pacemaker?

Body temp, hormones, and physiological cues

Storage leaves

Bulbs, such as a cut onion, have a short underground stem and modified leaves that store food.

How does the trp operator work?

By itself, the trp operator is turned on, and RNA polymerase can bind to the promoter and transcribe the genes of the operon. The operon can be switched off by a protein called the trp repressor. The repressor binds to the operator and blocks attachment of RNA polymerase to the promoter, preventing transcription of the genes. A repressor protein is specific for the operator of a particular operon.

What is the effect of chromosomal changes?

Chromosomal changes that delete, disrupt or rearrange may loci are usually harmful.

Evidence for Evolution - Anatomical and molecular homologies

Closely-related organisms share features that make little sense except in the context of evolution. The forelimbs of all mammals, including humans, cats, whales, and bats, show the same arrangement of bones from the shoulder to the tips of the digits, even though the appendages have very different functions.

Thrombus

Clot formed within a blood vessel, blocking the flow of blood.

Sori

Clusters of sporangia produced by fern sporophylls, usually on the undersides of sporophylls.

What are the four emergent properties of water?

Cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a solvent.

Complement system

Consists of roughly 30 proteins in blood plasma. These proteins circulate in an inactive state and are activated by substances on the surface of many microbes. Activation results in a cascade of biochemical reactions that can lead to lysis or invading cells.

Organ

Consists of several types of tissues that together carry out particular functions.

Water-Conducting cells of the Xylem

Consists of two types of water-conducting cells, tracheids and vessel elements, are dead at functional maturity. Tracheids occur in the xylem of all vascular plants. When the living cellular contents of a tracheas or vessel element disintegrate, the cell's thickened walled remain behind, forming a nonliving conduit through which water can flow. The secondary walls of tracheids/vessel elements are often interrupted by pits. Water can migrate laterally between neighboring cells through the pits.

Compound eye

Consists of up to several thousand light detects call ommatidia, each with its own light-focusing lens.

Systole

Contraction phase of the cardiac cycle.

Sympathetic Division

Corresponds to arousal and energy generation (heart beat ++, digestion inhibited, adrenal medulla increases secretion of epinephrine, liver converts glycogen to glucose).

Disulfide bridge

Covalent bonds which form where two cysteine monomers, which have sulfhydryl groups on their side chains, are brought close together by the folding of the protein. The sulfur of one cysteine bond to the sulfur of the second rivets parts of the protein together.

Cuticle

Covering of the epidermis in many plant species that consists of wax and other polymers. The cuticle acts as waterproofing, helping prevent excessive water loss from aboveground plant organs, while also providing some protection from microbial attack.

Name diseases associated with misfiling polypeptides

Cystic fibrosis, Alzheimer's, PD, mad cow, dementia.

Nuclease

DNA cutting enzyme that excises damaged DNA strand, filling the resulting gap with nucleotides using the undamaged strand as a template with DNA Pol and Ligase in nucleotide excision repair.

Virus

DNA enclosed by a protective coat, often simply protein, which must infect a cell and take control over the cell's metabolic machinery to reproduce.

Genetic marker

DNA sequences that vary in the population. Such variation is the basis of different alleles.

Potential mechanisms for positive feedback of warming?

Decay of organic materials stored in permafrost in arctic. Methane hydrates in the arctic ocean Methane stored in arctic permafrost on land Deforestation of the Amazon leading to drier climate and accelerating the loss of rainforest.

Mitochondrial myopathy

Defect in protein complexes of the electron transport chain and ATP synthase, the products of most mitochondrial genes, cause weakness, intolerance of exercise, and muscle deterioration.

Leber's Hereditary optic neuropathy

Defects in protein complexes of the electron transport chain and ATP synthase, the products of most mitochondrial genes, causes sudden blindness in people as young as 20-30.

Ecological species concept

Defines species on ecological niche, the sum of how many members of the species interact with the nonliving and living parts of their environment. Can accommodate asexual/sexual, and emphasizes the role of natural selection as organisms adapt to different environments.

Cri du chat

Deletion in chromosome 5.

Vertebrate stretch receptors?

Dendrites of sensory neurons that spiral around the middle of certain small skeletal muscle fibers.

Branch points

Dichotomies that depict evolutionary relationships. Each branch point represents the divergence of two evolutionary lineages from a common ancestor

Structural isomers

Differ in the covalent arrangements.

Neutral variation

Differences in DNA sequence that do not confer a selective advantage or disadvantage. Usually occurs when there is a point mutation in a noncoding region of DNA. Also can occur because of the redundancy in the genetic code allows for the same amino acid to be encoded by different nucleotide sequences.

How is variation maintained?

Diploidy organisms Balancing Evolution Heterozygote advantage Frequency-Dependent Selection

Immunodefinciency

Disorder in which an immune system response to antigens is defective or absent. SCID means functional lymphocytes are rare or absent, meaning patients are susceptible to infections. Inborn (genetic/developmental). or Acquired (exposure to chemicals/biological agents).

Endometriosis

Disorder in which some cells of the uterine lining migrate to an abdominal location that is abnormal. Having migrated to a location such as an oviduct, ovary, or large intestine, the ectopic tissue responds to hormones in the bloodstream. Thus, the ectopic tissue swells and breaks down during each ovarian cycle, resulting in pelvic pain and abdominal bleeding.

What factors limit distribution of species?

Dispersal, Behavior, Habitat selection, biotic factors, abiotic env. factors

Antigen presentation

Display of the antigen fragment in an exposed groove of the MHC protein.

Why is recombination frequency between three alleles slightly greater than the distance between the three alleles as a whole?

Double Crossovers between alleles "cancel out" each other, contributing to the frequency between each of the closer pairs of genes

What are sources of chromosomal variation?

Duplication of genes due to errors in meiosis (ie. unequal crossing over) Slippage during DNA replication Or transposable elements.

What are the 3 mechanisms that contribute to the shuffling of alleles with sexual reproduction?

During crossover in meiosis, homologous chromosomes from each parent trade some of their alleles by crossing over. Also in meiosis, Independent assortment distributes these alleles at random into gametes. Lastly, because myriad possible mating combinations exist in a population, fertilization brings together gametes that are likely to have different genetic backgrounds.

Electrocardiogram

EKG; SA ode currents are recorded by electrodes placed on the skin.

Spatial summation

EPSP's produced nearly simultaneously by different synapses on the same postsynaptic neuron add together.

Mendel's Law of Independent Assortment

Each gamete will receive 1 homolog from each homologous pair (either maternal or paternal), but which homolog it gets is random. Occurs in Metaphase I of Meiosis.

Describe excretion in segmented worms?

Each segment of an annelid has a pair of metanephridia, which are immersed in coelomic fluid and enveloped by a capillary network. A ciliated funnel surrounds the internal opening of each mantenephridium. As the cilia beat, fluid is drawn into a collecting tubule, which includes a storage bladder that opens to the outside.

Maternal effect gene

Egg-polarity gene; Gene that, when mutant in the mother, results in a mutant phenotype in the offspring, regardless of the offspring's own genotype.

What are the benefits of internal fertilization?

Egs fertilized internally are sheltered from potential predators. More often associated with mechanisms that provide greater protection of the embryos and parental care of the young.

Describe Termination (translation)

Elongation proceeds until a stop codon reaches A site - there are no tRNA's with anticodons complementary to stop codons. Release factor protein binds to the stop codon and splits a water molecule to free the finished polypeptide from the last tRNA The ribosome dissociates into 2 subunits (costs 2 GTP) More than 1 ribosome may be moving down an mRNA mlc. at one time; these ribosome clusters are called polyribosomes.

What are the four main types of animal tissues?

Epithelial, connective, muscle, and nervous.

What do the antigen receptors of B cells bind to?

Epitopes of INTACT antigens on pathogens or circulating free in body fluids.

What do scientists use in place of bacteria for eukaryotic expression/cloning?

Eukaryotic cells such as yeasts: they are as easy to grow as bacteria, and they have plasmids. Also, since many eukaryotic proteins will not function unless they are modified after translation, and bacteria can't carry out these processes (yeast cells can't either if the cell is from a mammal).

Why is evapotranspiration a good measure of warmth and moisture?

Evapotranspiration measures the evaporation of water transpired by plants, meaning it becomes a measure of plant productivity and how often plants cycle water. These conditions are best met in warm climates with lots of moisture.

Two key factors that contribute to latitudinal gradients

Evolutionary history: Tropical communities are generally older than polar or temperate communities, which have repeatedly "started over" following major disturbances. Climate: The growing season in tropical forests is about five times as long as in the tundra communities of high latitudes. Biological time thus runs about five times as fast in the tropics as near the poles. + Sunlight + precipitation

Allergies

Exaggerated responses to vertain antigens called allergens. Induces mast cell to release histamine and other inflammatory chemicals when pollen grains enter the body and attach to antigen binding sites of IgE antibodies.

Community Ecology

Examines how species interactions, such as predation and competition, affect community structure and organization.

Urban Ecology

Examines organisms and their environment in urban settings.

How do scientists overcome differences in promoter and other DNA control sequences when trying to express a gene in bacteria?

Expression vectors & using a form of the gene that only includes the exons, since bacteria don't have noncoding DNA.

Analogous features

Features between species that share similar function but not common ancestry.

Biennials

Generally require two growing seasons to complete their life cycle, flowering and fruiting only in their second year. Turnips.

Charles Lyell

Geologist who incorporated Hutton's thinking into his proposal that the same geologic processes are operating today as in the past, and at the same rate.

Tissue

Group of cells, consisting of one or more cell types that together perform a specialized function.

Tissue

Groups of cells with a similar appearance and a common function.

Spores

Haploid cells released by mycorrhizal fungi that colonize soils through dispersion that forms new mycelia after germinating.

Exoskeleton

Hard covering deposited on an animals surface. Made of calcium carbonate secreted by a mantle. Cuticle (30-50% consists of chitin, a polysaccharide)

Overharvesting

Harvesting of wild organisms at rates exceeding the ability of their population to rebound. Ex.Marine fish targeted by industrial fishing typically see population declines of 85% in about 15 years. African Elephant/Rhino.

Effector forms of T cells

Helper T cells and cytotoxic t cells.

Choroid

Highly vascularized layer that supplies retina with lots of nutrients and heat disposal;

Where is color blindness gene located?

Human genes for red and green pigments are located on the X chromosome. Therefore men primarily get it.

What elements commonly bond with carbon atoms to form proteins, DNA, and carbohydrates?

Hydrogen (H), Oxygen (O), Nitrogen (N), Sulfur (S), Phosphorus (P)

What are carbon's most frequent bonding partners?

Hydrogen, oxygen, nitrogen.

How does te action potential move along the axon?

Immediately behind the traveling zone of depolarization caused by Na+ inflow is a zone of repolarization caused by K+ outflow In the re polarized zoned, the sodium channels remain inactivated. The inward current that depolarizes the axon membrane ahead of the action potential cannot produce another action potential behind it.

Littoral Zone

In a lake, the shallow, well-lit waters close to shore

Limnetic Zone

In a lake, the well-lit, open surface waters far from shore.

Endosperm

In angiosperms, a nutrient-rich tissue formed by the union of a sperm with two polar nuclei during double fertilization. The endosperm provides nourishment to the developing embryo in angiosperm seeds.

Why was the oxygen revolution bad for prokaryotes?

In certain chemical forms, oxygen attacks chemical bonds and can inhibit enzymes and damage cells, dooming many prokaryotic groups.

Describe Initiation (translation)

In eek cells, a small ribosomal subunit binds to an initiator tRNA (with Met attached) and then a mRNA molecule at the 5' cap. Then, it moves down the mRNA until the ribosomal subunit reaches the AUG stat codon on the mRNA. The initiator tRNA with the anticodon UAC and the Correct AA, Met, that is already bound to the small ribosomal subunit now binds to the AUG codon Large ribosomal subunit binds to complete the complex with the help of E from 1 GTP mol. Several proteins are required.

Reabsorption

In excretory systems, the recovery of solutes and water from filtrate

Set Point

In homeostasis in animals, a value maintained for a particular variable, such as body temperature or solute concentration

Gnetophyta

Includes 3 genera: Gnetum, ephedra, and Welwitschia. Some are tropical, whereas others live in deserts. Grouped by molecular data.

Bark

Includes all tissues external to the vascular cambium.

When does evapotranspiration increase?

Increases with the temperature and amount of solar energy available to drive evaporation and transpiration

HIV

Infects helper T cells by binding specifically to the CD4 accessory protein.RNA genome is reverse transcribed, and product DNA integrates into genome, directing production of new virsues. Rna also means higher mutation rate. Altered proteins on the surface of mutated viruses reduce interaction with antibodies and cytotixic T cells. ALSO , latency.

Ocean Currents effect on climate

Influence climate along the coasts of continents by heating or cooling overlying air masses that pass across the land. Because of the high specific heat of water, oceans and large lakes tend to moderate the climate of nearby land. During a hot day, when land is warmer than the water, air over the land heats up and rises, drawing a cool breeze from he water across the land. In contrast, because temperature drops more quickly over land than over water at night, air over the now warmer water rises, drawing cooler air from the land back out over the water and replacing it with warmer air from offshore. The west coast of northern Europe has a mild climate because the Gulf Stream carries warm water from the equator to the North Atlantic. As a result, northwestern Europe is warmer during winter than southeastern Canada, which is farther south but is cooled by the Labrador Current flowing south from Greenland.

Sidle-Cell disease

Inherited blood disorder; caused by the substitution of the amino acid Valine for the normal one, glutamic acid. This creates an abnormal hemoglobin molecule, and hydrophobic interactions between the proteins lead to their aggregation as a fiber, forming a fragile chain that deforms cells into a sickle shape.

Walls of arteries

Innermost Endothelium layer, then smooth muscle, then connective tissue. Thick and strong to accommodate blood pumped at high pressure. Elastic as well.

Endodermis

Innermost layer of the cortex. A cylinder one cell thick that forms the boundary with the vascular cylinder. The endodermis is a selective barrier that regulates passage of substances from the soil into the vascular cylinder

Conservation biology

Integrates ecology, physiology, molecular biology, genetics, and evolutionary biology to conserve biological diversity at all levels.

What is the relationship between size and metabolic rate?

Larger animals have more body mass and therefore require more chemical energy. Overall metabolic rate and body mass is constant relationship, whereas metabolic rate is proportional to body mass to the three-quarter power.

Purines

Larger of the two nitrogenous bases, with a six-membered ring fused to a five membered ring. Adenine (A) and guanine (G).

Macrophages

Larger phagocytic cells. Some migrate throughout the body, while others permanently reside in organs/tissues where they're likely to encounter pathogens.

Reservoirs of Phosphorus

Largest accumulations are in sedimentary rocks of marine origin. There are also large quantities of phosphorus in soil, in the oceans (in dissolved form) and in organisms. Because soil particles bind PO₄³⁻, the recycling of phosphorus tends to be quite localized in ecosystems.

How do fishes detect low-frequency waves?

Lateral line system along both sides of their body.

Apical Meristems

Localized regions of cell division at the tips of roots and shoots. Cells produced by apical meristems differentiate into the outer epidermis, which protects the body, and various types of internal tissues. Shoot apical meristems also generate leaves in most plants. Thus, the complex bodies have specialized below and aboveground regions.

Apical meristems

Located at the tips of roots and shoots, apical meristems provide additional cells that enable growth in length

Proximal Control Elements

Located close to the promoter.

Locus

Location of a gene on a chromosome.

Hibernation

Long-term torpor that is an adaptation to winter cold and food scarcity.

Why does biodiversity matter?

Loss of wild populations of plants closely related to agricultural species means a loss of genetic resources that could be used to improve crop qualities (outbreaks in rice) Products from aspirin to antibiotics were derived originally from natural sources (plants) 25% of the prescriptions in the US contain substances originally derived from plants. Taq polymerase, used in PCR, was found in bacterium that lived in hot springs in Yellowstone

How do mammals breathe?

Lower air pressure in their lungs below that of air outside their body by expanding thoracic cavity with muscle contraction. Gas flows from high to low pressure. Muscles controlling thoracic cavity relax, reducing volume, increasing pressure, expelling ear. Inhalation is active and requires work. Exhalation is usually passive.

Mating Systems

Mating systems and parental care reflect differences in requirements of the young for survival, monogamy being far more common in birds whose young cannot survive without lots of care from BOTH parents.

Palisade mesophyll

Mesophyll in eudicot leaves that consists of one or more layers of elongated parenchyma cells on the upper part of the leaf.

Start codon

Methionine

Nonequlibrium model of community change

Model that maintains that communities change constantly after being buffeted by disturbances.

Learning

Modification of behavior based on experiences

Horsetails

Monilophyte Arthrophytes: Stems have joints. Rings of small leaves or branches emerge from each joint, but the stem is the main photosynthetic organ. Large air canals carry oxygen to the roots, which often grow in waterlogged soil Some species have separate fertile and vegetative stems. Homosporous, with cones releasing spores that typically give rise to bisexual gametophytes.

Turner's Syndrome

Monosomy X in Females - only known viable monosomy in humans. X0, sterile.

Explain Thomas Hunt Morgan's Experiment

Morgan and his colleagues mated a wild-type, red-eyed female with a mutant white-eyed male. The resulting offspring had all red eyes, which Morgan then bred with an F1 red-eyed male to produce an F2 generation. The F2 generation showed a typical 3:1 ration, however, all white-eyed flies were males, suggesting the w trait must be recessive to the w+ trait, and this eye color gene is located on the x chromosome, without a corresponding locus on the y chromosome.

How does dispersal limit the distribution of species?

Movement of members of a species from their home range or densest concentrations Natural range expansions (cattle egrets) vs. species transplants (introduction of australian opossums into the forest of New Zealand by Europeans in order to create a fur resource)

Ventilation

Movement of the respiratory medium over the respiratory surface

Why do ecologists care about NPP?

NPP IS THE KEY MEASUREMENT BECAUSE IT REPRESENTS THE STORAGE OF CHEMICAL ENERGY THAT WILL BE AVAILABLE TO CONSUMERS IN THE ECOSYSTEM

Gamma-aminobutyric Acid (GABA)

Neurotransmitter at most inhibitory synapses in the brain. Binding GABA to receptors in postsynaptic cells increases membrane permeability to CL-, resulting in an IPSP

Saturated fatty acids

No double bonds between carbon atoms composing a hydrocarbon chain in fatty acids, allowing as many hydrogen atoms as possible to bond to the carbon skeleton. Solid at room temperature.

Random Dispersion

No pattern is apparent (dandelions in a field... but is this distribution really random or are there damp spots with better growing conditions in the field where more seeds germinated and survived?) Random and even are NOT the same.

Do cows digest cellulose?

No. They carry cellulose-digesting prokaryotes and protists in their gut, which hydrolyze the cellulose of hay and grass and convert the glucose to other compounds that nourish the cow. Termites are the same. Some fungi can digest cellulose in soil and elsewhere, helping recycle chemical elements within Earth's ecosystems.

Is exponential growth ever sustainable?

No. Unlimited growth does not occur for long in nature, where individuals typically have access to fewer resources as a population grows.

Heart rate

Number of bpm

How does Translation regulate gene xp?

Occurs most commonly at initiation stage. For some mRNAs, the initiation of translation can be blocked by regulatory proteins that bind to specific sequences or structure within the untranslated region at the 5' or 3' end, preventing the attachment of ribosomes. Translation of all mRNAs in a cell may be regulated simultaneously. Such global control requires activation or inactivation of one or more of the protein factors required to initiate translation. This mechanism plays a role in starting translation of mRNAs stored in eggs, or when some plants are exposed to light after darkness.

Directional selection

Occurs when conditions favor individuals exhibiting one extreme of a phenotypic range, thereby shifting a population's frequency curve for the phenotypic character in one direction or the other. Common when the environment changes or members of a population migrate to a new habitat.

What leads to a net loss of fluid from capillaries?

On average, blood pressure is greater than the opposing forces, leading to a net loss of fluid from capillaries. Net loss is generally at arterial end of these vessels, where blood pressure is highest.

Cardiac cycle

One complete sequence of pumping and filling.

Myoglobin

Oxygen storing protein found in muscles. Oxygen binds more tightly to myoglobin than hemoglobin.

Efferent neurons

PNS neurons that carry instructions from the CNS to muscles, glands, and endocrine cells.

Peat

Partially decayed organic material. The low temperature, pH, and oxygen level of peatlands also inhibit decay of moss and other organisms in boggy peatlands. Peatmoss has large dead cells that can absorb roughly 20 times the moss's weight in water. Cover 3% of Earth's land surface. Contain roughly 30% of the world's soil carbon.

Innate behaviors

Patterns of activity that show little or no variation between individuals and are developmentally fixed throughout life (strong genetic component

Optimal foraging model

Patterns of behavior that maximize food gathering while minimizing energy cost of the behavior AND risk of predation. Example: Northwestern crow ideal height to drop whelks is 5 meters. This is also the height preferred by crows.

Meristems

Perpetually dividing, unspecialized tissues that divide when conditions permit, leading to new cells that elongate and become specialized. Except for dormant periods, most plants grow continuously.

Dendritic Cells

Phagocytic cells that mainly populate tissues, such as skin, that contact the environment. Stimulate adaptive immunity against pathogens they encounter and engulf.

piRNA

Piwi-associated RNAs; usually 24-31 nucleotides long, processed from longer, single-stranded RNA precursor. Induce formation of heterochromatin, blocking expression of some parasitic DNA elements in the genome known as transposons. Play an indispensable role in the germ cells of many animals, where they appear to help reestablish appropriate methylation patterns in the genome during gamete formation.

Phases

Plant developmental stages that occur within a single region, the shoot apical meristem.

Monocots

Plant species with only one cotyledon, or seed leaf. About 70k species (1/4 of angiosperm species). Includes orchids, grasses, and palms, maize rice, wheat.

Dicots

Plant species with two cotyledons, or seed leaves.

Chaparral or Mediterranean scrub

Plants adapted for cool, wet winters and very hot, dry summers.

Nitrogen Cycle Forms available to life

Plants can assimilate Ammonium (NH4+) and nitrate (NO3-) and some organic forms, such as amino acids. Various bacteria can use all of these forms as well as nitrite (NO2-). Animals can use only organic forms of nitrogen

Glycogen

Polysaccharide made of glucose monomers.

What is the energetic hypothesis?

Possible explanation for why food chains are so short. Suggests that the length of a food chain is limited by the inefficiency of energy transfer along the chain. Only about 10% of the energy stored in the organic matter of each trophic level is converted to organic matter at the next trophic level. Thus, a producer level consisting of 100 kg of plant material can support about 10 kg of herbivore biomass and 1 kg of carnivore biomass. This hypothesis predicts that food chains should be relatively longer in habitats of higher photosynthetic production, since the amount of energy stored in primary producers is greater than in habitats with lower photosynthetic production.

Gray matter

Primarily made up of neuron body cells in the brain.

Neutralization

Process in which antibodies bind to proteins on the surface of a virus. The bound antibodies prevent infection of a host cell, neutralizing the virus.

Stamens

Produce microspores that develop into pollen grains containing male gametophytes. Consists of a filament and an anther. Modified sporophyll.

Myelin sheath

Produced by Oligodendrocytes in the CNS and Schwann cells in the PNS. During development, these specialized glia wrap axons in many layers of membrane. The membranes forming these layers are mostly lipid, a poor conductor of electrical current.

Why do certain aquatic ecosystems have inverted biomass pyramids?

Producers (phytoplankton) grow, reproduce, and are consumed so quickly by the zooplankton that they develop a large population size, or standing crop. Thus, phytoplankton have a short turnover time. Because phytoplankton continually replace their biomass at such a rapid rate, they can support a biomass of zooplankton bigger than their own biomass. Nevertheless, because phytoplankton have much higher production than zooplankton, the pyramid of production for this ecosystem is still bottom heavy.

Leaf primordia

Projections shaped like a cow's horns that emerge along the sides of the apical meristem from which leaves develop. Shoot elongation is due to the lengthening of internode cells below the shoot tip.

Allele frequency

Proportion of said allele in a population

James Hutton

Proposed that Earth's geologic features could be explained by gradual mechanisms, such as valleys being formed by rivers.

ABC Hypothesis

Proposes that three classes of genes direct the formation of the four types of floral organs. Each class of organ identity genes is switched on in two specific whorls of the floral meristem.

Defensive proteins

Protect against disease; antibodies

Periderm

Protective tissue in woody plants that replaces the epidermis in older regions of stems and roots.

Why are evolutionary adaptations that enable sufficient gas exchange found primarily within the body?

Protects delicate tissues from abrasion/dehydration and allows for streamlined body contours.

Antigen Receptor

Protein site of binding between an antigen and a B/T cell.

Thin filaments

Protein structures whose major component is the globular protein actin. Two strands of polymerized actin are coiled around one another.

Repressor

Protein that binds to the operator to prevent RNA polymerase from moving from promoter to structural genes

Mediator proteins

Proteins on activators that interact with proteins at the promoter of an operon to help assemble and position the initiation complex on the promoter.

Histone

Proteins responsible for the first level of DNA packing in chromatin.

mRNA

RNA molecule that carries a genetic message from the DNA to ribosomes

Saltatory conduction

Rapid transmission of nerve impulses along an axon, resulting from the action potential jumping from one node of Ranvier to another, skipping the myelin sheathed regions of membrane.

Rate of elongation is about 500 nukes/sec in bacteria and 50/sec in humans.

Rate of elongation in humans vs. bacteria

Stem cell

Relatively unspecialized cell that can both reproduce itself indefinitely and, under appropriate conditions, differentiate into specialized cells of one or more types.

Toxic Accumulation

Release of an immense variety of toxic chemicals, including thousands of synthetic compounds previously unknown in nature, with little regard for the ecological consequences

What did Mendel remove to achieve cross pollination of two plants?

Removed the immature stamens and then dusted pollen from another plant onto the altered flowers.

What happened with the cloning of the tadpole?

Removed the nucleus of an unfertilized or fertilized egg and replace it with the nucleus of a differentiated cell (nuclear transplantation). The nucleus should be able to direct development of the recipient cell into all tissues and organs of an organism. Transplanted nucleus from less-differentiated cell was often able to support normal development of the egg into a tadpole. Nuclear transplantation from fully differentiated cell into enucleated egg usually stopped developing before the tadpole stage, though.

Human impact on lakes

Runoff from fertilized land and dumping of wastes lead to nutrient enrichment, which can produce algal blooms, oxygen depletion, and fish kills.

What are most animal fats?

Saturated; hydrocarbon chains of the fatty acids lack double bonds, allowing for flexibility so fat molecules can pack tightly together.

Two types of sclerenchyma cells

Sclereids and fibers. Specialized entirely for support and strengthening.

Migration2

Seasonal movements of large numbers of animals over long distances

Homology

Similarity resulting from common ancestry.

When does primary/secondary growth occur in woody plants?

Simultaneously. As primary growth adds leaves and lengthens stems and roots in the younger regions of a plant, secondary growth increases the diameter of stems and roots in older regions where primary growth has ceased.

Mate choice

Strong selection exists for traits that accurately reflect reproductive fitness of a male or female Ex: Length of eye stalks in stalk-eyed flies.

Ethology

Study of behavior.

Habitat differentiation

Subpopulation exploits a habitat or resource not used by the parent population. Hawthorne tree vs. Apple tree. North American apple maggot fly.

Missense mutation

Substition of nucleotide that changes one amino acid into another one

Pentose

Sugars with 5 carbons

Serial Endosymbiosis

Supposes that mitochondria evolved before plastids through a series of endosymbiotic events.

Main factors controlling primary production in terrestrial ecosystems

Temperature and Moisture, N and P.

Secondary Immune Response

The adaptive immune response elicited on second or subsequent exposures to a particular antigen. The secondary immune response is more rapid, of greater magnitude, and of longer duration than the primary immune response.

Shoot System

The aerial portion of a plant body, consisting of stems, leaves, and (in angiosperms) flowers. Depends on waters and minerals that roots absorb from the soil.

Ecological Footprint

The aggregate land and water area required by each person, city, or nation to produce all the resources it consumes and to absorb all the waste it generates.

What determines the three dimensional structure of the amino acid sequence of each polypeptide?

The amino acid sequence.

Critical Load

The amount of added nutrient, usually nitrogen or phosphorus, that can be absorbed by plants without damaging ecosystem integrity.

Why is the arrangement of Hox genes important?

The arrangement of Hox genes formed clusters. The order of the genes in each cluster corresponded to the order of the body regions in which they were expressed, meaning the depth of the similarty between different animals extended no just to the sequence of the genes, but to their organization in clusters.

Trans isomers

The arrangement of the molecule with the X's on opposite sides.

Cis isomers

The arrangement with both X's on the same side of the double bond.

Nucleic acid hybridization

The base pairing of one strand of a nucleic acid to the complementary sequence on a strand from another nucleic acid molecule

Sarcomeres

The basic contractile units of skeletal muscle, which make up myofibrils. Actin filaments are attached to the Z line and thus to the rest of the cell cytoskeleton.

Macroevolution

The broad pattern of evolution above the species level.

Nerves

The bundles of axons of neurons.

How much has Earth warmed since 1900? Why?

The burning of fossil fuels and deforestation are increasing the concentrations of carbon dioxide and other greenhouse gases in the atmosphere to the point that the Earth has warmed .8° C.

Fovea

The center of the visual field, where there are no rods, but a very high density of cones.

Vascular Cylinder

The central root stele in angiosperms, consisting of xylem and phloem

Receptor potential

The change in membrane potential

Limiting nutrient

The element that must be added for production to increase, (often N, or P, or Fe).

Sieve plates

The end walls between sieve tube elements. Have pores that facilitate the flow of fluid from cell to cell along the sieve tube.

Why did Miller's experiment feature an electric spark? Why didn't it explode?

The energy in the spark forced the stable compounds to react by raising the activation energy. No O₂

Kinetic energy

The energy of movement. The faster a molecule moves, the greater its kinetic energy.

Countercurrent exchange

The exchange of a substance or heat between two fluids flowing in opposite directions. In fish gills, the fluids are blood and water. Because blood flows in opposite direction as water passing over the gills, at each point in its travel blood is less saturated with O2 than the water it meets.

Differential gene expression

The expression of different genes by cells with the same genome.

Sturtevant

The farther apart two genes are, the higher the probability that a crossover will occur between them, and therefore the higher the recombination frequency.

Sexual Reproduction

The fusion of haploid gametes to forms a diploid cell.

Describe the bonds in a hydrocarbon.

The great majority are relatively nonpolar carbon-to-hydrogen linkages.

Primary Immune Response

The initial adaptive immune response to an antigen, which appears after a lag of 10-17 days.

Renal medulla

The inner portion of the vertebrate kidney, beneath the renal cortex. Supplied with blood by a renal artery and drained by a renal vein. Within lie tightly packed excretory tubules ands associated blood vessels. Excretory tubules carry and process a filtrate. Nearly all of the fluid from the filtrate is reabsorbed into the surrounding blood vessels and exits the kidney through the renal vein. The remaining fluid leaves the excretory tubules as urine, is collected in the inner renal pelvis, and exits the kidneys via ureter.

Gene Therapy

The introduction of genes into an afflicted individual for therapeutic purposes. (Bone marrow cells = good because they multiply their whole life.

Leaf

The main photosynthetic organ. Leaves intercept light, exchange gases with the atmosphere, dissipate heat, defend themselves from herbivores/pathogens. In general consists of a blade and a petiole.

Carbon Reservoirs

The major reservoirs of carbon include fossil fuels, soils, and sediments of aquatic ecosystems, the oceans (dissolved carbon compounds, plant and animal biomass, and the atmosphere (CO2). The largest reservoir is sedimentary rocks such as limestone; however, this pool turns over very slowly.

Midrib

The major vein that runs down the center of a blade in the vascular tissue of leaves.

Why do we have disaccharides?

The osmotic effect of a disaccharide is twice that of a monosaccharide, meaning its very much a more compact energy form in terms of what can dissolve in water.

Integumentary System

The outer covering of the body, consisting of the skin, hair, and nails (claws/hooves).

Bioenergtics

The overall flow and transformation of energy in an animal, which determines nutritional needs and is related to size, activity, and environment.

Aphotic Zone

The part of an ocean or lake beneath the photic zone, where light does not penetrate sufficiently for photosynthesis to occur.

Trophic efficiency

The percentage of production transferred from one trophic level to the next. ~10% in most ecosystems.

Nodes

The points at which leaves are attached

Foot

The portion of a bryophyte sporophyte that gathers sugars, amino acids, water, and minerals from the parent gametophyte via transfer cells. Embedded in the archegonium.

Realized Niche

The portion of a species' fundamental niche that it actually occupies

Urinary bladder

The pouch where urine is stored prior to elimination.

Ligand-gated ion channel

The receptor protein that binds and responds to neurotransmitters. Clustered in the membrane of the postsynaptic cell, directly opposite the synaptic terminal. Binding of the neurotransmitter to a particular part of the receptor opens the channel and allows specific ions to diffuse across the postsynaptic membrane.

Ovulation

The release of mature eggs at a certain point in the reproductive cycle.

Evaporation

The removal of heat from the surface of a liquid that is losing some of its molecueles as gas.

Incomplete dominance

The situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele Example: When homozygous red snapdragons are crossed with homozygous white snapdragons, all F1 hybrids have pink flowers. This is because f1 generation has less red pigment than the red homozygotes.

Codominance

The situation in which the phenotypes of both alleles are fully exhibited in the heterozygote, and produce a phenotype with both characteristics Example: Human MN blood group is determined by codominant alleles for two specific molecules located on the surface of rbc's, the M and N molecules. Both M and N molecules are present on the abc's of individuals heterozygous for the M and N alleles.

Continental drift

The slow movement of Earth's continents over time

Tetanus

The smooth, sustained contraction of a motor unit when there is no time for relaxation between arriving AP's.

Transcription

The synthesis of RNA using information in the DNA

Biomass

The total mass of all organisms in a habitat. More diverse habitats produce more biomass than single-species plots.

Meristem Identity genes

The transition from vegetative growth to flowering is associated with the switching of these identity genes. The protein products of these genes are transcription factors that regulate the genes required for the conversion of the indeterminate vegetative meristems to determinate floral meristems

Why was Volhard and Wieschaus's experiment daunting?

The two set out to identify all of the genes that affect segment formation in fruit flies. The first reason is that there were so many genes: 14k, and those genes that specifically affected segment formation might just be needles in a haystack. Second, mutations affecting a process as fundamental as segmentation would sure by embryonic lethals. Because these organisms never reproduce, they cannot be bred for studies. The researches dealt with this problem by looking for recessive mutations which can be propagated in heterozygous flies that act as genetic carriers. Third, cytoplasmic determinants in the egg were known to play a role in axis formation, so the researches knew they would have to study the mother's genes as well as those of the embryo.

Veins

The vessels that carry blood back to the heart.

Membrane potential

The voltage (charge difference) caused by the attraction of opposite charges across the plasma membrane.

What does the mark-recapture method assume?

This method assumes that marked and unmarked individuals have the same probability of being captured or sampled, that the marked organisms have mixed completely back into the population, and that no individuals are born, die, immigrate, or emigrate during the resampling interval.

Threatened species

Those species considered likely to become endangered in the near future.

Cornea

Tough, clear window into eyeball (continuation of sclera but transparent); filled with aqueous humor so that it bulges; thus, focuses light on retina if light source is more than 20 feet away.

General transcription factors

Transcription factors which are essential for the transcription of ALL protein-dicing genes. A few bind to the TATA box within the promoter, but most bind to proteins, including other transcription factors and RNA poly. II.

Convection

Transfer of heat by the movement of air or liquid past a surface.

Transport proteins

Transport of substance from one part of the body to the other (i.e. hemoglobin), or across membranes.

What are humans doing to marine food chains when we harvest primary or secondary consumers and not the tertiary consumers that we have traditionally taken?

Trawling, where boats drag weighted nets across the seafloor, scrape and scour corals and other life on the sea floor.

Retina

Triple layer of cells derived from a cup-like outgrowth of the brain. Optic nerve neurons closes to lens/farthest from choroid. Bipolar neuron layer in the middle Layer of rod and cone cells next to pigmented epithelium and choroid; note that rods and cones are modified neurons and that the retina is the only part of the nervous system that can be seen without dissection

What did Griffith do?

Trying to develop a vaccine against pneumonia, Griffith found that when he killed pathogenic bacteria (S strain of pneumonia virus) with heat and then mixed the cell remains with living bacteria of the nonpathogenic R strain, some of the living cells became pathogenic, and was inherited by all the descendants of the transformed bacteria. He did this by taking different combos of strains and injecting them into mice. Called the phenomenon Transformation

Müllerian mimicry

Two or more unpalatable species resemble each other. The more unpalatable prey there are, the more quickly predators learn to avoid prey with that particular appearance. Ex. The cuckoo bee and yellow jacket.

Explain competitive exclusion with Ecological Niches

Two species cannot coexist permanently in a community if their niches are identical. However, ecologically similar species CAN coexist in a community if one or more significant differences in their niches arise through time.

Where are co-expressed eukaryotic genes found?

Typically scattered over different chromosomes. Coordinate gene expression depends on the association of a specific combination of control elements with every gene of a dispersed group. Activator proteins in the nucleus that recognize the control elements bind to them, promoting simultaneous transcription of the genes, no matter their location in the genome.

Zone of elongation

Typically, a few millimeters behind the tip of the root. Most of the growth occurs as root cells elongate- sometimes to more than ten times their original length. Cell elongation in this zone pushes the tip farther into the soil. Meanwhile, the root apical meristem keeps adding cells to the younger end of the zone of elongation. Even before the root cells finish lengthening, many begin specializing in structure/function

Flower

Unique angiosperm structure specialized for sexual reproduction. Specialized shoot that can have up to four types of modified leaves (sporphylls) called floral organs.

How do flatworms excrete wastes?

Units called protonephridia form a network of dead-end tubules. The tubules, which are connected to external openings, branch throughout the flatworm body, which lacks a coelom (body cavity). Cellular units called flame bulbs cap the branches of each protonephridium. Consisting of a tubule cell and a cap cell, each flame bulb has a tuft of cilia projecting into the tubule. During filtration, the beating of the cilia draws water and solutes from the interstitial fluid through the flame bulb, releasing filtrate into the tubule network. The processed filtrate moves outward through the tubules and empties as urine into the environment.

Microfibrils

Units of groups of parallel cellulose molecules in plants.

Why is carbon the backbone of life?

Unparalleled in its ability to form molecules that are large, complex, and varied, making possible the diversity of organisms that have evolved on Earth.

What does "hydrogenated" mean?

Unsaturated fats have been synthetically converted to saturated fats by adding hydrogen. Produces trans fats, too.

Helicase

Unwinds parental double helix at replication forks

Why is there higher NPP in the oceanic regions closer to the arctic?

Upwellings of limiting nutrients > greater NPP by phytoplankton > more zooplankton to eat phytoplankton > greater whale activity.

Explain excretion in Humans

Uric produced by each kidney exits through the ureter which drains into the urinary bladder. From there Urine is expelled from the bladder through the urethra. Sphincter muscles near the junction of the urethra and bladder regulate urination

How do you reduce ecological footprints?

Use less energy, eat less food, drink less water, buy less clothes, use the car less

Sepals

Usually green leaves that enclose the flower before it opens.

Why is water cohesive?

Water's high polarity allows it to form many hydrogen bonds, linking water molecules at any given moment. This makes water more structurally sound than most other liquids, and holds the substance together.

What land plant adaptations allow them to overcome the challenges of life on land?

Waxy cuticle Stomata Specialized xylem/phloem cells for transporting water and nutrients (NONVASCULAR PLANTS DON'T HAVE THIS) Secondary compounds that serve to reinforce cellulose for added rigidity (lignin) or to protect plants from herbivores (alkaloids, tannins, terpenes)

Maximum Parsimony

We should first investigate the simplest explanation that is consistent with the facts.

Tinbergen's Questions

What stimulus elicits the behavior, and what physiological mechanisms mediate the response? How does the animal's experience during growth and development influence the response? How does the behavior aid survival and reproduction? What is the behavior's evolutionary history?

Describe how bonds form between two monomers

When a bond forms between two monomers, each monomer contributes part of the water molecule that is released during the reaction: One monomer provides a hydroxyl group (-OH), while the other provides a hydrogen (-H). The reaction is repeated as monomers are added to the chain one by one, making a polymer.

Founder Effect

When a few individuals become isolated from a larger population, this smaller group may establish a new population whose gene pool differs from the source population. Probably accounts for the relatively high frequency of certain inherited disorders among isolated human populations.

Paedomophosis

When a sexually mature stage of a species may retain body features that were juvenile structures in ancestral species. (Axolotl Salamander). Such an evolutionary alteration can produce animals phenotypically very different from their ancestors.

Indeterminate growth

When growth occurs throughout a plant's life. This is possible because meristems

Heterozygote Protection

When harmful alleles that are recessive can be hidden from selection, allowing them to persist for generations by propagation in heterozygous individuals, since their harmful effects are masked by the more favorable dominant allele.

When are duplications of chromosome segments not harmful?

When it is a small piece of DNA being duplicated, the effect is usually not harmful.

Reinforcement

When natural selection strengthens pre zygotic barriers to reproduction because hybrids are less fit. Eventually, hybrids gradually cease to be formed.

Double Fertilization

When one fertilization event produces a zygote and the other produces a triploid cell. Unique to angiosperms

Plant cell differentiation

When plant cells become specialized in structure and function during the course of development.

Population Dynamics

When populations fluctuate from year to year or place to place, as influenced by many factors and in turn affect other species.

What are the 3 main variables life history entails?

When reproduction begins (the age at first reproduction or age at maturity), how often the organism reproduces, and how many offspring are produced per reproductive episode.

When are chromosomal changes not harmful?

When such changes leave genes intact, they may not affect the organism's phenotype. In rare cases, chromosomal rearrangements may even be beneficial: translocating part of one chromosome to a different one could link genes in a way that produces a positive effect.

Cell body (neuron)

Where most of a neuron's organelles, including nucleus, are located

Cross fostering study

Young of one species plced in the care of the adults from another species Ex: Male Cali Mice (aggressive + helicopter parents). Male White-footed mice (not aggressive).

Habitat loss

accounts for 73% of the species that have become extinct, endangered, vulnerable or rare.

tRNA

brings amino acids to the ribosome during the synthesis of a polypeptide.

m

per capita death rate

Amino group

(-NH₂); Amine; Acts as a base, can pick up an H⁺ from the surrounding solution. Example: Glycine

Observations of Evolution - Drug-Resistant bacteria

2 years after penicillin was introduced, more than 20% of S. aureus strains contained the enzyme penicillinase, which could destroy penicillin. Later, researchers used a powerful antibiotic, methicillin, to deactivate a protein that bacteria use to synthesize their cell walls, but within two years, again, different S. aureus populations exhibited variations in which some individuals could synthesize their walls using a protein not affected by methicillin. Overtime, these resistant strains survived, leading to what is now known as MRSA.

Shoot apical meristem

A dome-shaped mass of dividing cells at the shoot tip

Megaspore

A spore from a heterosporous plant species that develops into a female gametophyte.

Heart murmer

Abnormal sound made when blood squirts backward through a defective valve.

Light Limitation

About half of the solar radiation is absorbed in the first 15m of water. Even in "clear" water, only 5-10% of the radiation may reach a depth of 75m.

Enzymatic proteins

Accelerate select chemical reactions; Digestive enzymes.

Cause of Ozone depletion

Accumulation of chlorofluorocarbons (CFCs), chemicals once widely used in refrigeration and manufacturing. In the stratosphere, chlorine atoms released from CFCs react with ozone, reducing it to molecular O2. Subsequent chemical reactions liberate the chlorine, allowing it to react with other ozone molecules in a catalytic chain reaction. Most apparent over Antarctica, where cold stable air allows the reactions to take place in polar, stratospheric clouds.

Acid rain problems

Acidic water dissolves helpful minerals in the soil and then washes them away before they can be used to help trees/plants grow Damages leaves Acidification of streams and lakes (As lakes and streams become more acidic, the numbers and types of fish and other aquatic plants and animals that live in these waters decrease.)

Trisomic

Addition of chromosome; 2n+1; occurs if nondisjunction fails to separate sister chromatids in Meiosis II

Where do animals store fat?

Adipose cells; adipose tissue cushions vital organs as the kidneys, and a layer beneath the skin insulates the body.

Mosaicism + x-linked examples

After an X chromosome is inactivated in a particular cell, all mitotic descendants of that cell have the same inactive X. This, if a female is heterozygous for a sex linked trait, about half her cells will express one allele, while the others will express the alternate allele. Tortoise shell cat has two alleles for the fur color X-linked gene. In humans, mosaicism can be observed in a recessive X-linked mutation that prevents the development of sweat glands. A woman who is heterozygous for this trait has patches of normal skin and patches of skin lacking sweat glands.

Recessive allele

An allele whose phenotypic effect is not observed in a heterozygote.

Osmoregulator

An animal that controls internal osmolarity independent of the osmolarity of the external environment.

Osmoconformer

An animal which is isosmotic with its surroundings. All osmoconformers are marine animals.

Poikilotherm

An animal whose body temperature varies with its environment (largemouth bass, bats and hummingbirds)

Restriction Enzymes

An endonuclease that recognizes and cuts DNA molecules foreign to a bacterium to protect it. The enzyme cuts at specific nucleotide sequences, called restriction sites. Each restriction enzyme is specific, with a particular short DNA sequence (site). The DNA of a bacterial cell is protected from the cell's own restriction enzymes by the addition of methyl groups to adenines or cytosines within the sequences recognized by the enzymes.

What is the amount of material that must be exchanged proportional to?

Body volume.

List the macromolecules

Carbs, proteins, nucleic acids

What features influence microclimate?

Casting shade, altering evaporation from soil, or changing wind patterns. Forest trees often moderate the microclimate below them.

Tropical Forest

Characterized by great plant and animal species richness, by high rainfall and warm temps year round; soils are often poor because nutrients are rapidly recycled back into living plants.

What are the 3 patterns of dispersion?

Clumped, Uniform, and Random

What's the biological significance of adhesion?

Columns of water in xylem vessels are supported against gravity by their adhesion to the cellulose walls of the vessels.

Ligaments

Connect bones at joints

What determines the axes in Drosophilia?

Cytoplasmic determinants that are localized in the unfertilized egg provide positional information for the placement of anterior-poster and dorsal-ventral axes even before fertilization.

DNA Replication

DNA Synthesis; The process by which a DNA molecule is copied

Hermaphroditism

Each individual has both male and female reproductive systems, allowing ANY two individuals to mate. Each animal donates and receives sperm during mating. Some species hermaphrodites can also self-fertilize.

All stimuli represent forms of?

Energy

What are the effects of ocean acidification?

Extra hydrogen ions combine with carbonate ions (CO₃²⁻) to form bicarbonate ions (HCO₃⁻), reducing the carbonate ion concentration. This could prove detrimental to calcification, which requires carbonate ions, and deals with building animal shells and corals.

List interactions between angiosperms and animals

Flowers + Pollinators Fructivores and seed dispersal Grasses + grazers

Gametophore

Gamete producing structure on bryophyte gametophyte

Allopatric Speciation

Gene flow is interrupted when a population is divided into geographically isolated subpopulations.

Extranuclear/Cytoplasmic genes

Genes that are located in organelles in the cytoplasm, not on nuclear chromosomes or even in the nucleus. These organelles reproduce themselves and transmit their genes to daughter organelles. Organelle genes are not distributed to offspring according to the same rules that direct the distribution of nuclear chromosomes during Meiosis, so they do not display Mendelian inheritance.

Three levels of biodiversity

Genetic Diversity, species diversity, ecosystem diversity.

Who was Friedrich Wöhler and what did he do?

German chemist (1828) who tried to make an "inorganic" salt, ammonium cyanate, by mixing solutions of ammonium ions (NH₄⁺) and cyanate ions (CNO⁻), but instead made urea, a different organic compound.

Who was Stanley Miller and what did he do?

Grad student at UChicago (1953), who helped bring the abiotic (nonliving) synthesis of organic compounds into the context of evolution. He set up a closed system which mimicked the conditions thought at that time to have existed on the early Earth. The experiment yielded a variety of organic molecules that are common in organisms, such as formaldehyde, hydrogen cyanide, amino acids, and hydrocarbons.

Heterozygote Advantage

Greater reproductive success of heterozygous individuals compared wth homozygotes; tends to preserve variation in a gene pool.

Threats to biodiversity

Habitat loss, invasive species, over harvesting, global change

Punnet Square

Handy diagrammatic device for predicting the allele composition of offspring from a cross between individuals of known genetic makeup.

How does heat exchange between objects of two different temperatures?

Heat passes from the warmer object to the cooler one until the two are the same temperature.

What does lignified tissue do?

Helped enable vascular plants to grow tall. Their stems became strong enough to provide support against gravity, and they could transport water and mineral nutrients high above the ground.

What is the biological significance of water's high heat of vaporization?

Helps moderate Earth's climate: Solar heat absorbed by tropical seas is consumed during evaporation of surface water, then released as the water condenses into rain after having circulated poleward. Also, causes severity of steam burns.

Monohybrids

Heterozygous for the one particular character being followed in the cross

Hypertension

High blood pressure. Damages the endothelium that lines the arteries, promoting plaque formation.

Paralogous Genes

Homology results from gene duplication; hence, multiple copies of these genes have diverged from one another within a species.

Why are some reproduction cycles controlled by environment?

Hormones are secreted with environmental cues as a way to conserve resources, reproducing only when sufficient energy is available.

Proximate causation

How a behavior occurs or is modified

List the polar side chains.

Hydrophilic; Serine, Threonine, Cysteine, Tyrosine, Asparagine, Glutamine.

Hemocytes

Immune cells that travel throughout the body in the hemolymph.

Why is NEP useful to ecologists?

Its value determines whether an ecosystem is gaining or losing carbon over time. A forest may have a positive NPP but still lose carbon if heterotrophs release it as CO2 more quickly than primary producers incorporate it into organic compounds.

Synapse

Junctions where each branched end of an axon transmits information to another cell.

How many genes need to change for reproductive isolation?

Just a change in 1 locus. Monkey Flower.

Smooth Muscle

Lacks striations. Involuntary. Found in the walls of the digestive tract, urinary bladder, arteries, and other internal organs. Spindle shaped. Responsible for involuntary activities, such ass arterial constriction/stomach churning.

Describe Summer in lakes with winter ice cover'

Lake regains a distinctive thermal profile, with warm surface water separated from cold bottom water by a narrow vertical zone of abrupt temperature change, called a thermocline

Embryophytes

Land plant; highlights the significance of multicellular dependent embryos of land plants as derived traits.

Cycadophyta

Large cones, palm like leaves. Flagellated sperm, indicating their descent from seedless vascular plants that had motile sperm. Most endangered of all plant groups: 75% of species are threatened by habitat destruction and other human actions.

Mass extinction

Large numbers of species become extinct worldwide. Usually habitat is destroyed or environment changes unfavorable.

Simple Columnar Epithelium

Large, Brick-shaped cells of simple columnar epithelia are often found where secretion or active absorption is important. Lines the intestines, secreting digestive juices and absorbing nutrients

Stromatolites

Layered rocks that form when certain prokaryotes bind thing films of sediment together.

Ependymal Cells

Line the ventricles of the brain and have cilia that promote circulation of the cerebrospinal fluid

Basal Taxon

Lineage that diverges early in the history of a group and hence lies on a branch that originates near the common ancestor of the group.

Plasma

Liquid matrix in which vertebrate blood cells are suspended. 55% of blood is plasma. In plasma are ions and proteins that, with blood cells, function in osmotic regulation, transport, and defense.

Diastolic pressure

Lower pressure during relaxation of the ventricles when the elastic walls of the arteries snap back.

What are the smaller clades of vascular plants?

Lycophytes, monilophytes, gymnosperms, angiosperms

Storage Roots

Many plants, such as the common beet, store food and water in their roots

Cytogenic maps

Maps of chromosomes which locate genes with respect to chromosomal features.

How do different types of activators come to be present in two differentiated cells?

Materials placed into the egg by the mother set up a sequential program of gene regulation that is carried out as cells divide, and this program coordinates cell differentiation during embryonic development.

Law of Conservation of Mass

Matter, like energy, cannot be created or destroyed. Since we cannot obtain matter from a source, like the sun, mass in conserved in ecosystems, and chemical elements are continually recycled within them.

Plant-pollinator interactions

May affect the rates at which new species form. On a flower with bilateral symmetry, an insect pollinator can obtain nectar only when approaching from a certain direction. This constraint makes it more likely that pollen is placed on a part of the insect's body that will come into contact with the stigma of a flower of the same species. Such specificity of pollen transfer reduces gene flow between diverging populations and could lead to increased rates of speciation in plants with bilateral symmetry.

Are diets rich in saturated fats good?

May contribute to the cardiovascular disease, atherosclerosis, which causes plaque buildup in your blood vessels.

How do you determine metabolic rate?

Measure an animal's rate of heat loss (calorimeter). Measure amount of O2 or CO2 produced by an animal's cellular respiration. Also, record the rate of food consumption, energy content of food, and the chemical energy lost in waste products

Intermediate disturbance hypothesis

Moderate levels of disturbance foster greater species diversity than do high or low levels of disturbance. High levels of disturbance reduce diversity by creating environmental stresses that exceed the tolerances of many species or by disturbing the community so often that slow-growing or slow-colonizing species are excluded. At the other extreme, low levels of disturbance can reduce species diversity by allowing competitively dominant species to exclude less competitive ones.

Chemical group

Molecules that can replace one or more hydrogens of a hydrocarbon, and may participate in chemical reactions, or contribute to function indirectly by their effects on molecular shape.

Multicellular gametangia

Multicellular organs called gametangia are the site of gamete production. The gametophytes of seed plants are so reduced in size that the archegonia and antheridia have been lost in many lineages.

Sporangia

Multicellular organs within sporophytes that produce spores. Within a sporangia is a sporocyte. The outer tissues of the sporangium protect the developing spores until they are released into the air.

Ammonia

NH3. Very toxic. Doesn't cost a lot of energy to make. Can only be tolerated at low concentrations. Found in invertebrates and many in aquatic species.

What are the main ideas of natural selection?

Natural selection is a process in which individuals that have certain heritable traits survive and reproduce at a higher rate than other individuals because of those traits Over time, natural selection can increase the match between organisms and their environment If an organism changes, or if individuals move to a new environment, natural selection may result in adaptation to these new conditions, sometimes giving rise to new species.

Interneurons

Neurons in the brain or ganglia that integrate the sensory input, taking into account the immediate context and the animal's experience. Form the local circuits in the connecting neurons in the brain.

Endorphins

Neuropeptides that function as natural analgesics, decreasing pain perception

Biogenic amines

Neurotransmitters synthesized amino acids that includes norepinephrine, which is made from tyrosine.

Two types of phagocytic cells in the mammalian body

Neutrophils and Macrophages, Dendritic cells, and eosinophils

Asexual reproduction

New individuals are generated without the fusion of egg and sperm

Nitrogen Cycle

Nitrogen enters ecosystem thru fixation: Conversion of N2 to forms that can be used to synthesize organic nitrogen compounds. Certain bacteria, lightening, and volcanic activity, fix nitrogen naturally. In plants, legume crops fix nitrogen via bacteria in their root nodules. Some bacteria carry out denitrification, reducing nitrate to nitrogen gases. (Fixation in root nodules, assimilation, Decomposition, ammonification, nitrification, uptake of amino acids, denitrification, N2) Nitrogen inputs from human activities now outpace natural inputs on land. Industrially produced fertilizers.

Are genes expressed together, with proteins produced concurrently, found in operons in eukaryotes?

No.

Heme

Nonpolypeptide component in each subunit of hemoglobin that combines with an iron atom that binds oxygen.

Biogeochemical cycles

Nutrient cycles that involve both biotic and abiotic components.

Four types of environmental change that humans are bringing about:

Nutrient enrichment, toxin accumulation, climate change and ozone depletion

Oligotrophic lakes

Nutrient poor and oxygen-rich lakes. Good water clarity and low prime productivity. May become more eutrophic over time as runoff adds sediments and nutrients. Amount of decomposable organic matter in bottom sediments is low. Lower surface area relative to depth.

Brain

Organ of the central nervous system where information is processed and integrated.

Peripheral nervous system

PNS; Neurons that carry information into and out of the CNS.

Nociceptors

Pain receptors to detect stimuli that reflect noxious (harmful) conditions

3 types of symbiosis

Parasitism, mutualism, and commensalism

When infant mortality is high

Parents are likely to have more children to ensure that some reach adulthood.

How do amino acids bond?

Peptide bond; Two amino acids are position so that the carboxyl group of one is adjacent to the amino group of the other, they can become joined by a dehydration reaction with the removal of a water molecule, forming a covalent bond called a peptide bond.

How many different families of homeodomains are there?

Perhaps two-dozen. Hox, pax-6, Dll, and tin man all belong to four distinct families. These genes' protein families all have more similar proteins within each family than compared to those of other families.

Neutrophils

Phagocytic cells that circulate in the blood, are attracted by signals from infected tissues and then engulf and destroy the infecting pathogens.

Anatomical homologies in embryos

Pharyngeal arches and post-anal tails in vertebrate embryos can only be explained by a common ancestor.

What does selection act on?

Phenotype directly. It acts on the genotype indirectly via how the genotype affects the phenotype.

The Carbon Cycle

Photosynthesis by plants and phytoplankton removes substantial amounts of atmospheric CO2 each year. This quantity is approximately equaled by CO2 added to the atmosphere through cellular respiration by producers/consumers. The burning of fossil fuels and wood is adding significant amounts of additional CO2 to the atmosphere. Over geologic time, volcanoes are also a substantial source of CO2.

Iris

Pigmented muscle band that regulates how much light reaches the retina. Contraction of RADIAL BAND = dilation of pupil. Contraction of CIRCULAR BAND = constriction. This neuromuscular synapse is under autonomic nervous system control, and uses acetylcholine as a neurotransmitter.

Change in Nucleotide vs. Change in regulation?

Pit1X. Noticed Sticklebacks in lake populations have less spines than in ocean populations. Gene comparison revealed it was a difference in coding sequence.

Simple squamous epithelium

Platelike cells that function in the exchange of material by diffusion. Thin and leaky- lines blood vessels and the air sacs of the lungs.

Nutrient limits in Long Island phytoplankton

Pollution from duck farms adds N and P to coastal water off Long Island. Scientists cultured the phytoplankton with water collected from several sites, identified as A-G. They added either ammonium, or phosphate to some of the cultures. The addition of ammonium caused heavy phytoplankton growth in the cultures, but the addition of phosphate did not. The researchers concluded nitrogen to be the limiting nutrient.

nucleic acids

Polymers made of monomers called nucleotides

What is the large carnivore hypothesis?

Possible explanation for why food chains are so short. Carnivores tend to be larger at successive trophic levels. The size of a carnivore and its feeding mechanism put some upper limit on the size of food it can take into its mouth. Except in a few cases, larger carnivores cannot live on very small food items because they cannot obtain enough food in a given time to meet their metabolic needs.

Describe replication in E.coli's circular chromosome

Proteins that initiate DNA replication recognize the origin of replication and attach to the DNA, separating the two strands and opening up a replication "bubble." Replication of DNA then proceeds in both directions until the entire molecule is copied.

Interferons

Proteins that provide innate defense by interfering with viral infections. Virus-infected body cells secrete interferons, which induce nearby uninfected cells to produce substances that inhibit viral replication, limiting the cell-to-cell spread of viruses.

HSP 70

Proteins which are ATP-Binding chaperone proteins which bind to ATP to expose pockets of hydrophobic R groups, allowing the protein to complete folding.

Negative pressure breathing

Pulling, rather than pushing, air into their lungs.

Sodium-potassium pump

Pump that uses the energy of ATP hydrolysis to actively transport Na+ out of the cell and K+ into the cell. Transports three Na+ out of the cell for every two K+ that it transports in.

Vascular Rays

Radial files of mostly parenchymal cells that connect the secondary xylem and phloem. Produced by the initials oriented perpendicular to the axis of the stem or root.

Descending Loop of Henle

Reabsorption of water continues as the filtrate moves into the descending limb of the Loop of Henle. Numerous water channels formed by aquaporin proteins make the transport epithelium freely permeable to water. There are almost no channels for salt and other small solutes, resulting in very low permeability for these substances. For water to move out of the tubule by osmosis, the interstitial fluid bathing the tubule must be hyper osmotic to the filtrate. The osmolarity of the interstitial fluid increases progressively from the outer cortex to the inner medulla of the kidney. As a result, the filtrate loses water and increases in solute concentration all along its journey down the descending limb.

How do ganglions work?

Receives information from an array of rods and cones, each of which responds to light coming from particular location. Together, the rods and cones that are feeding information to one ganglion cell define a RECEPTIVE FIELD - the part of the visual field to which that ganglion can respond. The fewer rods/cones supplying a single ganglion cell, the smaller the receptive field is. A SMALLER RECEPTIVE FIELD TYPICALLY RESULTS IN A SHARPER IMAGE.

How is neurotransmitter signaling terminated?

Receptor activation and postsynaptic response cease when neurotransmitter molecules are cleared from the synaptic cleft. The removal of neurotransmitters can occur by simple diffusion or inactivation by enzymatic hydrolysis.

How do land animals deal with the threat of dehydration?

Reduce water loss with waxy cuticle. Be nocturnal, which reduces evaporative water loss because of the lower temperature and higher humidity of night air. Drink/eat moist foods. Produce water metabolically through cellular respiration.

Why do some organisms have problems with edges?

Reduced biodiversity and a preponderance of edge-adapted species.

Vasoconstriction

Reduces blood flow and heat transfer by decreasing the diameter of superficial vessels.

Multifactorial

Referring to a phenotypic character that is influenced by multiple genes and environmental factors

Is regulation of trp and lac positive or negative gene regulation? Why?

Regulation of trp and lac operons involved the negative control of genes, because the operons are switched off by the active form of the repressor protein.

Why don't plants store fats?

Relatively immobile, so they can function with bulky energy storage in the form of starch.

Certainty of paternity

Relatively low in most species with internal fertilization because acts of mating and birth are separated over time.

Why does NS favor bacteria that expresses only genes whose products are needed by the cell?

Resources are scarce, and bacteria that can conserve resources and energy have a selective advantage over cells that are unable to do so.

Why its regulation of gene expression important?

Respond to signals from their external and internal environments. Cell specialization in multicellular organisms, which are made up of different types of cells.

Receptor proteins

Response of cell to chemical stimuli; proteins in the dendrites of neurons.

How are iPS cells made?

Retroviral vector introduces stem cell master regulator genes using a retroviral cloning vector into a fully differentiated cell. The cells are then cultured in a medium that would support the growth of stem cells, yielding an iPS cell

Taproot system

Root system of tall, erect plants with large shoot masses. Usually develops from the primary root and helps prevent the plant from toppling. In taproot systems, the role of absorption is restricted largely to lateral roots. A taproot, although energetically expensive to make, allows the plant to be taller, thereby giving it access to more favorable light conditions and, in some cases, providing an advantage for pollen and seed dispersal. Can also be specialized for food storage.

Sinoatrial Node

SA node; Pacemakes; A group of autorhytmic cells located in the wall of the right atrium, near where the superior vena cava enters the heart. Gap junctions speed rate which impulse travels to heart cells; Impulses first spread rapidly through the walls of the atria, causing atria to contract in unison.

Trans fats

Saturated and unsaturated fats with trans double bonds.

Watson and Crick

Saw Rosalind Franklin's x-ray crystallography image of DNA to find DNA was a "right handed," two-stranded double helix, with both strands running antiparallel and the sugar-phosphate backbone on the outside of the molecule, and the hydrophobic nitrogenous bases in the molecule's interior, away from the surrounding aqueous solution.

Tropical grasslands (savanna)

Scattered trees where grasses compete with woody plants for water and space (ex. Serengeti of Africa or pampas of S. America)

Marine Benthic zone

Seafloor of deep ocean, nutrient poor except around volcanic vents with their communities of chemoautotrophic bacteria and tube worms.

Loop

Section in the secondary structure without α helixes or β pleated sheet due to irregular, inconsistent hydrogen bonding.

What are the floral organs?

Sepals, petals, stamen, and carpels

Given an example of resource partitioning

Seven species of Anolis lizards live in close proximity, and all feed on insects and other small arthropods. However, competition for food is reduced because each lizard species has a different preferred perch, thus occupying a distinct niche. A. distichus has longer leg length to be able to run on leaves quicker. A. insolitus has shorter leg length comparative to its longer body to better grip and wrap around branches.

Epithelia

Sheets of tightly packed cells that line organs and body cavities as well as external surfaces

Intertidal Zone

Shoreline area exposed at low tide and covered at hight tide; inhabitants must withstand huge variations in temp and water availability.

Where is the Y chromosome homologous with the X?

Short segments at either end of the Y chromosome are the only regions that are homologous with regions of the X. These homologous regions allow the x and Y chromosomes in males to pair and behave like homologs during meiosis in the testes.

Effector cells

Short-lived cells that take effect immediately against the antigen and any pathogens producing that antigen

Transcription factory

Site at which loops of chromatin from the same and different chromosomes extend from individual chromosomal territories into specific sites at the nucleus. Thought to be area specialized for a common function.

Soredia

Small clusters of hyphae with embedded algae.

Brood bodies

Small plantlets that detach from the parent plant and grow into new, genetically identical copies of their parent.

Why does water have such a high heat of vaporization?

So many Hydrogen bonds between neighboring molecules must be broken before those molecules are free to enter the gaseous phase; the highest energy molecules leave the liquid first.

If reproduction is a primary instinct, why do humans in developed societies choose to have few or no children?

Social change and the rising educational and career aspirations of women in many cultures encourage women to delay marriage and postpone reproduction

Ediacaran biota

Soft bodied organisms that lived from 600 to 535 million years ago.

What causes differences in clock speed?

Some mutations are selectively neutral. If most are neutral, and have little/no effect on fitness, the Rate of evolution of those neutral mutations should be regular, like a clock. If the exact sequence of amino acids that a gene species is essential to survival, most of the mutational changes will be harmful and only a few will be neutral. As a result, such genes change only slowly.

What accounts for diversity for simple sugars?

Spatial arrangement of their parts around asymmetric carbons, location of carbonyl group, length of the molecule.

Guard cells

Specialized epidermal cells that flank the stomatal pore, and regulate the opening and closing of the pore.

Haustoria

Specialized hyphae which the fungi use to extract nutrients from, or exchange nutrients with, their plant hosts.

Adipose Tissue

Specialized loose connective tissue that stores fat in adipose cells distributed throughout its matrix. Adipose tissue pads and insulates the body and stores fuel as fat molecules. Swells when fat is stored/shrinks when used for fuel.

Stomata

Specialized pores which support photosynthesis by allowing the exchange of CO2 and O2 between the outside air and the plant. Stomata are also the main avenues by which water evaporates from the plant; in hot, dry conditions, the stomata close, minimizing water loss.

Aristotle's evolution hypothesis

Species as fixed life forms with "affinities" that could be arranged on a ladder of increasing complexity.

Outgroup

Species or group of species from an evolutionary lineage that is known to have diverged before the lineage that includes the species being studied

Fern Life Cycle

Sporangia release spores. Most fern species produce a single type of spore that develops into a bisexual photosynthetic gametophyte. (n) Each gametophyte develops sperm-producing organs called antheridia and egg producing organs called archegonia. Although this simplified diagram shows a sperm fertilizing an egg from the same gametophyte, in most fern species a gametophyte produces sperm and eggs at different times. Typically, an egg from one gametophyte is fertilized by a sperm from another. (n) Sperm use flagella to swim to eggs in archegonia. An attractant secreted by archegonia helps direct the sperm. (n) FERTILIZATION A zygote develops into a new sporophyte, and the young plant grows out from an archegonium of its parent, the gametophyte. (2n) On the underside of the sporophyte's reproductive leaves are spots called sori. Each sorus is a cluster of sporangia. (2n) MEIOSIS

Why does every living thing use the L enantiomer amino acids, and not.

Standardizes the orientation of the amino acids, so there's no problems with the sequence of the primary structure. If there were both groups used, the likelihood of getting a consistent protein shape and function would be too low.

Turnover time

Standing crop compared to production.

"Strangling" aerial roots

Strangler fig seeds germinate in the crevices of tall trees. Aerial roots grow to the ground, wrapping around the host tree and objects such as the comabodian temple. Shoots grow upward and shade out the host tree, killing it.

Cellulose

Structural polysaccharide; most abundant organic compound on earth; polymer of glucose; glucose monomers in the ß configuration. Never branched, allowing hydroxyl groups on its glucose monomers to hydrogen bond with the hydroxyls of other cellulose molecules lying parallel to it.

rRNA

Structure: Combines with proteins to form ribosomal subunits Each ribosome has an mRNA binding site and 3 tRNA binding sites, P, A, and E. Function: Act as a plastic, moving framework that holds mRNA and tRNA's together, that contains the ribozyme that joins AA's together to build proteins, and that moves down the mRNA.

Homologous structures

Structures in different species that are similar because of common ancestry.

Exaptations

Structures that evolve in one context but become co opted for another function.

How do evolutionary novelties arise?

Structures that originally played one role gradually acquire a different one. (Bones in jaw went to ear). Arise in series of steps that benefit owners at every stage.

Molecular mass

Sum of the masses of all the atoms in a molecule (in daltons).

Estivation

Summer Torpor, slows metabolism, enabling animals to survive long periods of high temperatures and scarce water.

Pangaea

Supercontinent. Ocean basins become deeper, sea levels lower, shallow coastal seas drain. Most marine species inhabited shallow waters- the formation of Pangaea destroyed much of that habitat.

Structural proteins

Support; keratin for hair, horns, feathers, and other skin appendages. Spider silk. Collagen in animal connective tissue.

Glial cells; glia

Supporting cells that nourish neurons, insulate the axons of neurons, and regulate the extracellular fluid surrounding neurons. Sometimes function in replenishing certain groups of neurons and in transmitting information

Primase

Synthesizes an RNA primer at 5' end of leading strand and at 5' end of each Okazaki fragment of lagging strand. Does NOT require existing platform because it does NOT check the pairing of the previous nuke and therefore has a 10-100x higher error rate than DNA polymerases.

Toll-like Receptor

TLR; mammalian receptors that bind to fragments of molecules normally absent from the vertebrate body but characteristic of a set of pathogens. Detection of invading pathogens in mammals triggers phagocytosis and destruction.

PCR

Technique used to amplify many copies of a specific target DNA segment. Denaturation: Heat briefly to separate DNA strands Annealing: Cool to allow primers to form hydrogen bonds with ends of target sequence Extension: Taq polymerase adds nucleotides to the 3' end of each primer

How do temperature and total thermal energy differ?

Temperature is not reliant on the body of matter's volume, while total thermal energy is, meaning a pot of hot coffee, although hotter in temperature than a swimming pool, has less thermal energy.

What are the abiotic factors that influence the distribution and abundance of organisms?

Temperature, light, water, and nutrients.

Punctuated Equilibria

Term that describes those periods of apparent stasis punctuated by sudden change.

Anther

Terminal sac where pollen is produced in angiosperms. At tip of stamen.

What negative feedback mechanisms control sex hormone production in males?

Testosterone regulates blood levels of GnRH, FSH, and LH through inhibitory effects on the hypothalamus and anterior pituitary. In addition, inhibit, a hormone that in males is produced by Sertoli cells, acts on the anterior pituitary gland to reduce FSH secretion.

r(inst)

The instantaneous per capita rate of increase

Nucleoside

The portion of a nucleotide without any phosphate groups.

Neritic Zone

The shallow region of the ocean overlying the continental shelf

Food chain

The transfer of food energy up the trophic levels from its source in plants and other autographs (primary producers) through herbivores (primary consumers) to carnivores (secondary, tertiary, and quaternary consumers) and eventually to decomposers.

Zoonotic Pathogens

Those pathogens transferred to humans from other animals, either through direct contact with an infected animal or by means of an intermediate species, called a vector. Ex. Lyme Disease. Vector: Ticks.

Introducd Species

Those that humans move intentionally or accidentally from the species' native locations to new geographic regions. Ex. Japanese knotweed in NE. Free from predators, parasites, and pathogens that limit their populations in their native habitats, such transplanted species may spread rapidly through a new region. Contribute to about 40% of the extinctions recorded since 1750.

Muscle Tissue

Tissue consisting of long muscle cells that can contract, either on its own or when stimulated by nerve impulses.

Multiplication Rule

To determine the probability that two more independent events will occur together in some specific combination, we multiple the probability of one even by the probability of the other event

Eudicot roots (primary growth)

Xylem has a starlike appearance in cross section, and the phloem occupies the indentations between the arms of the xylem "star"

How long do hydrogen bonds last

A few trillionths of a second, but they're constantly reforming with a succession of partners

Respiratory Pigments

A protein that transports oxygen in blood or hemolymph, greatly increasing the amount of O2 that can be carried in the circulatory fluid. Consist of a metal bound to a protein.

Connective tissue

Animal tissue that functions mainly to bind and support other tissues, having a sparse population of cells scattered through an extracellular matrix

Why does water have such a high surface tension?

At the interface between water and air is an ordered arrangement of water molecules, hydrogen bonded to one another and to the water below.

Why is genomics important?

Evolution, finding genetic basis for diseases, conservation.

Describe Termination in transcription

In Euk cells, AAUAAA on the RNA transcript or some close variant acts as the polyadenylation signal sequence and signals the end of the transcription unit which codes for 1 polypeptide - termination occurs 10-35 nucleotides downstream In pork. cells termination sequences have several GC pairs followed by several AT pairs and the transcription unit often codes for all of the enzymes in a metabolic pathway.

Standing Crop vs. NPP

NPP = amount of NEW biomass added in a given period of time Standing Crop = Total biomass of all photosynthetic autotrophs present.

Why is inbreeding bad?

Probability of passing on recessive traits increases greatly if many and woman are close relatives. This is because people with recent common ancestors are more likely to carry the same recessive alleles than are unrelated people. Thus, consanguineous matings are more likely to produce offspring homozygous for recessive traits- including harmful ones.

Sliding filament model

The thin and thick filaments ratchet past each other, powered by myosin molecules.

Countercurrent Exchange

The transfer of heat (or solutes) between fluids that are flowing in opposite directions. As warm blood moves from the body core in the arteries, it transfers heat to the colder blood returning from the extremities in the veins. Heat is transferred along the entire length of the exchanger, maximizing the rate of heat exchange.

How did Lyell and Hutton influence Darwin

Their theory was that geologic changed results from slow, continuous actions rather than sudden events, suggesting the Earth was much older than it was believed to be. He later reasoned that another system of gradual change would result in evolution.

What causes ocean acidification?

When CO₂ gas dissolves in seawater after being burned, it reacts with water to form carbonic acid, which lowers ocean pH.

When is gene regulation said to be positive?

When a regulatory protein interacts directly with the genome to switch transcription on.

Coordinately controlled

When a single "on-off switch" can control a whole cluster of functionally related genes.

Parthenogenesis

A form of asexual reproduction in which an egg develops without being fertilized. Occurs in certain species of bees, wasps, and ants. Progeny may be either haploid or diploid.

Innate Immunity

A form of defense common to all animals that is active immediately upon exposure to a pathogen and that is the same whether or not the pathogen has been encountered previously

Bohr Shift?

A lowering of the affinity of hemoglobin for oxygen, caused by a drop in pH. Facilitates the release of Oxygen from hemoglobin in the vicinity of active tissues.

Protonema

A mass of green, branched, one-cell-thick filaments produced by germinating moss spores. Has a large surface area that enhances absorption of water and minerals. In favorable conditions, a protonema produces one or more "buds." Each of these bud like growths has an apical meristem that generates a gamete-producing gametophore. Together, a protonema and one or more gametophores make up the body of a moss gametophyte.

Endothelium

A single layer of flattened epithelial cells in the central lumen of blood vessels.

Epidermis

A single tissue, consisting of a layer of tightly packed cells. Protects plants from water loss/disease. In roots, water and minerals absorbed from the soil enter through the epidermis, especially in root hairs. In shoots, specialized epidermal cells called guard cells are involved in gaseous exchange.

Sticky end

A single-stranded end of a double stranded restriction fragment. These short extensions can form hydrogen bonded base pairs with complementary sticky ends on any other DNA molecules cut with the same enzyme.

Corepressor

A small molecule that cooperates with a repressor protein to switch an operon off (ex. Tryptophan)

Aqueous solution

A solution in which the solute is dissolved in water, and water is therefore the solvent.

Organs

A specialized venter of body function composed of several different types of tissues.

Endangered species

A species "in danger of extinction throughout all or a significant portion of its range"

Loose connective tissue

Binds epithelia to underlying tissues and holds organs in place. Includes all three types of connective tissues. Found in the skin and throughout the body.

Single Strand Binding Protein

Binds to and stabilizes single stranded DNA until it is used as a template

Serotonin

Biogenic amine released in the brain that affects sleep, mood, attention, and learning.

Anatomy

Biological form

What are the neurons that make up the Retina?

Bipolar cell receives information from several rods or cones. Ganglion cell gathers input from several bipolar cells. Horizontal and amacrine cells integrate information across the retina.

Oceanic pelagic biome

Covers 70% of Earth's surface with open ocean but is relatively unproductive due to shortage of nutrients such as Iron requirements by phytoplankton.

Monohybrid Cross

Cross between heterozygotes

1k-2k nucleotides long in E. coli and 100-200 nukes in eukaryotes

How long is an Okazaki fragment?

Although codons GAA and GAG both specify glutamic acid, neither of them specifies any other amino acid. The redundancy in the code is not altogether random. In many cases, codons that are synonyms for a particular amino acid differ only in the third nucleotide base of the triplet.

Importance of redundancy patterns?

Ant-Fungus Farms

Leaf-cutter ants scour tropical forests in search of leaves, which they cannot digest on their own, but carry back to their nests to feed to the fungi. As the fungi grow, their hyphae develop specialied swollen tips that are rich in proteins and carbohydrates. The ants feed primarily on these nutrient rich tips. Not only do the fungi break down plant leaves into substances the ants can digest, but they also detoxify plant defensive compounds that would otherwise kill or harm ants. Bacteria on ant bodies produces anti-fungal compounds that suppress invasive molds.

Demographic transition

Movement from a stable population with a high birth rate and a high death rate to a stable population with a low birth and death rate. This transition always includes a time of rapid population growth in which death rate falls but birth rate remains high.

Contractile and motor proteins

Movement; actin and myosin for muscle contraction

Skeletal muscle

Moves bones and body. Each fiber is single cell with multiple nucleus.

Describe differentiation with MyoD

MyoD protein stimulates the myoD gene further and activates genes encoding other muscle-specific transcription factors, which in turn activate genes for muscle proteins. MyoD also turns on genes that block the cell cycle, thus stopping cell division. The non dividing myoblasts fuse to become mature multinucleate muscle cells, also called muscle fibers.

What does protein structure depend on, beside normal folding?

Physical and chemical conditions of the proteins environment. Changes in pH, salt concentration, temperature, or other aspects can destroy the weak chemical bonds and interactions within a protein.

Chorionic Villus Sampling (CVS)

Physician inserts a narrow tube through the cervix into the uterus and suctions out a tiny sample of tissue from the placenta. Yields immediate karyotype.

Ectoparasites

Parasites that feed on the external surface of a host Ex. Ticks and lice

Endoparasites

Parasites that live within the body of their host Ex. Tapeworms

Photoreceptors

Sensory cells that contain light-absorbing pigment molecules.

Inflammatory response

The changes brought about by signaling molecules released upon injury or infection. Dilated capillaries leak fluid into neighboring tissues, causing localized swelling.

How do photopsins affect how we see color?

The brain's perception of intermediate hues depends on the differential stimulation of two or more classes of photopsin-containing cones.

Humoral immune Response

The branch of adaptive immunity that involves the activation of B cells and that leads to the productions of antibodies, which defends against bacteria and viruses in body fluids.

Polarity

The condition of having structural or chemical differences at opposite ends of an organism.

Menopause

The cessation of ovulation and menstruation. Ovaries lose their responsiveness to FSH and LH.

Plate tectonics

The continents are part of great plates of Earth's crust that essentially float on the hot, underlying portion of the mantle. Movements in the mantle cause the plates to move over time- continental drift.

Phylogeny

The evolutionary history of a species or group of species

Primary Transcript

The initial RNA transcript from any gene, including those specifying RNA that is not translated into protein

Positional information

The molecular cues that control pattern formation, collectively, as decided by cytoplasmic determinants and inductive signals.

Photic Zone

The narrow top layer of an ocean or lake, where light penetrates sufficiently for photosynthesis to occur

Pericycle

The outermost cell layer in the vascular cylinder. Lateral roots arise from meristematically active regions of pericycle. Adjacent to and just inside the endodermis. Emerging lateral roots destructively push through the cortex and epidermis.

What about control elements is important in regulating transcription of a gene?

The particular combination of control elements in an enhancer for a gene.

Dispersion

The pattern of spacing among individuals within the boundaries of the population.

Logistic Population Growth model

The per capita rate of increase approaches zero as the population size nears the carrying capacity.

Morphogenesis

The process that gives a tissue, organ, or organisms its shape and determines the positions of cell types

Evapotranspiration

The total amount of water transpired by plants and evaporated from a landscape.

Standing Crop

The total biomass of photosynthetic autotrophs present.

Gene flow

The transfer of alleles into or out of a population due to the movement of fertile individuals or their gametes.

Spatial Learning

Use of landmarks to recognize spatial distribution of food, nest, mates Ex: Digger wasps pinecone-nest experiment (Tinbergen)

Amniocentesis

Used to determine if an individual has Tay-Sachs. Physician inserts a needle into the uterus and extracts about 10 ml of amniotic fluid. Tests for disorders are performed on the DNA of cells in the laboratory. Karyotype takes weeks to produce

Biological augmentation

Uses organisms to add essential materials to a degraded ecosystem Lupines planted to raise N concentrations in soil.

Suberin

Waxy, hydrophobic material deposited as cork cells mature. Waxy cork layer thus functions as a barrier that helps protect the stem or root from water loss, physical damage, and pathogens.

Describe the two pax-6 Experiments in "Endless Forms Most Beautiful"

When the Pax-6 gene was manipulated so that it was turned on in other parts of the fly, eye tissues were induced on wings, legs, and other parts of the body. This and the Pax-6 mutant effect showed that Pax-6 was a "master gene" for eye development. The second experiment was to introduce the mouse pax-6 gene into flies so that it was also turned on in weird places in the fly. The results were the same: fly tissues were induced to form eye structures, even when coming from mouse DNA.

When does exponential population growth occur?

When all members of the pop. have enough food and other limiting resources and reproduce at their full potential. Although the maximum rate of increase is constant, the population accumulates more new individuals per unit of time when it is larger than when it is small; thus, all curves > 0 approach slope ∞ When r(inst) > 0 and is constant at each instant in time.

Lymhpatic system

A network of tiny vessels intermingled among capillaries of the cardiovascular system, as well as larger vessels into which small vessels empty. The lymphatic system drains into large veins at the base of the neck, enabling lipids to be transferred from he small intestine to the blood.

Dehydration reaction

A reaction in which two molecules are covalently bonded to each other, with the loss of a water molecule, forming polymers.

In vitro mutagenesis

A technique used to discover the function of a gene by cloning it, introducing specific changes into the cloned gene's sequence, reinserting the mutated gene into a cell, and studying the phenotype of the mutant.

Wind Patterns

Air flowing close to Earth's surface creates predictable global wind patterns. As Earth rotates on its axis, land near the equator moves faster than that at the poles, deflecting the winds from the vertical paths shown above and creating more easterly and westerly flows. Cooling trade winds blow from east to west in the tropics; prevailing westerlies blow from west to east in the temperate zones, defined as the regions between the Tropic of Cancer and the Arctic Circle and between the Tropic of Capricorn and the Antarctic Circle.

Dominant allele

An allele that is fully expressed in the phenotype of a heterozygote

Euryhaline

Animals which can survive large fluctuations in external osmolarity (Barnacles/mussels)

What is hermaphroditism an answer to?

Animals with very limited opportunity to find a mate.

Passive immunization

Antibodies from immune animal injected into nonimmune animal

Monoclonal antibodies

Any of a preparation of antibodies that bave been produced by a single clone of cultured cells and thus are all specific for the same epitope.

Homeotic Genes

Any of the master regulatory genes that control placement and spatial organization of body parts in animals, plants, and fungi by controlling the developmental fate of groups of cells.

Outer ear

Consists of the external pinna and the auditory canal, which collects sound waves and channels them to the tympanic membrane (eardrum).

How does DNA methylation affect gene regulation?

DNA methylation, usually to the cytosine base in most plants, animals, and fungi, means the gene is not expressed. Removal of these methyl groups can turn on some genes. Methylation also accounts for genomic imprinting in mammals, where methylation permanently regulates expression of either the maternal or paternal allele of particular genes at the start of development. Once methylated, genes usually stay that way through successive cell divisions. At DNA sites where one strand is already methylated, enzymes methylate the correct daughter strand after each round of DNA replication.

How does sexual selection drive sympatric speciation?

Example: Cichlid. Mate choice based on male breeding coloration is the main reproductive barrier that normally keeps the gene pools of these two species separate.

Eye Anatomy

Eyelids, Conjunctiva, tear ducts and lysozymes, sclera, cornea, iris, lens, vitreous humor, retina, choroid, sclera.

Primary growth

Growth in length. Allows roots to extend throughout the soil and shoots to increase their eposure to lite. In herbaceous (nonwoody) plants, primary growth produces all, or almost all, of the plant body. Arises directly from apical meristems. produces epidermis, ground tissue, and vascular tissue. During each growing season, primary growth extends shoots

Note long-term changes in climate patterns on Earth as Ice Ages ended 16k years BP AND how trees re-colonized land that has been covered with ice. Problem for beech trees?

In areas that used to have glacial cover densely compacted the clay beneath the earth's surface, meaning the roots cannot take a deep hold into the ground.

How do rods/cones work?

In the dark, rods and cones are depolarized and continually release the neurotransmitter glutamate at these synapses. When light strikes the rods and cones, they hyper polarize, shutting off their release of glutamate. In response, the bipolar cells that are depolarized by glutamate hyper polarize, and those that are hyper polarized by glutamate depolarize. Information that passes from bipolar to ganglion cells, or horizontal cells carry signals from one rod or cone to other photoreceptors and to several bipolar cells.

Demography

The study of the vital statistics of populations and how they change over time.

Effector forms of B cells

Plasma cells, which secrete antibodies.

How did the Earth become Oxygenic?

O2 produced during water splitting step of photosynthesis. O2 dissolved in the surrounding water until it reached high enough concentration. Once high enough, it reacted with elements in the water, like iron, which precipitated as iron oxide, which accumulated as sediments. Once all the dissolved iron had precipitated, additional O2 dissolved in the water until the seas and lakes became saturated with O2. After this occurred, the O2 finally began to "gas out" of the water and into the atmosphere.

Describe neuron communication in chemical synapse?

Release of chemical neurotransmitter by the presynaptic neuron. At each terminal, the presynaptic neuron synthesizes the neurotransmitter and packages it in multiple membrane-enclosed compartments called synaptic vessels. The arrival of an action potential at a synaptic terminal depolarizes the plasma membrane, opening voltage-gated channels that allow Ca2+ to diffuse into the terminal. The resulting rise in Ca2+ concentration in the terminal causes some of the synaptic vesicles to fuse with the terminal membrane, releasing the neurotransmitter. Once released, the neurotransmitter diffuses across the synaptic cleft, the gap that separates the cells. Upon reaching the postsynaptic membrane, the neurotransmitter binds to and activates a specific receptor in the membrane.

Topoisomerase

Relieves overwinding strain ahead of replication forks by breaking, swiveling, and rejoining DNA strands

Vestigial structures

Remnants of features that served a function in the organism's ancestors. Ex. Some snakes retain vestiges of the pelvis and leg bones of walking ancestors.

Iteroparity

Repeated reproduction; Organism reproduces repeatedly over a long lifespan. Advantageous in a more stable, predictably survivable environment. Ex. Oak tree or tortoise, humans.

Ribose

The sugar to which the nitrogenous base is attached in RNA.

Simple Leaf Shape

Single, undivided blade. Some simple leaves are deeply lobed.

Single Nucleotide Polymorphism (SNP)

Single-base pair site where variation is found in at least 1% of the population. Most SNPs are noncoding, and don't contribute directly to the disease in question by altering the encoded protein.

What are the two components of species diversity?

Species richness and relative abundance

Keystone Species

Species that aren't usually abundant in a community, but exert strong control on community structure by their pivotal ecological niches Ex. In rocky intertidal communities of western North America, the relatively uncommon sea star Pisaster ochraceus preys on mussels such as Mytilus californianus, a dominant species and strong competitor for space. In the absence of Pisaster, species richness declined as mussels monopolized the rock face and eliminated most other invertebrates and algae. In a control area where Pisaster was not removed, species richness changed very little.

Taiga

Species-poor forests of conifers such as hemlock, fir, price, pine found in areas too cold for deciduous trees. Largest terrestrial biome on earth.

Temperate Broadleaf forests

Species-rich with fertile soil with lots of humus. Ex. Oak/hickory/maple/chestnut forest of eastern N. America. Distinct vertical layers: closed canopy, one or two strata of understory trees, a shrub layer, and an herb layer.

Internal fertilization

Sperm are deposited in or near the female reproductive tract. Adaptation that enables sperm to reach an egg even when the environment is dry.

Capsule

Sporangium; uses materials from the foot to produce spores by meiosis.

Describe Spermatogenesis

Stem cells that give rise to sperm are situated near the outer edge of the seminiferous tubules. Their progeny move inward as they pass through the spermatocyte and spermatid stages, and sperm are released into the lumen (fluid filled cavity) of the tubule. The sperm travel along the tubule into the epididymus, where they become motile. The stem cells arise from division and differentiation of primordial germ cells in the embryonic testes. In mature testes, the divide mitotically to form spermatogonia, which in turn generates spermatocytes by mitosis. Each spermatocyte gives rise to four spermatids through meiosis, reducing the chromosome umber from diploid to haploid. Spermatids undergo extensive changes in differentiating into sperm.

Skeletal Muscle

Striated Muscle; Responsible for voluntary movements. Consists of bundles of long cells called muscle fibers. Form by fusion of many cells, hence multiple nuclei in each fiber. Contractile units, sarcomeres, along the fibers gives the cells a striated appearance.

Hexose

Sugars that have six carbons Ex. Glucose, fructose

Apical dominance

The closer and axillary bud is to an active apical bud, the more inhibited it is. This is because of chemical communication by plant hormones, when branching. If an animal eats the end of the shoot or if shading results in the light being more intense on the side of the shoot, the chemical communication underlying apical dominance is disrupted. As a result, the axillary buds break dormancy and start to grow. Released from dormancy, and axillary bud eventually gives rise to a lateral shoot, complete with its own apical bud, leaves, and axillary buds.

Problem solving

The cognitive activity of devising a method to proceed from one state to another in the face of real or apparent obstacles.

Describe Winter in lakes with winter ice cover

The coldest water in the lake (0° C) lies just below the surface ice; water becomes progressively warmer at deeper levels of the lake, typically 4° C at the bottom (most dense)

Renal pelvis

The funnel-shaped chamber that receives processed filtrate from the vertebrate kidney's collecting ducts and is drained by the ureter

Wild type

The phenotype for a character most commonly observed in natural populations. Symbolized by +

Pulmocutaneous circuit

The right side of the heart, delivers oxygen-poor blood to the capillary beds in the lungs and the skin, where there is a net movement of O2 into the blood and of CO2 out of the blood.

Pulmonary Circuit

The right side of the heart, delivers oxygen-poor blood to the capillary beds of in the lungs, where there is a net movement of O2 into the blood and of CO2 out of the blood.

Biogeography

The scientific study of the geographic distributions of species.

Ecology

The scientific study of the interactions between organisms and the environment.

Hypoosmotic

The solution that is more dilute, with a lower concentration of solutes in non-isoosmotic solutions. Water flows by osmosis from a hypoosmotic solution into a hyperosmotic one.

Hyperosmotic

The solution with the higher concentration of solutes in non-isoosmotic solutions. Water flows by osmosis from a hypoosmotic solution into a hyperosmotic solution

Genetic recombination

The splicing of DNA sequences together to produce new combinations. Occurs via Crossing over in Prohpase I of Meiosis or Independent Assortment if genes aren't linked. Phenotypical & genotypical.

Amplification

The strengthening of a sensory signal during transduction. Amplification that occurs in sensory receptor cells often requires signal transduction pathways involving second messengers.

RNA Interference (RNAi)

Uses synthetic double-stranded RNA molecules matching the sequence of a particular gene to trigger break-down of the gene's mRNA or to block its translation.

Cytotoxic T cell

Uses toxic proteins to kill cells infected by viruses or other intracellular pathogens before pathogens fully mature. Cytotoxic T cells require interaction with an antigen-presenting cell. Fragments of foreign proteins produced in infected host cells associeate with class I MHC molecules and are displayed on the cell surface, where they can be recognized by cytotoxic T cells. Cytotoxic T cells have an accessory protein that binds to the MHC molecule. This accessory protein, CD8, helps keep the two cells in contact while the cytotoxic T cell is activated. Secretion of proteins that disrupt membrane integrity and trigger cell death occurs once cell is activated.

Phosphorus Cycle

Weathering of rocks gradually adds PO₄³⁻ to soil; some leaches into groundwater and surface water and may eventually reach the sea. Phosphate taken up by producers and incorporated into biological molecules may be eaten by consumers. Phosphate is returned to soil or water by either decomposition of biomass or excretion by consumers. Because there are no significant phosphorus-containing gases, only relatively small amounts of phosphorus move through the atmosphere, usually in the forms of dust and sea spray.

Morphogen Gradient Hypothesis

When gradients of substances called morphogens establish an embryo's acid and other features of its form. Researchers found that bicoid mRNA was highly concentrated at the extreme anterior end of the mature egg. After the the egg fertilizes, the mRNA diffused from the anterior to the posterior, resulting in a protein gradient with the highest concentration at the anterior end.

Allee effect

When individuals may have a more difficult time surviving or reproducing if the population size is too small. Ex: A single plant may be damaged by excess wind if it stands alone.

Bacteriophages/phages

A virus that infects bacteria

population ecology

Analyzes factors that affect population size and how and why it changes through time

Glutamate

Amino acid that can act as a neurotransmitter. At neuromuscular junction in invertebrates.

6 billion

How many nucleotide pairs in a single human chromosome?

Do all genes evolve at the same rate?

No.

Carbohydrates

Sugars and polymers of sugars.

Blade

The flattened portion of a typical leaf

Synaptic terminal

The part of each axon branch that forms a synapse.

The ovary

The structure at the base of the carpel; contains one or more ovules.

Why is gene cloning useful?

To amplify a particular gene To produce a protein product

Theraputic cloning

When the main aim of cloning is to produce ES cells to treat disease.

Regulated changes

Circumstances when the set points and normal ranges for homeostasis change.

Ketose

(Ketone sugar); Sugar with carbonyl group within the carbon skeleton.

Three overlapping processes involved in the development of a multicellular organisms

Growth, morphogenesis, and cell differentiation

Regeneration

2nd Step in asexual reproduction in which lost body parts are regrown.

How many number of molecules produced by PCR after n cycles?

2ⁿ

Describe the size of the carbon skeleton in sugars?

3 to 7 carbons long.

Prod. Eff. of microorganisms/insects

40% or more

Ganglia

A cluster (functional group) of nerve cell bodies

Cohort

A group of individuals of the same age

Angiotensin II

A peptide hormone that stimulates constriction of pre capillary arterioles and increases reabsorption of NaCl and water by the proximal tubules of the kidney, increasing blood pressure and volume.

Lignin

A relatively indigestible strengthening polymer that accounts for more than a quarter of the dry mass of wood. Lignin is present in all vascular plants but not in bryophytes.

Growth ring

A ring that appear in cross sections of most tree trunks because there is a marked contrast between the large cells of the new early wood and the smaller cells oft he late wood of the previous growing season.

Codons

A three nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code. Written 5>3, forms the nontemplate/coding strand

Malpighian tubules

Aa unique excretory organ of insects that empties into the digestive tract, removes nitrogenous wastes from he hemolymph, and functions in osmoregulation.

Classical conditioning

Ability of an animal to connect an arbitrary stimulus with a peasant or an aversive reward. Ex: Pavlov's dogs

How do Histone modifications regulate gene expression?

Acetylation of N-Terminus of histone tails leads to spreading out of chromatin due to neutralization of positive charges on histone R groups so that histone tails don't bind to nearby nucleosomes, resulting in 10 nm fibers and not 30 nm fibers - promotes transcription Acetylation enzymes may also bind and recruit transcription factors Methylation of histones can lead to chromatin condensation and thus less transcription

Why doesn't myoD differentiate all kinds of cells?

Activation of the muscle-specific genes is not solely dependent on MyoD but requires a particular combination of regulatory proteins, some of which are lacking in cells that do not respond to MyoD.

Locomotion

Active travel from place to place.

Stabilizing Selection

Acts against both extreme phenotypes and favors intermediate variants. This mode of selection reduces variation and tends to maintain the status quo for a particular phenotypic character.

Insertion

Addition of nucleotide pairs in a gene

How do nucleotides link into a polynucleotide?

Adjacent nucleotides are joined by a phosphodiester linkage, which consists of a phosphate group that links the sugars of two nucleotides after a dehydration reaction. The bonding results in a repeating pattern of sugar-phosphate units called the sugar phosphate backbone.

Adult Stem cells

Adult stem cells are pluripotent, and not able to give rise to all cell types in the organism, though they can generate multiple.

Compatibility Test in fungal sexual reproduction

After release of pheromones, if the mycelia ar of different mating types, the pheromones from each partner bind to receptors on the other, and the hyphae extend toward the source of the pheromones. Why the hyphae meet, they fuse. In species with such a "compatibility test," this process contributes to genetic variation by preventing hyphae from fusing with other hyphae from the same mycelium or another genetically identical one.

Systemic Circuit

After the oxygen-enriched blood leaves the gas exchange tissues, it enters the other pump, the left side of ht heart. Contraction of the heart propels this blood to capillary beds in organs and tissues throughout the body. Deoxygenated blood returns to the heart to complete the circuit.

Gene pool

All copies of every type of allele at every locus in all members of the population.

Global Change

Alters the fabric of Earth's ecosystems at regional to global scales. Includes alterations in climate, atmospheric chemistry, and broad ecological systems that reduce the capacity of Earth to sustain life. Ex. Acid Rain (pH less than 5.2), Burning of wood/ffuels releases oxides of sulfur and nitrogen that react with water to form sulfuric and nitric acids in the air.

Parasitic Fungi

Alters the landscape of the NE US Ex. Chestnut Blight. Produced hyphae within the cracks of the bark of American chestnut trees. Produce compounds toxic to humans Ex. Rye ergot, aflatoxins in grains and nuts, LSD. Parasitize animals (mycosis)

Coral Reefs

Among the most productive of the biomes, very important for fish populations, threatened by global warming and ocean acidification

calorie (cal)

Amount of heat it takes to raise the temperature of 1g of water by 1° C. The amount of heat that 1g of water releases when it cools by 1°C. 4.184 J.

What two types of modification is the transduction of stimuli by sensory receptors subject to?

Amplification and adaptation

Volume

Amplitude of the sound wave

Polygenic Inheritance

An additive effect of two or more genes on a single phenotypic character Example: At least 180 genes affect height

Glycerol

An alcohol found on fats with each of its three carbons containing a hydroxyl group.

What does an allele that causes a genetic disorder do?

An allele that causes a genetic disorder codes for either a malfunctioning protein or no protein at all.

Molecular Clock

An approach for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates. An assumption underlying this is that the number of nucleotide substitutions in orthologous genes is proportional to the time that has elapsed since the genes branched from their common ancestor. In the case of paralogous genes, the number of substitutions is proportional to the time since the ancestral gene was duplicated.

Acetylcholinesterase

An enzyme in the synaptic cleft that hydrolyzes the neurotransmitter acetylcholine.

Effective population

An estimate of the size of a population based on the numbers of females and males that successfully breed; generally smaller than the total population.

Cephalization

An evolutionary trend toward a clustering of sensory neurons and interneurons at the anterior (front) end of the body

Phenotype

An organism's appearance or observable traits - the physical expression of an organism's alleles; the body that is produced by the genes interacting with the environment.

Immune system

An organism's system of defenses against agents that cause disease

Homoplasies

Analogous structures: Same function- different ancestor.

Proteomics

Analysis of large sets of proteins, including their sequences.

Chargaff

Analyzed the base composition of DNA from one species to another, devising that the base composition of DNA varies between species, and for each species, the percentage of Adenine and Thymine bases are equal, while Guanine and Cytosine bases are also equal.

What do the properties of organic molecules depend on?

Arrangement of carbon skeleton and the chemical groups attached to that skeleton.

How do chitin-rich walls enhance feeding by absorption?

As a fungus absorbs nutrients from its environment, the concentrations of those nutrients in its cells increases, causing water to move into the cells by osmosis. The movement of water into fungal cells creates pressure that could cause them to burst if not surrounded by a rigid cell wall.

Primary Producers

Autotrophs. First Trophic level. Most are photosynthetic organisms that synthesize sugars and other organic compounds, which they use as fuel for cellular respiration and as building material for growth. Most common autotrophs: plants, algae, photosynthetic prokaryotes. Chemosynthetic prokaryotes (deep-sea hydrothermal vents and deep underground or in ice)

Basal Metabolic Rate

BMR: Animals must maintain a minimum metabolic rate for basic functions such as cell maintenance. The minimum metabolic rate of a non growing endotherm that is at rest, on an empty stomach, and is not experiencing stress. Measured under a comfortable temperature range.

Why is ice's lower density to water biologically significant?

Because it is less dense, ice will float atop water. This surface ice forms an insulating layer that drastically slows further cooling of the body of water. Ice also provides a solid habitat for some animals, such as polar bears and seals.

Edges

Boundaries between ecosystems with it own set of physical conditions which differ from those on either side of it.

What's special about a myosin head?

Can bind ATP. Hydrolysis of bound ATP converts myosin to a high-energy form that binds to actin, forming a cross bridge. The myosin head then returns to its low energy form as it pulls the thin filament towards the center of the sarcomere. When a new molecule of ATP binds to the myosin head, the cross bridge is broken.

Arteries

Carry blood from the heart to organs throughout the body

Natural Killer Cells

Cellular Innate Defenses in vertebrates. Cicrulate throughout the body and detect the abnormal array of surface proteins characteristic of some virus-infected and cancerous cells. They release chemicals that lead to cell death, inhibiting further spread of the virus or cancer.

Streams and Rivers

Change dramatically in temperature, aeration, speed of flow, and species along their lengths. Because streams are colder, they retain more oxygen and are thus more oxygen rich.

Kinesis

Change in activity or tunrning rate in response to a stimulus Ex: Sowbugs move in low moisture but move much less in high moisture. Result: They accumulate in damp areas.

Change in population size over time equation

Change in population size = Births + Immigrants entering - deaths - Emigrants leaving population ∆N/∆t = B-D, or ∆N/∆t = rN

Middle ear

Consists of the tympanic membrane, malleus (hammer), incus (anvil), and stapes (stirrup). Vibrations of the tympanic membrane are transmitted by movement of the three bones to the oval window on the choclea's surface.

Pathogen

Disease causing microorganisms, viruses, viroids, or prions.

Tympanic membrane

Eardrum; Moving air that reaches the outer ear causes the tympanic membrane to vibrate.

Factors on Metabolic Rate?

Endotherm/ectotherm, age, sex, size, activity, temperature, nutrition, and stress.

Lysozyme

Enzyme that breaks down bacterial cell walls

Adaptive Evolution

Evolution that results in a better match between organisms and their environment

Where does non assimilated biomass go?

Feces

Nodes of Ranvier

Gaps in the myelin sheath where voltage-gated sodium channels are restricted to.

SRY - Sex Determining Region of Y

Gene on the Y chromosome required for the development of testes.

Pith

Ground tissue that is internal to the vascular tissue.

List 4 important polar covalent bonds

H-O, H-N, C=O, C=N.

How do plants interact with herbivores?

Herbivores can reduce a plant's reproductive success by eating its roots, leaves, or seeds. As a result, if an effective defense against herbivores originates in a group of plants, those plants may be favored by natural selection.

Angiosperms

Huge clade consisting of all flowering plants; their seeds develop inside chambers that originate within flowers. Nearly 90% of all living plant species are angiosperms.

Why do we need fats?

Hydrocarbon chains are rich in energy. 1g of fat stores more than twice as much energy as a gram of a polysaccharide, like starch. Animals must carry their energy stores with them, so having a more compact reservoir of fuel is advantageous. Subcutaneous fat cushions vital organs and insulates body, too.

What determines sex?

If sperm cell bearing Y chromosome fertilizes an egg, the baby will be male.

What determines the chemical nature of the polypeptide?

Kind and sequence of the side chains.

Major Histocompatibility Complex

MHC; The host protein that displays the antigen fragment on the cell's surface.

5 classifications of sensory receptors?

Mechanoreceptors, chemoreceptors, electromagnetic receptos, thermoreceptors, and pain receptors

Intersexual selection

Members of one sex choose mates on the basis of characteristics of the other sex.

Chromosome theory of inheritance

Mendelian genes have specific loci (positions) along chromosomes, and it is the chromosomes that undergo segregation and independent assortment. Developed by Sutton and Boveri

Budding

Mode of asexual reproduction in which individuals arise from outgrowths of existing ones.

Voltage-gated ion channels

Openings or closings when the membrane potential passes a particular level.

Atrial natriuretic Peptide

Opposes the RAAS. The walls of the atria of the heart release ANP in response to an increase in blood volume and pressure. ANP inhibits the release of renin from JGA, inhibits NaCl reabsorption by the collecting ducts, and reduces aldosterone release from the adrenal glands.

Blind spot?

Optic disc in the retina lacks photoreceptors.

Plateau phase

Outer third of the vagina becomes vasocongested. Inner two thirds slightly expands. Elevation of uterus. All forms a depression for receiving sperm in the back of the vagina. Breathing and heart rate ++.

Gills

Outfoldings of the body surface that are suspended in the water. Gills often have a total surface area much greater than that of the rest of the body's exterior.

Quaternary structure

Overall protein structure that results from the aggregation of two or more polypeptide subunits into one functional macromolecule. Example: Collagen, Hemoglobin (two α subunits and two β subunits).

Surfactant

Phospholipids and proteins produced by alveoli that coat the alveoli and reduce surface tension.

Lycophytes

Phylum that includes club mosses, spike mosses, and quillworts. Plants in this clade lack seeds, but have vascular tissue. Grow on tropical trees/temparate forest floors. Sporophytes: Upright stems, with many small leaves, and well as ground-hugging stems that produce dichotomously branching roots. In many club mosses and spike mosses, sporophytes are clustered into club-shaped cones (strobili) Club mosses: Homosporous Spike mosses/quillworts: Heterosporous.

Monilophytes

Phylum that includes ferns, horsetails, and whisk ferns and their relatives. Plants in this clade lack seeds, but have vascular tissue. Share a more recent common ancestor with seed plants than lycophytes.

Tissue-specific proteins

Proteins found only in a specific cell type and give the cell its characteristic structure and function.

Why is CC's color and patter different?

Random X chromosome inactivation, a normal occurrence during embryonic development, due to the formation of barr bodies could silence specific coloring/patterning genes at that location on the cat.

Triose

Sugars with 3 carbons

How do we generate diversity in antigen receptors? (Structure of Ig genes)

Receptor light chain is encoded by three gene segments: Variable, Joining segment, and Constant segment. V and J segments together encode the variable region of the receptor chain. C's segment encodes the constant region. 40 different V options. 5 different J segments, meaning pieces can be combined in 200 different ways.

Polypeptide backbone

Repeating sequence of amino and carboxyl groups bonded together. One end of the chain has a free amino group (N-Terminus), while the opposite end has a free carboxyl group (C-terminus).

Eudicots

The clade that categorizes the vast majority of dicot species (2/3 angiosperm species- 170k species). Includes legume family and rose family, oak, walnut, maple, willow, and birch.

Function of double fertilization in angiosperms?

Synchronizes the development of food storage in the seed with the development of the embryo.

Prop roots

The aerial, adventitious roots of maize are prop roots, so named because they support tall, top-heavy plants. All roots of a mature maize plant are adventurous whether they emerge above or below ground.

Why is gas exchange in water more demanding than in air?

The amount of O2 dissolved in a given volume of water is always less than in an equivalent volume of air. Furthermore, the warmer and saltier the water is, the less dissolved O2 it can hold.

Secondary Production

The amount of chemical energy in consumers' food that is converted to their own new biomass.

Cell-mediated immune response

The branch of adaptive immunity that involves the activation of cytotoxic T cells, which defend against infected cells.

Cochlea & Organ of Corti

The cochlea is a coiled, fluid filled chamber with two large canals- an upper vestibular canal, and a lower tympanic canal- separated by a smaller cochlear duct. Both canals are filled with fluid. On the floor of the cochlear duct, the basilar membrane, is the organ of Corti, which contains the mechanoreceptors of the ear, hair cells with hairs projecting into the cochlear duct. Many of the hairs are attached to the tectorial membrane, which hangs over the organ of court like an awning. Sound waves make the basilar membrane vibrate, which results in bending of the hairs and depolarization of the hair cells.

Secondary Structure

The coils (α helix) and folds (β pleated sheets) of segments of the protein's polypeptide. Hydrogen bonding between the repeating constituents of the polypeptide backbone. In that backbone, oxygen atoms have a partial negative charge, and hydrogen atoms attached to the nitrogens have a partial positive charge, forming hydrogen bonds between the atoms to create the most stable configuration of the backbone. The high number of hydrogen bonds formed support a particular shape for that particular protein.

Sensory Transduction

The conversion of a physical or chemical stimulus to a change in the membrane potential of a sensory receptor

What is trophic structure?

The feeding relationships between organisms

Name the 3 ordered series of body segments in fruit flies and other arthropods

The head, the thorax mid-body, and the abdomen.

Reproductive leaves

The leaves of some succulents produce adventitious platelets, which fall of the leaf and take root in the soil.

Observations of Evolution - Natural Selection in Response to introduced species.

The length of the beak of Soapberry bugs varies depending on the bugs' environment, because the seeds on which the bugs feed are found at different depths of different fruits. Balloon vine seeds are much deeper than golden rain tree fruit (introduced from Asia) seeds, and so the beak length of the soapberry bug has decreased with the disappearance of the balloon vine in Florida.

Euchromatin

The less condensed form of eukaryotic chromatin that is available for transcription

B cell

The lymphocytes that complete their development in the bone marrow and become effector cells for the humoral immune response.

Equilibrium potential

The magnitude of the membrane voltage at equilibrium for a particular ion.

Phase changes

The morphological changes that arise from these transitions in shoot apical meristem activity.

Cystic Fibrosis

The most common lethal genetic disease in the United States. 1/25 are carriers when of European descent. Chloride transport channels are defective or absent in the plasma membranes of children homozygous recessive for CF. The result is an abnormally high concentration of extracellular chloride, which causes the mucus that coats certain cells to become thicker and stickier than normal. The mucus builds up in the pancreas, lungs, digestive tract, and other organs, leading to multiple effects, including poor absorption of nutrients from the intestines, chronic bronchitis, and recurrent bacterial infections.

pH

The negative logarithm (base 10) of the hydrogen ion concentration. pH declines as [H⁺] increases. Lower than 7 is acidic, greater than 7 is basic. 7 is water. Each pH unit represents a tenfold difference in H⁺ and OH⁻ concentrations.

Abyssal Zone

The part of the oceans benthic zone between 2k and 6k meters deep.

Recombination frequency

The percentage of recombinant offspring

Addition rule

The probability that any one of two or more mutually exclusive events will occur is calculated by adding their individual probabilities.

Clonal Selection

The process by which an antigen selectively binds to and activates only those lymphocytes bearing receptors specific for the antigen. The selected lymphocytes proliferate and differentiate into a clone of effector cells and a clone of memory cells specific for the stimulating antigen.

Thermoregulation

The process by which animals maintain their body temperature within a normal range

How do you use a restriction enzyme to make a recombinant DNA plasmid?

The restriction enzyme recognizes a specific 4-8-base-pair sequence, the restriction site, present at one place in the plasmid. The enzyme makes staggered cuts in the sugar-phosphate backbones within this sequence, producing fragments with sticky ends. Foreign DNA fragments with complimentary sticky ends can base-pair with the plasmid sticky ends, so long as the sequence was cut by the same restriction enzyme; DNA ligase then seals the strands, and the ligated product is a recombinant plasmid.

Fission

The separation of a parent organism into two individuals of approximately equal size.

Solute

The substance that is dissolved

Fertilization

The union of sperma nd egg

Hydronium ion

The water molecule that gained the hydrogen ion (H₃O⁺)

Heat

Thermal energy in transfer from one body of matter to another

Sclera

Tough, white protein coat that blocks most incoming light

How do ncRNAs inactivate x-chromosomes in most female mammals, preventing xp of genes located on one of the X-chromosomes?

Transcripts of the XIST gene located on the chromosome to be inactivated bind back to and coat that chromosomes. This binding leads to condensation of the entire chromosome into heterochromatin.

Yeast

Unicellular fungus. Often inhabit moist environments, including plant sap and animal tissues, where there is a ready supply of soluble nutrients, such as sugars and amino acids.

Evidence for Evolution - Biogeography

Using understanding of evolution and continental drift allows us to predict where fossils of different groups of organisms might be found. Example: Horse's evolutionary tree suggests that the genus that includes present-day horses originated 5 million years ago in North America. At that time, N and S America were not yet connected, making it difficult for horses to travel between them. Thus, we can predict that the oldest horse fossils should be found only in North America, where they originated.

Inducible Operon

Usually off but can be stimulated when a specific small molecule interacts with a regulatory protein (ie. lac operon)

Consanguineous

"Same blood" - used in pedigrees to show inbred matings with a double line

Fragmentation

1st step in asexual reproduction in which the body is broken into several pieces.

Herbivory

A +/- interaction in which an organism eats parts of a plant or alga.

Positive Feedback

A control mechanism that amplifies rather than reduces the stimulus.

Negative Feedback

A control mechanism that reduces, or "damps," the stimulus.

Response

A physiological activity triggered by a change in a variable.

Urethra

A tube that releases urine from the mammalian body near the vagina in females and through the penis in males

Sickle Cell Disease

Affects 1/400 Africans. Substitution of a single amino acid in the hemoglobin protein of red blood cells; in homozygous recessive individuals, all hemoglobin is of the sickle cell (abnormal) variety. When the O2 content of an affected individual's blood is low, the sidle-cell hemoglobin proteins aggregate into long fibers that deform the red cells into a sickle shape. Sickled cells may clump and clog small blood vessels, leading to other symptoms throughout the body, including physical weakness, pain, organ damage, and even paralysis. The presence of one sickle-cell allele rarely affects the phenotype, making the sickle cell allele recessive to the normal allele

Alveoli

Air sacs clustered at the tips of the tiniest bronchioles. Lack cilia, making them highly susceptible to contamination. WBC's patrol, but can be overwhelmed.

Carophyte

Algae that are the closest relatives of land plants.

Signal

Any behavior that causes change in another animal's behavior (facial expression in humans)

How and why do plants store starch?

As granules within cellular structures known as plastids, which include chloroplasts. Synthesizing starch enables the plant to stockpile surplus glucose.

Explain the lateral line system.

As in our semicircular canals, receptors are formed from a cluster of hair cells whose hairs are embedded in a cupula. Water entering the lateral line system through numerous pores that make up the lateral line canal bends the cupula, leading to depolarization of the hair cells and production of action potentials. In this way, the fish perceives its movement through water or the direction and velocity of water currents flowing over its body. The lateral line system also detects water movements or vibrations generated by prey, predators, and other moving objects.

Why don't we attack ourselves?

As lymphocytes mature in the bone marrow or the thymus, their antigen receptors are tested for self-reactivity. B and T cells with receptors specific for the body's own molecules are destroyed by apoptosis. The remaining self-reactivve lymphocytes are typically rendered nonfunctional.

Where is gene expression commonly controlled? Why is the term gene expression often equated with transcription for both bacteria and eukaryotes?

At transcriptions; regulation at this stage often occurs in response to signals coming from outside the cell, such as hormones or other signaling molecules. For this reason, the term gene expression is often equated with transcription.

Nitrogen Reservoirs

Atmosphere is 78% free N gas (N2). Other reservoirs of inorganic and organic nitrogen compounds are soils and the sediments of lakes, rivers, and oceans; surface water and groundwater; and the biomass of living organisms.

Taxis

Automatic movement toward positive stimuli (food) or away from negative stimuli (Planaria away from bright light)

Atrioventricular Node

Autorhythmic cells located in the wall between the left and right atria, which are stimulated when impulses originating at the sa node reach them.

Buttress roots

Because of moist conditions in the tropics, root systems of many of the tallest trees are surprisingly shallow. Aerial roots that look like buttresses, such as seen in trees in Venezuela, give architectural support to the trunks of trees

Dorsal-Ventral

Belly-to-belly

Osteoblasts

Bone forming cells that deposit a matrix of collagen

Mircoevolution

Changes over time in allele frequencies in a population

Interspecific Interactions

Competition, predation, herbivory, symbiosis, and facilitation

Describe thicknesses of Chromatin Packing in Eukaryotic Chromosomes

DNA: 10nm Nucleosomes: 10nm 30 nm Fiber: 30 nm Looped domains: 300nm Chromatid: 700nm

Urea

Different nitrogenous waste. Low toxicity but more energy expensive to make. Product of a metabolic cycle that combines ammonia with CO2 in the liver.

Why is cellulose important to our diet, even if we can't digest it?

Eliminated with feces, along the way, the cellulose abrades the wall of the digestive tract and stimulates the lining to secrete mucus, which aids in the smooth passage of food through the tract.

mtDNA...

Evolves rapidly and can be used to explore recent evolutionary events.

Mendel's second concept of heredity

For each character, an organism inherits two copies (that is, two alleles) of a gene, one from each parent.

Primary Consumers

Herbivores. Heterotrophs which depend directly or indirectly on the outputs of primary producers for their source of energy.

Cortical nephron

In mammals and birds, a nephron with a loop of Henle located almost entirely in the renal cortex. 85% of nephrons are cortical.

Limits on primary production in Aquatic Ecosystems

Light Limitation, utrient limitation

Sperm

Male gamete

What do normal cells lack that stem cells have? Why is this important

No active Telomerase causes normal cells to enter senescence and die when they reach the ends of their protective telomeres and genes begin to be deleted (Hayflick limit)

Sarcolemma

Plasma membrane of muscle cell; Holds Ligand-gated Na+ and K+ channels with receptors for ACh released by the neuromuscular synapse. Has voltage gated K+ and Na+ ion channels that allow a motor end-plate potential to travel along the cell membrane of the muscle cell. Transverse tubules (invaginations of the sarcolemma that extend through the muscle cell cytoplasm and sarcomeres) allow MEPPs to propagate through the cell to the sarcoplasmic reticulum next to each sarcomere. MEPPs cause sarcoplasmic reticulum to release Ca+2 ions into the sarcomere cytoplasm because the dihydropyridine receptors on the sarcoplasmic reticulum are voltage sensitive CA+2 channels and mechanically open Ryanodine receptor which are ALSO Ca+2 ion channels. Result: flow of Ca+2 ions from sarcoplasmic reticulum into sarcomere cystol when MEPP propagates down T tubules.

Micropyle

Pore in the integuments of the ovule, where two sperm cells are discharged into the female gametophyte during the angiosperm life cycle.

Chemoreceptor (specific receptors)

Receptor that responds to individual kinds of molecules

Ecological succession

Replacement of terrestrial communities by other species, which are then replaced by other species, etc.

Is the trp operon repressible or inducible? Why?

Repressible because its transcription is usually on but can be inhibited (repressed) when a specific small molecule binds allosterically to a regulatory protein.

How does the environment/induction influence cell differentiation in embryonic development?

Signals impinging on an embryonic cell from other embryonic cells in the vicinity, including contact with cell-surface molecules on neighboring cells. Such cells cause changes in target cells. The molecules conveying these signals within the target cell are cell-surface receptors and other signaling pathway proteins. In general, the ginning molecules send a cell down a specific developmental path by causing changes in its gene expression that eventually result in observable cellular change.

How effective has parental and fetal screening for Tay Sachs alleles?

Since the 1980, number of children born with this incurable disease has reduced by 90%

Spliceosome

Small nuclear snRNA of about 150 nukes that forms complexes called snRNP's. Several snRNP's then combine to form a spliceosome. This compel binds to several short nucleotide sequences along an intron, including the key sequences on each end. The intron is then released, and the spliceosome joins together two eons that flanked the intron.

Microphylls

Small, often spine-shaped leaves supported by a single strand of vascular tissue.

Why does habitat fragmentation lead to species loss?

Smaller populations have a higher probability of local extinction due to lower genetic variation.

Filament

Stalk structure on stamens

What are the three types of isomers?

Structural, cis-trans, and enantiomers

Paleontology

Study of fossils

Pleiotropy

The ability of a single gene to have multiple effects on phenotype

T Cells

The class of lymphocytes that mature in the thymus; they include both effector cells for the cell-mediated immune response and helper cells required for both branches of adaptive immunity.

Aestherosclerosis

The hardening of the arteries by accumulation of fatty deposits.

Surface Tension

The measure of how difficult it is to stretch or break the surface of a liquid.

Why is the epithelium lining the major branches of the respiratory tree lined with cilia and mucus?

The mucus traps dust, pollen ,and other particulate contaminants, and the beating cilia move the mucus upward to the pharynx, where it can be stalled into the esophagus.

Fundamental Niche

The niche potentially occupied by a species

Photosynthates

The sugars and the other carbohydrates produced during photosynthesis

P generation

The true-breeding parents

Plasmogamy

The union of two cytoplasms of two parent mycelia. In most fungi, the haploid nuclei contributed by each parent do not fuse right away. Instead, parts of the fused mycelium contain coexisting, genetically different nuclei.

Root hairs

Thin, finger-like extensions of root epidermal cells. Increase SA enormously. Found near the tips of elongating roots.

Define and list the acidic amino acids.

Those with side chains that are generally negative due to the presence of a carboxyl group on the side chain that is usually ionized at cellular pH. Aspartic acid, glutamic acid. Hydrophilic

When is arterial blood pressure highest?

When the heart contracts during ventricular systole.

Instantaneous population growth

dN/dt = r(inst)N

Hydroxyl group

(-OH); Alcohol; polar due to electronegative oxygen. Forms hydrogen bonds with water, helping dissolve compounds such as sugars. Example: Ethanol

Phosphate group

(-OPO₃²⁻); Organic phosphate; Contributes negative charge (1-when positioned inside a chain of phosphates; 2-when at the end). When attached, it confers on a molecule the ability to react with water, releasing energy. Example: Glycerol phosphate

Sulfhydryl Group

(-SH); Thiol; Two SH groups can react, forming a "cross-link" that helps stabilize protein structure. Hair protein cross-links maintain the straightness of curliness of hair. Example: Cyteine

Carbonyl group

(>C=O); Ketone (carbonyl group is within a carbon skeleton. Sugars with ketone groups are called ketoses) or Aldehyde (carbonyl group is at the end of a carbon skeleton. Sugars with aldehydes are called aldoses). Example of a Ketone: Acetone Example of an Aldehyde: Propanal

Aldose

(Aldehyde sugar); Sugar with carbonyl group at the end of the carbon skeleton.

Chaperonins

(Chaperone proteins) that assist in the proper folding of other proteins. Does not specify the final structure of a polypeptide. Keeps the new polypeptide segregated from disruptive chemical conditions in the cytoplasmic environment while it fold spontaneously. Water is present, ensuring a hydrophilic environment that aids the folding process. Secondary to sometimes quaternary structure.

Mammalian circulation

1. Contraction of the right ventricle pumps blood into the lungs via the pulmonary arteries. 2. As blood flows through capillary beds in the left and right lungs, it loads O2 and unloads CO2. 3. Oxygen rich blood returns from the lungs via the pulmonary veins to the left atrium of the heart. 4. Oxygen rich blood flows into the heart's left ventricle, which pumps the oxygen rich blood out to body tissues through the systemic circuit. Blood leaves the ventricle via the aorta, which conveys blood to arteries leading throughout the body. 5. Capillary beds in the head and arms, and capillary beds in the abdominal organs and legs, are supplied with oxygen rich blood as the aorta descends. 6. Capillaries rejoin, forming venules and veins. Oxygen poor blood from the head, neck, and forelimbs is channeled into a large vein, the superior vena cava. 7. Another large vein, the inferior vena cava, drains blood from the trunk and hind limbs. 8. The two vena cavae empty their blood into the right atrium, from which the oxygen poor blood flows into the right ventricle.

What are the functions of the poly-A tail and 5' cap?

1. Facilitate the export of the mature mRNA from the nucleus 2. Help protect the mRNA from degradation by hydrolytic enzymes 3. Help ribosomes attach to the 5' end of the mRNA once the mRNA reaches the cytoplasm.

Describe initiation in transcription

1. RNA polymerase binds to a promoter region on DNA. This promoter region includes ignition site where transcription begins and regions such as the TATA box in Eukaryotic cells help identify binding sites on DNA for RNA polymerase. Prok. cells only need RNA pol for transcription, while Euk's have RNA pol I for most rRNA, RNA pol II for mRNA and snRNA, and RNA pol III for tRNA. Euk polymerases must ALSO have various transcription factor proteins that help RNA pol bind to the promoter and form a transcription initiation complex. 2. RNA pol separates the 2 strands of the DNA double helix and transcribes the sequence of bases ONLY on the TEMPLATE strand. The NONTEMPLATE strand serves to stabilize the DNA double helix as a template in replication.

Describe elongation in transcription

1. The RNA Pol II moves along the DNA template strand, pairs the correct new RNA nucleotide with the complementary base on the DNA template strand (from 5' > 3') by splitting off 2 phosphates from the nucleoside triphosphate. 2. Rate: 40 RNA nukes/sec. Only 10-20 RNA nukes are bound to DNA bases at any instant 3. As the RNA pol progresses, the finished RNA molecule breaks from the coding strand and the 2 DNA strands zip back up as the H bonds between the bases reform

List 3 key observations about life

1. The striking ways in which organisms are suited for life in their environments 2. The many shared characteristics (unity) of life 3. The rich diversity of life

Describe the synthesis of DNA

1. Topoisomerase unwinds the DNA (using ATP) 2. Helicase separates the 2 original strands by breaking the H bonds between partner bases (more ATP) 3. Single-strand DNA binding proteins prevent re-formation of H-bonds between partner bases 4. RNA polymerase (Primase) builds an RNA primer (5-10 nucleotides long) at the origin for the leading strand and at various points opposite for the lagging strand 5. DNA polymerase III binds to the original DNA strand and (a) pairs the correct new deoxyribonucleoside triphosphate with its complementary partner base on the template strand. Also (b) splits pyrophosphate (2 joined phosphates) off the new nucleoside triphosphate and attaches the last phosphate to the 3' end of the previous nucleotide or RNA primer, if at the start. Lastly it (c) moves along the template DNA strand 1 nucleotide at a time from 3'>5', adding new nucleotides to form an antiparallel strand until it reaches the RNA primer of the next origin, or Okazaki fragment. 6. DNA pol I binds to the RNA primers at origins and at Okazaki fragments at the start of lagging strands and removes RNA nucleotides from 5 to 3, and replaces them with DNA nucleotides, attaching each new DNA nuke. 7. Ligase joins pieces of lagging strand and leading strand to form one continuous strand 8. topoisomerase twists DNA back up into 2 complete DNA molecules, each with one original strand and one new strand at any point on the DNA molecule.

When a caterpillar feeds on a leaf, how much is used for secondary production/growth?

1/6

How many control elements compose each enhancer, on average?

10 control elements which each can bind to only one or two specific transcription factors.

Prod. Eff. of fish

10%

kilocalorie (kcal)

1000 cal; the quantity of heat required to raise the temperature of 1 kilogram of water by 1°C

How many maternal genes are responsible for pattern formation in embryo during development?

1200

Who was Frederick Sanger?

1940s: Broke polypeptides at specific places in the hormone insulin, then used chemical methods to determine the amino acid sequence.

Production efficiency for caterpillar

33%

Major milestones in land plant evolution

475 mya: Plants colonize land (w/ help from mycorrhizal fungi) - bryophytes 425 mya: Origin of first vascular plants (seedless) - pteridophytes 305 mya: Origin of seeds (package of embryo, stored nutrients, and protective seed coat all in mobile unit) - gymnosperms By 140 mya origin of flowering plants where developing seeds are protected inside ovaries - angiosperms

How do ectotherms acclimatize?

@ cellular level. Cells may produce variants of enzymes that have the same function but different optimal temperatures. Proportions of saturated/unsaturated lipids in membranes change. Some produce ectotherms produce antifreeze proteins to prevent ice formation in their cells.

Predation

A +/- interaction between species in which one species, the predator, kills and eats the other, the prey.

Parasitism

A +/- symbiotic interaction in which one organism, the parasite, derives its nourishment from another organism, the host, which is harmed in the process.

Interspecific Competition

A -/- interaction that occurs when individuals of different species compete for a resource that limits their growth and survival.

Cloning vector

A DNA molecule that can carry foreign DNA into a host cell and replicate there.

Restriction fragments

A DNA segment that results from the cutting of DNA by a restriction enzyme.

Pathogen

A bacterium, fungus, virus, or other disease-causing agent

Mate choice copying

A behavior in which individuals in a population copy the mate choice of others. Example: Female guppies.

Polytomy

A branch point from which more than two descendant groups emerge.

Rooted

A branch point within the tree (farthest to the left) represents the most recent common ancestor of all taxa in the tree.

How does blood clot?

A break in a blood vessel wall exposes proteins that attract platelets and initiate coagulation. The coagulant circulates in an inactive form called fibrinogen. In response to a broken blood vessel, platelets release clotting factors that trigger reactions leading to the formation of thrombin, and enzyme that converts fibrinogen to fibrin. Thrombin also activates a factor that catalyzes the formation of more thrombin, driving clotting to completion.

Electroporation

A brief electrical pulse applied to a solution containing cells to create temporary holes in their plasma membranes, through which DNA can enter.

Asymmetric carbon

A carbon that is attached to four different atoms or groups of atoms.

Silent Mutation

A change in a nucleotide pair that transforms one codon into another that is translated into the same amino acid, and has no observable effect on the phenotype.

Mutation

A change in the nucleotide sequence of an organism's DNA.

Aneupoloidy

A chromosomal aberration in which one or more chromosomes are present in extra copies or a deficient in number

Inversion (chromosomes)

A chromosomal fragment may also reattach to the original chromosome but in the reverse orientation

Single Circulation

A circulatory system consisting of a single pump and circuit, in which blood passes from the sites of gas exchange to the rest of the body before returning to the heart.

Double Circulation

A circulatory system consisting of separate pulmonary and systemic circuits, in which blood passes through the heart after completing each circuit.

Expression vector

A cloning vector that contains a highly active bacterial promoter just upstream of a restriction site where the eukaryotic gene can be inserted in the correct reading frame. The bacterial host cell will recognize the promoter and proceed to express the foreign gene now linked to that promoter.

Cardiovascular System

A closed circulatory system with a heart and branching network of arteries, capillaries, and veins. Characteristic of vertebrates.

Acetycholine

A common neurotransmitter in both invertebrates and vertebrates at neuromuscular junction. Functions: Muscle stimulation, memory formation, learning. Two classes of acetylcholine receptor: ligand-gated ion channel.

Cloaca

A common opening for the digestive, urinary, and reproductive tracts found in many non mammalian vertebrates but in few mammals

Countercurrent multiplier systems

A countercurrent system in which energy is expended in active transport to facilitate exchange of materials and generate concentration gradients

Extinction Vortex

A cycle in which a small population is pushed to a smaller and smaller population size until no individuals survive as a result of inbreeding and genetic drift, combined with loss of genetic variation. Ex. Deforestation created little pockets of muruqui with little Gene diversity, meaning they have little defense against yellow fever.

Vascular cambium

A cylinder of meristematic cells only one cell thick. Adds layer of vascular tissue called secondary xylem (wood) and secondary phloem. Located outside the pith and primary xylem and to the inside of the primary phloem and the cortex. Forms exterior to the primary xylem and interior to the primary phloem and pericycle.

Excitatory Postsynaptic Potential (EPSP)

A depolarization that brings membrane potential toward threshold. Caused when ligand-gated ion channels are permeable to both K+ and N+, depolarizing toward a value that is fought midway between Ek and ENa.

Pedigree

A diagram of a family tree with conventional symbols, showing the occurrence of heritable characters in parents and offspring over multiple generations, allowing us to calculate the probability a future child will have a particular genotype/phenotype

Sexual dimorphism

A difference in secondary sexual characteristics between males and females of the same species due to sexual selection.

Lagging strand

A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5>3 direction away from the replication fork.

Anhydrobiosis

A dormant state involving loss of almost all body water. Seen in tardigrades. Requires adaptations that keep cell membranes intact. Desiccated individuals contain large amounts of sugars. A disaccharide called rehalose seems to protect the cells by replacing the water that is normally associated with proteins and membrane lipids.

Ureter

A duct leading from the kidney to the urinary bladder

Pus

A fluid rich in WBC's, dead pathogens, and cell debris from damaged tissue due to enhanced blood flow to the site of injury helping to deliver antimicrobial peptides.

How do we determine where genes are expressed by in situ analysis?

A fly embryo is incubated in a solution containing probes for five-different mRNAs, each probe labeled with a different fluorescent tag. The embryo was then viewed from the belly using fluorescent microscopy; Each color marks where a specific gene is expressed as mRNA.

How does a helper T cell activate adaptive immune responses?

A foreign molecule must be present that can bind specifically to the antigen receptor at the T cell. This antigen must be displayed on the surface of an antigen presenting cell. The antigen presenting cell can be a dendritic cell, macrophage, or B cell.

Sexual Selection

A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates

Sex linked gene

A gene located on either sex chromosome

Regulatory gene

A gene that codes for a (usually allosteric) protein, such as a repressor, that controls the transcription of another gene or group of genes. Regulatory genes are expressed continuously, although at a low rate, are located some distance from the original gene operon, and have their own promoters.

Egg polarity gene

A gene that helps control the orientation (polarity) of the egg; also called the maternal effect gene. One group of these genes sets up the ant-post axis of the embryo, while the second group establishes the dors-vent axis.

Population

A group of individuals of the same species living in an area. Members of a population rely on the same resources, are influenced by similar environmental factors, and are likely to interact and breed with one another.

Organ System

A group of organs that work together in performing vital body functions.

Community

A group of populations of different species in an area

Community

A group of populations of different species living close enough to interact

Describe function/form of sperm cell

A head containing the haploid nucleus is tipped with a special vesicle, the acrosome, which contains enzymes that help the sperm penetrate the egg. Behind the head, many mitochondria provide ATP for movement of the flagellar tail.

Quantitative Characters

A heritable feature that varies continuously over a range rather than in an either-or fashion Example: Human skin color/height

Renin-angiotensin-aldosterone System (RAAS)

A hormone cascade pathway that helps regulate blood pressure and volume. When blood pressure or volume drops, the JGA releases the enzyme renin. Renin initiates a series of steps tha cleave a plasma protein called angiotensinogen, ultimately yielding a peptide called angiotensin II. Angiotensin II raises blood pressure by constricting arterioles and stimulating the adrenal glands to release aldosterone.

Inhibitory Postsynaptic Potential (IPSP)

A hyper polarization that moves the membrane potential further from threshold. Caused when ligand-gated ion channels are selectively permeable for only K+ or Cl-.

Sporopollenin

A layer of durable polymer in charophytes/plants that prevents exposed zygotes from drying out. A similar chemical adaptation is found in the tough sporopollenin walls that encase plant spores.

Integument

A layer of sporophyte tissue that envelops and protects the megasporangium. Gymnosperm megasporangia are surrounded by one integument, whereas those in angiosperms usually have two integuments.

Huntington's disease

A lethal genetic disorder caused by a dominant allele that degenerates the nervous system. This allele has no phenotypic effect until the individual is about 35-45 years old. Once deterioration begins, it's fatal. A child born to a parent with Huntington's has a 50% chance of inheriting the allele and the disorder. Affects 1/10k people. Its late degenerative symptoms mean it is one of the more common dominant alleles that is passed on to offspring.

Solution

A liquid that is a completely homogenous mixture of two or more substances.

Polymer

A long molecule consisting of many similar or identical building blocks linked by covalent bonds.

Myofibrils

A longitudinal bundle of thin and thick filaments inside a muscle cell.

fruit

A mature ovary that thickens its wall as seeds develop from ovules after fertilization.

Net Ecosystem Production

A measure of the TOTAL BIOMASS ACCUMULATION over time. Net ecosystem production is defined as gross primary production minus the total respiration of all organisms in the system (Rt)- not just primary producers, but decomposers and other heterotrophs as well. NEP = GPP - Rt

Basal angiosperms

A member of one of three clades of early-diverging lineages of extant flowering plants. Consists of 3 lineages comprising only about 100 species. Includes water lilies.

Magnoliids

A member of the angiosperm clade that is most closely related to the combined eudicot and monocot clades. Consist of about 8k species (magnolias, laurels, and black pepper). Include both woody and herbaceous species. More closely related to eudicots than monocots.

Oval window

A membrane beneath the stapes that creates pressure waves in the fluid (perilymph) inside the cochlea.

DNA microarray assay

A method to detect and measure the expression of thousands of genes at one time. Tiny amounts of a large number of single-stranded DNA fragments representing different genes are fixed to a glass slide and tested for hybridization with samples of labelled cDNA.

Landscape/seascape

A mosaic of connected ecosystems

Peristalsis

A movement produced by rhythmic waves of muscle contractions passing from front to back.

Embryonic Lethal

A mutation with a phenotype leading to death of an embryo or larva.

Movement Corridor

A narrow strip or series of small clumps of habitat connecting otherwise isolated patches. Promote dispersal and reduce inbreeding in declining populations. Harmful because spreads disease.

Tracheal system

A network of air tubes that branch throughout the body. The largest tubes, called trachea, open to the outside. The finest branches extend close to the surface of nearly every cell, where gas is exchanged by diffusion across the moist epithelium that lines the tips of the tracheal branches. Larger insects meet their higher energy demands by ventilating their tracheal systems with rhythmic body movements that compress and expand the air tubes like bellows.

Companion cell

A nonconducting cell alongside each sieve-tube element, which is connected to the sieve tube element by numerous plasmodesmata. The nucleus and ribosomes of companion cells serve not only that cell itself but also the adjacent sieve tube element. In some plants, the companion cells in leaves also help load sugars into the sieve-tube elements, which then transport the sugars to other parts of the plant.

Batesian Mimicry

A palatable or harmless species mimics an unpalatable or harmful one. Ex. The larva of the hawkmoth Hemeroplanes ornatus puffs up its head and thorax when disturbed, looking like the head of a small venomous snake. in this case, the mimicry even involves behavior; the larva weaves its head back and forth and hisses like a snake.

Circadian Rhythm

A physiological cycle of about 24 hours that persists even in the absence of external cues. (Body temperature/melatonin production)

Torpor

A physiological state of decreased activity and metabolism, that enables animals to save energy while avoiding difficult and dangerous conditions.

Stem

A plant organ bearing leaves and buds. Serves to elongate and orient the shoot in a way that maximizes photosynthesis by the leaves. Also, elevates reproductive structures, thereby facilitating the dispersal of pollen and fruit.

Climograph

A plot of the annual mean temperature and precipitation in a particular region. Climograph is based on annual averages.

Hardy Weinberg Equilibrium

A population that is not evolving, meaning the allele and genotype frequencies remain constant from generation to generation

Eutrophication

A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria. Occurs because of sewage and fertilizer runoff from farms/lawns adds considerable nutrients to lakes, promoting the growth of primary producers. When the primary producers die, detritivores decompose them, depleting the water of much/all of its oxygen.

Induction

A process in which a group of cells or tissues influences the development of another group through close-range interactions. These signals come from growth-factors, self-surface molecules.

Horizontal Gene transfer

A process in which genes are transferred from one genome to another through mechanisms such as exchange of transposable elements and plasmids, viral infection, and perhaps fusions of organisms (Mediterranean house gecko.)

Bundle sheath

A protective layer of cells around each vein that regulates the movement of substances between the vascular tissue and the mesophyll of leaves. Bundle sheath cells are very prominent in leaves of species that carry out C4 photosynthesis.

Signal Recognition Particle

A protein RNA compel that recognizes a signal peptide as it emerges from a ribosome and helps direct that ribosome to the ER by binding to a receptor protein on the ER. There, the completed peptide will leave the ribosome and fold into its final conformation in the ER. Consists of 6 polypeptides and 1 mlc of 7SL RNA.

Antibody

A protein secreted by plasma cells (differentiated B cells) that bidns to a particular antigen; also called immunoglobulin. All antibodies have the same y-shaped structure and in their monomer form consist of two identical heavy chains and two identical light chains.

Activator

A protein that binds to DNA and stimulates transcription of a gene.

Phenylketonuria (PKU)

A recessively inherited disorder than occurs in about 1/10k-15k births in the US. Children with this disease cannot properly metabolic the amino acid phenylalanine. This compound and its by-product, phenylpyruvate, can accumulate to toxic levels in the blood, causing severe intellectual disability. If PKU is detected in the newborn, a special diet low in phenylalanine will usually allow normal development. Screening is detected at birth by simple biochemical tests.

Hybrid Zone

A region in which members of different species meet and mate, producing at least some offspring of mixed ancestry. Yellow bellied and fire bellied toads. Produce few viable offspring.

Explain the fly dance

A returning bee quickly becomes the center of attention for other bees, called followers. If food is close, the returning bee moves in tight circles while moving its abdomen from side to side. If food far, bee dance consists of a half-circle swing in one direction, a straight run during which the bee waggles its abdomen, and a half-circle swing in the other direction, communicates to the follower bees both the direction and distance of the food source relative to the hive. The angle of the straight run relative to the hive's vertical surface is the same as the horizontal angle formed by the location of the food relative to the sun.

Peristome

A ring of interlocking, tooth-like structures on the upper part of the capsule. These "teeth" open under dry conditions and close again when its moist, allowing moss spores to be discharged gradually, via periodic gusts of wind that can carry them long distance.

Sensory Receptor

A sensory cell or organ, as well as the sub cellular structure that detects stimuli.

Fixed action pattern

A sequence of unlearned behaviors that don't change and that proceed along to completion once triggered by a sign stimulus Ex: Graylag goos while sitting on eggs in nest will extend neck to use her bill to scoot an egg back into the nest that has been moved outside. Wayward egg = sign stimulus. Movements of the bill/neck are the FAP Proximate Cause:

Diaphragm

A sheet of skeletal muscle that forms the bottom wall of the cavity.

Graded potential

A shift in the membrane potential, with a magnitude that varies with the strength of the stimulus: larger stimulus = larger change in membrane potential

What is an advantage grouping genes of related function into one transcription?

A single "on-off switch" can control the whole cluster of functionally related genes; genes are coordinately controlled.

Inducer

A specific small molecule that binds to a bacterial repressor protein and changes the repressor's shape so that it cannot bind to an operator, thus switching an operon on.

Microspore

A spore from a heterosporous plant species that develops into a male gametophyte.

Geologic Record

A standard time scale that divides Earth's history into four eons and further subdivisions: Hadean, Archaean, and Proterozoic, which together lasted 4 billion years.

Testosterone

A steroid hormone required for development of the male reproductive system, spermatogenesis, and male secondary sex characteristics; the major androgen in mammals.

Aldosterone

A steroid hormone that acts on nephrons' distal tubules and collecting duct to reabsorb sodium and potassium ions.

Progesterone

A steroid hormone that prepares the uterus for pregnancy; the major progestin in mammals

Estradiol

A steroid hormone that stimulates the development and maintenance of the female reproductive system and secondary sex characteristics; the major estrogen in mammals.

Histamine

A substance released by mast cells that causes blood vessels to dilate and become more permeable in inflammatory and allergic responses.

Acid

A substance that increases the hydrogen ion concentration of a solution. Examples: Battery acid, Lemon juice, Vinegar, Coffee, Rainwater, Urine, Saliva

Buffer

A substance that minimizes changes in the concentrations of H⁺ and OH⁻ in a solution. Example: Carbonic acid (H₂CO₃), which is formed when CO₂ reacts with water in blood plasma, will dissociate into HCO₃⁻, a base, and a Hydrogen ion in order to counteract a rise in pH.

Base

A substance that reduces the hydrogen ion concentration of a solution. Can directly accept hydrogen ions, or dissociate to form hydroxide ions, which combine with hydrogen ions to form water. Examples: Human blood, tears, seawater, milk of magnesia, household ammonia, bleach, oven cleaner

Lichen

A symbiotic association between a photosynthetic microorganism and a fungus in which millions of photosynthetic cells are held in a mass of fungal hyphae. The photosynthetic partners are unicellular or filamentous green algae or cyanobacteria. The fungus usually gives lichens its overall shape and structure, and tissues formed by hyphae account for most of the lichen's mass. Fungus partner provides protection, water, minerals, nutrients, shade, gas exchange, and protective toxins. The cells of the alga or cyanobacteria generally occupy an inner layer below the lichen surface. The alga or cyanobacterium provides carbon compounds; a cyanobacterium also fixes nitrogen and provides organic nitrogen compounds. As might be expected of such "dual organisms," asexual reproduction as a symbiotic unit is common. This can occur either by fragmentation of the parental lichen or by the formation of soredia. The fungi of many lichens also reproduce sexually.

Culture

A system of information transfer through social learning or teaching that influences the behavior of individuals in a population.

Describe Elongation (translation)

A tRNA with the correct anticodon and AA binds to the A site (E in the form of 1 GTP is required for codon recognition.) A ribozyme on the large ribosomal subunit transfers the peptide chain from the tRNA on the Site to the AA on the A site, forming a peptide bond. The whole ribosomal complex now moves down the mRNA 1 codon so that the tRNA and codon that were on the A site are now on the P site, and the uncharged tRNA that was on the P site is now on the E site and leaves. E cost per translocation: 1 GTP. Direction from 5'>3' on mRNA

Gel Electrophoresis

A technique for separating nucleic acids or proteins on the basis of their size and electrical charge, both of which affect their rate of movement through an electric field in a gel made of agarose or another polymer.

Adventitious

A term describing a plant organ that grows from an unusual source, such as roots arising from stem or leaves.

Root cap

A thimble-like structure at the tip of a root that protects the delicate apical meristem as the root pushes through the abrasive soil. Also secretes a polysaccharide slime that lubricates the soil around the tip of the root. Growth occurs just behind the tip in three overlapping zones of cells at successive stages of primary growth.

Helper T Cell

A type of T cell that, when activated, secretes cytokines that promote the response of B cells and Cytotoxic T cells to antigens

Fibroblasts

A type of cell in loose connective tissue that secretes the protein ingredients of the extracellular fibers

How much do cells express of their protein-coding genes at one time?

A typical human cell expresses how much of its protein-coding genes at any given times

Operon

A unit of genetic function found in bacteria and phages, consisting of an operator, promoter, and a coordinately regulated cluster of genes whose products function in a common pathway.

Allele

A version of a gene; for the ABO blood type there are 3 alleles: I^A, I^B, and i

Adaptive Immunity

A vertebrate-specific defense that is mediated by B lymphocytes and T lymphocytes and that exhibits specificity, memory, and self-nonself recognition.

Hydrogen Bond

A weak attraction between a partial positive charge on one molecule (or part of a molecule) and a partial negative charge on another molecule (or part of a molecule). These partial charges arise when polar covalent bonds form between highly electronegative atoms and much less electronegative atoms. Bond energy = 5 kilo cal per mol

What is a B cell antigen receptor made of?

A y shaped molecule consisting of four polypeptide chains: 2 heavy chains and 3 light chains, with disulfide bridges linking the chains together

Replication fork

A y-shaped region where the parental strands of DNA are being unwound

Post processing of RNA in Eukaryotes

Addition of 5' cap of a modified G base to the 5' end after transcription of the first 20-40 nucleotides. At the 3' end, an enyme adds 50-250 more A nukes, forming a poly A tail. Conversion of pre-mRNA to mRNA requires removal of intervening sequences and splicing together of expressed sequences.

What lets water travel up plants' roots?

Adhesion of water by hydrogen bonds to molecules with lots of partial charges, (such as cellulose in cell walls), allow water to travel up the walls of the vessels..

Adult Stem Cells vs. ES cells

Adult stem cells cannot give rise to all cell types in the organism, though they can generate multiple types (pluripotent). With the right culture conditions, cultured stem cells from adult animals have been made to differentiate into multiple types of specialized cells, although not as versatile as ES cells. Adult SC are easier to get, and using specific cells from the donor means the cells are less likely to be rejected. Only way to obtain ES cells thus far has been to harvest them from human embryos, which raises political/ethical issues. Totipotent.

How do activators/repressors influence transcription indirectly?

Affecting chromatin structure. Som activators recruit proteins that acetylate histones near the promoters of specific genes, thus promoting transcription. Some repressors recruit proteins that remove acetyl groups from histones, leading to reduced transcription, a phenomenon referred to as silencing. Recruitment of chromatin-modifying proteins seems to be the most common mechanism of repression in eukaryotes.

What prevents pressure waves from reverberating within the ear and causing prolonged sensation?

After propagating thought the vestibular canal, pressure waves pass around the apex of the cochlea and dissipate as they strike the round window. This damping of sound waves resets the apparatus for the next vibrations that arrive.

Sugar-Conducting Cells of the phloem

Alive at functioning maturity. In seedless vascular plants and gymnosperms, sugars and other organic nutrients are transported through long, narrow cells called sieve cells. The the phloem of angiosperms, these nutrients are transported through sieve tubes, which consists of sieve-tube elements

What would happen if ice sank as it formed?

All bodies of water would eventually freeze solid, making life as we know it impossible on Earth. In summer, only the upper few inches of the ocean would thaw.

What do chemical groups do to the solubility of organic compounds in water?

All except the sulfhydryl are hydrophilic, and thus increase the solubility of organic compounds in water.

Deuteromycetes

All fungi lacking sexual reproduction.

Describe the structure of visual pigments and how they work

All have same basic structure: A retinal molecule bound to an opsin molecule; retinal is derived from vitamin A and opsin is a protein. Retinal has a chain of alternating single and double Carbon-Carbon bonds When retinal absorbs light, it changes from its C5-C6 CIS configuration to its all-TRANS configuration... in a few hundred femtoseconds; in the process the attached rhodopsin changes shape and activates transducin, a G protein that travels in the plane of the disk membrane and activates phosphodiesterase that cleaves cGMP from the Na+ channels of the plasma membrane The Na+ channels then close, preventing the Na+ ions from entering the cell and causing the cell to hyper polarize and thus to release less glutamate. This signal transduction amplifies the activation of a single rhodopsin by 300-400k times.

Species area curve

All other factors being equal, the larger the geographic area of a community, the more species it has, in part because larger areas offer a greater diversity of habitats and microhabitats. S = cA^z. S is number os species found in a habitat. C is a constant. A is the area of the habitat. Z tells you how many more species should be found in a habitat as its area increases.

Motor Unite

All the muscle cells (fibers0innervated by a single motor neuron. The activity of any motor unit is all or nothing, but more or fewer motor units may be activated and the frequency of AP'S on the motor unit may increase or decrease and larger or smaller motor units may be activated. Muscle spindles monitor stretching of muscle.

What is the biological significance of buffers?

Allows biological fluids to maintain a relatively constant pH despite the addition of acids or bases. Ex. pH stability in human blood

What is the biological significance of cohesion?

Allows water columns to be pulled to the tops of trees and keep leaves alive.

How do females comply with dosage theory?

Almost all of one X chromosome in each cell in female mammals becomes inactivated during early embryonic development. As a result, the cells of females and males have the same effective dose (one copy) of most X-linked genes. The inactive X in each cell condenses into a compact object called a Barr body, which lies along the inside of the nuclear envelope. Most of the Genes of the x-chromosome that forms the Barr body are not expressed. In the ovaries, however, Barr-body chromosomes are reactivated in the cells that give rise to eggs, such that following meiosis, every female gamete has an active X.

Pneumatophores

Also known as air roots, pneumatophores are produced by trees such as mangroves that inhabit tidal swamps. By projecting above the water's surface at low tide, they enable the root system to obtain oxygen, which is lacking in the thick, waterlogged mud.

Framshifte

Alteration in the reading frame of the genetic message due to an insertion or deletion of nucleotides, occurring whenever the number of nukes inserted or deleted is not a multiple of 3.

What traits do all land plants share?

Alternation of generations; multicellular dependent embryos; walled spores produced in sporangia; multicellular gametangia; apical meristems

Mendel's first concept of heredity

Alternative versions of genes account for variations in inherited characters.

Hamilton's rule

Altriusm is favored when teh benefit oto the recipient and coefficient of relatedness (fraction of genes that are share) are high and the cost to the actor is relatively low. rB>C

Disturbance

An event, such as a storm, fire, flood, drought, or human activity, that changes a community by removing organisms from it or altering resource availability. Storms disturb almost all communities, even those in the oceans through waves. Fire is a significant disturbance, and so grassland biomes require regular burning to maintain their structure and species composition. A high level of disturbance is generally the result of frequent and intense disturbance.

Heterochrony

An evolutionary change in the rate or timing of developmental events. As a result, the adult form is altered substantially. (Gorilla vs. Human skull, finger rate to wings in bats, slow leg growth in whales)

Genetic Profile

An individual's unique set of genetic markers, detected most often today by PCR, or, previously, by electrophoresis and nucleic acid probes.

Commensalism

An interaction between species that benefits one of the species but neither harms nor helps the other (+/0) Ex. Cowbirds and cattle egrets feed on sects flushed out of the grass by grazing bison, cattle, horses, and other herbivores. Because the birds increase their feeding rates when following the herbivores, they clearly benefit from the association. The bison/cattle, however, may sometimes benefit as well" the birds occasionally remove and eat ticks and other ectoparasites from the herbivores or may warn them of a predator.

Growth

An irreversible increase in size

Character

An observable heritable feature that varies among individuals

Recombinant types; Recombinants

An offspring whose phenotype differs from that of the true-breeding P generation parents.

Parental types

An offspring with a phenotype that matches one of the true-breeding P generation phenotypes; also refers to the phenotype itself.

Primary oocyte

An oocyte prior to completion of meiosis I.

Secondary oocyte

An oocyte that has completed meiosis I.

Transgenic animal

Animal in which a gene from an animal (often of a different species) of one genotype is introduced into the genome of the first animal.

Conformer

Animal that allows its internal condition to change in accordance with external changes in the variable.

Regulator

Animal that uses internal mechanisms to control internal change in the face of external fluctuation of an environmental variable.

Ectothermic

Animals gain most of their heat from external sources. Many adjust their body temperature through behavioral means. Generally need to consume less food than endotherms.

Stenohaline

Animals that cannot tolerate substantial changes in external osmolarity.

Passive immunity

Antibodies in the recipient are produced by another individual. Because passive immunity does not involve the recipients B and T cells, it persists only as long as the transferred antibodies last.

How does an effective adaptive response develop?

Antigen is presented to a steady stream of lymphocytes in the lymph nodes. A match between antigen receptor and epitope initiates events that activate the lymphocyte bearing the receptor. Once activted, a B or T cell undergoes multiple divisions. For each activated cell, the result of this proliferation is a clone. Some cells from this clone become effector cells, while others become memory cells.

Explain the process of Antigen-presenting cell-helper T cell binding

Antigen receptors on the surface of the helper T cell bind to the antigen fragment and to the class II MHC molecule displaying that fragment on the antigen presenting cell. At the same time, an accessory proteiin called CD4 on the helper T cell surface binds to the Class II MHC molecule, helping keep the cells joined. As the two cells interact, signals in the form of cytokines are SECRETED FROM THE ANTIGEN PRESENTING CELL. THESE CYTOKINES, ALONG WITH CYTOKINES FROM THE HELPER T CELL ITSELF, ACTIVATE THE HLEPER T cell and stimulate its proliferation. Cell proliferation produces a clone of activated helper t cells. All cells in the clone have receptors for the same antigen fragment complex with the same antigen speecificity. These cells secrete other cytokines, which help activate B cells and cytotoxic T cells.

How can pathogens avoid the immune system's defenses?

Antigenic variation (change epitopes via mutation. or Latency (viral genome persists in nuclei until conditions arise that are favorable for virla transmission or unfavorable for host survival.

State Mendel's law of Segregation

Any gamete can only get 1 allele from the parent. This is true because in Anaphase I of Meiosis, the homologous chromosomes that posses both parents' alleles for a gene are separated.

Antigen

Any substance that elicits a B or T cell response.

What is the evidence of differentiation?

Appearance of mRNAs for tissue-specific proteins. Observable changes in cell-structure.

Ecotone

Areas of intergradation between different biomes.

No summation

As a graded potential, a postsynaptic potential becomes smaller with distance from the synapse. Therefore, by the time a single EPSP reaches an axon hillock, it is usually to small to trigger an action potential.

Hydrophobic interaction.

As a polypeptide folds into its functional shape, amino acids with hydrophobic (nonpolar) side chains usually end up in clusters at the core of the protein, out of contact with water. Once nonpolar amino acid side chains are close together, van der Waals interactions help hold them together.

Describe Fall in lakes with winter ice cover'

As surface water cools rapidly, it sinks beneath the underlying layers, remixing the water until the surface begins to freeze and the winter temperature profile is reestablished.

When does folding of a protein normally occur?

As the protein is being synthesized in the crowded environment within a cell, aided by other proteins.

Ascending Loop of Henle

Ascending limb has a transport epithelium that lacks water channels. The epithelial membrane that faces the filtrate in the ascending limb is thus impermeable to water. Two segments (thick and thin). As filtrate ascends the thin segment, NaCl, which became concentrated in the descending limb, diffuses out of the permeable tubule into the interstitial fluid. This movement of NaCl out of the tubule helps maintain the osmolarity of the interstitial fluid in the medulla. In the thick segment, the movement of NaCl out of the filtrate continues. Here, however, the epithelium actively transport NaCl into the interstitial fluid. The result of losing salt but not water, the filtrate becomes more dilute as it moves up the cortex.

What's the problem with the biological species concept?

Asexual organisms don't qualify as species Makes it impossible to categorize fossils BSC is defined by absence of gene flow, but there are many pairs of species that are morphologically and cologically ditinct yet gene flow occurs between them.

Yeast Cell reproduction

Asexual reproduction in yeasts occurs by ordinary cell division or by the pinching off of small "bud cells" off a parent cell.

How is visual information processed int he brain?

Axons of ganglion cells form the optic nerves that transmit sensation from the eys to the brain. The two optic nerves meet at the optic chasm near the center of the base of the cerebral cortex. Axons are routed so sensations from the left visual field are transmitted to the right side of the brain, and vice versa. Within the brain, most ganglion cell axons lead to the LATERAL GENICULATE NUCLEI, which have axons that reach the PRIMARY VISUAL CORTEX in the cerebrum. Additional neurons carry the information to higher order visual processing and integrating centers elsewhere in the cortex.

How does mRNA degradation regulate gene xp?

Bacterial mRNA typically degrade within a few minutes of their synthesis. This shorts like span of mRNAs is one reason bacteria can change their patterns of protein synthesis so quickly in response to environmental changes. mRNAs in multicellular eukaryotes typically survive for hours, days, or even weeks. Nucleotide sequences that affect how long an mRNA remains are often found in the untranslated region (UTR) at the 3' end of the molecule.

What allows RNA to take on the particular three dimensional shape necessary for its function?

Base pairing within an RNA molecule.

Why does velocity lower as blood goes from arteries to capillaries?

Because of the sheer number of capillaries, the total cross sectional area is greater than that of arteries, resulting in a dramatic decrease in velocity.

Why are most new mutations on phenotypes usually harmful?

Because organisms reflect many generations of past selection, and hence their phenotypes tend to be well matched to their environment, most new mutations that alter a phenotype are at least slightly harmful.

How do homeotic proteins affect the formation and identity of whole animal structures?

Because the homeodomain is a DNA-binding domain that folds into a structure just like other developmental proteins, homeotic proteins also regulate genetic switches in animal development.

Describe osmoregulation in a marine fish

Because the ocean is a strongly dehydrating environment, these animals constantly lose water to their environment by osmosis. Such fishes gain water and salt ions from food and by drinking seawater. They also excrete salt ions from the gills and scanty urine from the kidneys, which also excrete small amounts of water. Finally, there is osmotic water loss through gills and other parts of body surface.

Imprinting

Behavior with both learned and innate parts that is irreversible and that occurs in a sensitive period in the young animal's life Ex: Young goslings will follow the first large object that moves and doesn't eat them after they hatch. Young songbirds learn the songs of their fathers while in the nest.

What is the role of Natural Selection in Adaptive evolution

Beneficial adaptations arise gradually over time as natural selection increases the frequencies of alleles that enhance survival and reproduction. As the proportion of individuals that have favorable traits increases, the match between a species and its environment improves (ie. adaptive evolution occurs)

Semelparity

Big-Bang reproduction; the organism accumulates resources for one huge reproductive event with lots of offspring; advantageous in erratic environments or environments in which survival of the young is low. Ex. Century plant or salmon

How do specific transcription factors that function as repressors inhibit gene xp?

Bind directly to control element DNA (in enhancers or elsewhere), blocking activator binding. Interfere with the activator itself so it can't bind the DNA.

How do enhancers regulate the rate of gene expression?

Binding of specific transcription factors, either activators or repressors, to the control elements of enhancers either increases or decreases gene xp.

Why does density change over time?

Births, deaths, emigration, immigration

Compound leaf shape

Blade consists of multiple leaflets. A leaflet has no axillary bud at its base. In some plants, each leaflet is further divide into smaller leaflets. Compound leaves may withstand strong wind with less tearing. They may also confine some pathogens that invade the leaf to a single leaflet, rather than allowing them to spread to the entire leaf.

When can stem cells be isolated from early embryos?

Blastula/blastocyst stage. These ES cells reproduce indefinitely, and depending on culture conditions can be made to differentiate into a wide variety of specialized cells.

Prezygotic Barriers

Block fertilization from occurring by impeding members of different species from attempting to mate, by preventing an attempted mating from being completed successfully, and by hindering fertilization if mating is completed successfully.

Closed circulatory system

Blood is confined to vessels and is distinct from interstitial fluid. One or more hearts pump blood into large vessels that branch into smaller ones that infiltrate the organs. Chemical exchange occurs between the blood and the interstitial fluid, as well as between the interstitial fluid and body cells. Benefits: Reltively high blood pressure, allowing delivery of O2 and nutrients to larger more active mammals.

What pulls fluid back into the capillaries?

Blood proteins and blood cells are too large to pass readily throughout the endothelium, and they remain in the capillaries. These dissolved proteins are responsible for much of the blood's osmotic pressure. The difference in osmotic pressure between he blood and the interstitial fluid opposes fluid movement out of the capillaries.

What is the biological significance of water's high specific heat?

Bodies of water change temperature slowly; the larger the body of water, the slower the temperature change. Thus, temperature changes are moderated by oceans, lakes, and for active animals releasing lots of metabolic heat.

Estuaries

Bodies of water with freshwater inflows and restricted opening to the sea so that freshwater and salt water mix with each tidal cycle; as nutrients are trapped by tidal cycles and flocculation (precipitation due to salt), primary productivity of marshes within these estuaries is HUGE.

Multicellular Fungi

Bodies typically form a network of tiny filaments called hyphae. Hyphae consist of tubular cell walls surrounding the plasma membrane and cytoplasm of the cells. Hyphal structure provides enormous SA/Vol ratis as the fungus grows through and digests its nutrient source. The cell walls are strengthened by chitin (strong/flexible polysaccharide).

Beadle and Tatum experiment

Bombarded bread mold with x-rays to create mutations in mold. Identified mutants that could not survive on minimal medium, apparently because they were unable to synthesize certain essential molecules from the minimal ingredients

Compare and contrast estradiol (type of estrogen) and testosterone?

Both are steroids and organic molecules with a common carbon skeleton in the form of four fused rings. They differ only in the chemical groups attached to the rings.

Sclereids

Boxier than fibers and irregular in shape, have very thick, lignified secondary walls. Impart the hardness to nutshells and seed coats and the gritty texture to pear fruits

Nervous system in vertebrates

Brain and spinal cord = CNS. Nerves and ganglia = PNS

Arterioles

Branched arteries within organ.

Lateral roots

Branches of the primary root that greatly enhance the ability of the root system to anchor the plant and to acquire resources such as water and minerals from the soil.

Phylogenetic Tree

Branching diagram that represents the evolutionary history of a group of organisms.

Role of lichens in primary/secondary succession

Break down the surface by physically penetrating and chemically attacking it, and they trap windblown soil. Nitrogen-fixing lichens also add organic nitrogen to some ecosystems. These processes make it possible for a succession of plants to grow.

Testcross

Breeding an organism o unknowns genotype with a recessive homozygous to reveal the genotype

Petals

Brightly colored structures interior to the sepals. Aid in attracting pollinators. Flowers that are wind-pollinated generally lack brightly colored parts.

Alfred Russel Wallace

British naturalist who developed a hypothesis of natural selection almost identical to Darwin's.

How do telomeres protect the ends of chromosomes?

Build with repeating base sequences - TTAGGG repeated 100-1000 times in humans. These telomeres both prevent the uneven ends of chromosomes from triggering apoptosis AND protect the genes near the ends of the chromosomes from being eroded by the shortening of the ends.

Lamarck's hypothesis

By comparing living species with fossil forms, Lamarck found what appeared to be several lines of descent, each a chronological series of older to younger fossils leading to a living species. His explanation was that of USE and DISUSE, the idea that parts of the body that are used extensively become larger and stronger, while those that are not deteriorate. His example was a giraffe's neck. His second principle was inheritance of acquired characteristics, stating an organisms could pass these modifications to its offspring. Also thought evolution occurs because organisms have an innate drive to become more complex.

After calcium is released into the cytosol of a muscle cell, how does the muscle contract?

Calcium ions bind to troponin complexes bound to the actin strands of thin filaments. In a muscle fiber at rest, tropomyosin covers the myosin binding sites along the thin filament, preventing actin and mysoin from interacting. When Ca+ accumulates in the cytosol, it binds to the troponin complex, causing tropomyosin bound along the actin strands to shift position and expose the myosin binding sites. Cycles of myosin cross bridge formation and breakdown, coupled with ATP hydrolysis, slide thin filament toward center of the sarcomere. Cystolic Ca2+ is removed by active transport into SR after action potential ends. Tropomyosin blockage of myosin-binding sites is restored.

Phylogenetic Bracketing

Can predict features shared by two groups of closely related organisms are present in their common ancestor and all of its descendants unless independent data indicate otherwise.

Cognition

Capacity of an animal's nervous system for perceiving, processing, storing, and retrieving and using sensory information

What are some adaptations of diving mammals?

Capacity to store large amounts of O2 in their bodies, due to twice the volume of blood per kilogram of body mass as human. High concentration of myoglobin in muscles, which can store oxygen. Swim with little muscular effort Heart rate -- during dives Blood is rerouted to the brain, spinal cord, eyes, adrenal glands, and, placenta (pregnant only) Derive ATP from fermentation instead of respiration. Diving reflex vasoconstriction

How does carbon's electron configuration help it create such diverse molecules?

Carbon only holds 4 valence electrons, meaning it can share up to 4 more electrons with other atoms to fill its valence shell, giving it high covalent compatibility with many different elements. This allows carbon to act as an intersection point from which a molecule can branch off in as many as four directions, creating large, complex molecules.

How does carbon help create diversity?

Carbon's ability to form four bonds can be used to build and inexhaustible variety of organic molecules. Different species or organisms, and even individuals within a species, are distinguished by variations in the types of organic molecules they make.

Platelets

Cell fragments that are involved int he clotting process. Pinched off cytoplasmic fragments of specialized bone marrow cells. No nuclei.

What is the biological significance of water not being able to dissolve non-polar molecules with which it can form not Hydrogen bonds?

Cell membranes consist of non-polar lipids that maintain structure and form a barrier between the concentrated, organized materials inside the cell and the chaotic, far less concentrated solution outside the cell.

Filtrate

Cell-free liquid extracted from the body fluid by the excretory system

What are the two levels of metabolic control?

Cells can adjust the activity of enzymes already present (this is fast response, and relies on sensitivity of enzymes to chemical cues that increase or decreases their catalytic activity). Example: Feedback inhibition Cells can adjust the production level of certain enzymes; they can regulate the expression of the genes encoding the enzymes.

What are the potential uses for iPS cells?

Cells from patients suffering from diseases can be reprogrammed to become iPS cells, which can act as model cells for studying the disease and potential treatments. Second, a patients own cells could be reprogrammed into iPS cells and then used to replace nonfunctional tissues such as insulin-producing cells of the pancreas.

Vascular tissue

Cells joined into tubes that transport water and nutrients throughout the plant body.

Cork Cells

Cells that accumulate to the exterior of the cork cambium that the cork cambium gives rise to. As cork cells mature, they deposit a suberin in their walls and then die.

Initials

Cells that remain as sources of new cells. Stem cells.

Why does the body reject certain blood types?

Certain bacteria normally present in the body have epitopes very similar to the A and B carbohydrates. Responding to the bacterial epitope similar to the b carbohydrate, a person with type A blood makes antibodies that will react with the B carb. The anti B antibodies in the type A blood cause an immediate and devastating trasnfusion reaction, casuing RBC's to lyse, and can lead to septic shock.

Ventricles

Chambers of the heart responsible for pumping blood out of the heart.

Atria

Chambers of the heart that receive blood.

How can fertilization affect allele frequencies?

Chance alone controls the egg and sperm pair and the resulting allele expressed with the corresponding genotype.

Catalyst

Chemical agents that selectively speed up chemical reactions without being consumed by the reaction. Used by enzymes to regulate metabolism.

Why is glucose's structure a ring and not linear?

Chemical equilibrium between the linear and ring structures greatly favors the formation of rings. When linear, carbon 1 bonds to the oxygen attached to carbon 5 to form a carboxyl when forming the glucose ring.

Functional group

Chemical group directly involved in chemical reactions.

Neurotransmitters

Chemical messengers that pass information from the transmitting neuron to the receiving cell

Pheromones

Chemical signals between members of the same species Ex: Female gypsy moths release pheromones that attract males from miles away or phereomones released by human males that human females use to detect MHC compatibility for mating.

What spurs coordinate control of dispersed genes in a eukaryotic call?

Chemical signals from outside of the cell. Molecules can control gene xp indirectly by triggering signal transduction pathways that lead to activation of particular transcription activators/repressors. Every gene whose transcription is stimulated by a particular signal, regardless of its chromosomal location, has a control element recognized by that hormone-receptor complex.

Pheromones

Chemicals released by one organism that can influence the physiology and behavior of other individuals of the same species. Small, volatile, or water-soluble molecules that disperse into the environment, like hormones, are active at very low concentration.

Deletion (chromosome structure error in meiosis)

Chromosomal fragment is lost, meaning the affected chromosome is then missing certain genes.

3 basic components of a circulatory system

Circulatory fluid, set of interconnecting vessels, and a heart (muscular pump)

What are the double bonds that usually occur in naturally occurring fatty acids?

Cis double bonds - cause a kink in the hydrocarbon chain wherever they occur.

Polyphyletic

Clad that includes distantly related species but does not include their most recent common ancestor.

Paraphyletic

Clade that consists of an ancestral species and some, but not all, of its descendants.

Trichomes

Class of highly specialized epidermal cells found in shoots. Hairlike trichomes reduce water loss and reflect excess light in some desert species. Some trichomes defend against insects though shapes that hinder movement or glands that secrete sticky fluids or toxic compounds.

Macroclimate

Climate patterns on the global, regional, and landscape level

Transcription initiation complex

Cluster of proteins that assembles on the promoter sequence at the "upstream" end of the gene. Includes RNA polymerase II.

What are the three kinds of connective tissue fibers?

Collagenous fibers, reticular fibers, and elastic fibers.

Cladistics

Common ancestry is the primary criterion used to classify organisms.

Chi-Square Test; X² Test

Compares an observed phenotypic ratio of F2 offspring with an expected ratio, which assumes the genes are unlinked, and measures the discrepancy between the two in order to find out if the genes are linked or not.

How do satellites "see" rates of photosynthesis in different regions of the globe?

Comparing the ratios of wavelengths reflected back to them. Vegetation reflects much more near-infrared radiation than visible radiation, producing a reflectance pattern very different from that of snow, clouds, soil, and liquid water.

Genomics

Comparing whole genomes of different species.

What is a CDR?

Complementarity determining regions. Clustered at one end of the beta barrel, these hyper variable loops in the variable domains of an immunoglobulin construct a surface for antigen-specific bonding. The residues in the CDR's vary from one antibody to the next, imparting antigen specificity to each antibody.

Annuals

Complete their life cycle, from germination to flowering seed production to death, in a single year or less. Many wildflowers, legumes, cereal grains.

Isomers

Compounds that have the same numbers of atoms of the same element but different structures and hence different properties, creating variation in the architecture of organic molecules.

Conifers

Con-bearing plants, such as pines, firs, and redwoods. "Naked" seed plants.

Linked Genes/ Linkage

Condition in which the same group of alleles is produced because the genes that code for them do NOT show independent assortment because they are so close to each other on a chromosome that cross-over events rarely occur between them. Proved by Morgan by mating homozygous wild type fruit flies with homozygous recessive and noting the predicted ratio of Wild type and recessive outnumbered the offspring that took one of each allele from both groups.

Eustachian tube

Connects the pharynx and equalizes pressure between the middle ear and the atmosphere.

Small pop. approach

Conservation Biologists who adopt the small-population approach study the various processes that cause extinctions once population sizes have been reduced.

White matter

Consists mainly of bundled axons. In the spinal cord, white matter makes up the outer layer, consistent with its functions in linking the CNS to sensory and motor neurons of the PNS. In the brain, white matter is predominantly in the interior, where signaling between neurons functions in learning, feeling emotions, processing sensory information, and generating commands.

Pseudostratified Columnar Epithelium

Consists of a single layer of cells varying in height and the position of the nuclei. Pseudostratified epithelium of ciliated cells forms a mucous membrane that lines portions of the respiratory tract. The beating cilia sweet the film of mucus along the surface.

Coniferophyta

Consists of about 600 species of conifers. Most have woody cones, but a few have fleshy cones. Some, such as pines, have needle-like leaves. Others (redwoods) have scale-like leaves. Some species dominate vast northern forests. Others native to southern hemisphere. Most are evergreens. When sprign comes, conifers already have fully developed leaves that can take advantage of the sunnier, warmer days.

Inner ear

Consists of fluid filled chambers, including the semicircular canals, and the cochlea.

How is blood flow in capillary beds altered?

Constriction or dilations of the arterioles that supply capillary beds. Precapllary sphincters, rings of smooth muscle located at the entrance of capillary beds, regulate and redirect the passage of blood into particular sets of capillaries. Signals regulating blood flow include nerve impulses, hormones, and chemicals produced locally.

Hemoglobin Structure

Contained in RBC's and has four subunits with a heme group that has an iron atom at its venter. Binds O2 reversible. When O2 binds to one subunit, the others change shape slightly, increasing affinity for O2. Also helps with unloading.

Cartilage

Contains collagenous fibers embedded in a rubbery protein-carbohydrate complex called chondroitin sulfate. Condrocytes secrete the collagen and chondroitin sulfate, which together make cartilage a strong yet flexible support material. Cartilage is replaced by bones in vertebrates, but remains in some locations (disks that act as cushions between vertebrae)

Parasympathetic division

Corresponds to calming responses and return to self-maintenance functions (heart rate --, digestion ++, glycogen production ++) Aids sympathetic division in regulating reproductive activity

Where are countercurrent multiplier systems found in human excretion?

Countercurrent system involving the loop of Henle expends energy to actively transport NaCl from the filtrate in the upper part of the ascending limb. This system maintains a high salt concentration in the interior of the kidney, enabling the kidney to form concentrated urine.

Glycosidic linkage

Covalent bond formed between two monosaccharides by a dehydration reaction.

Evolutionary ramifications of homologous genes

Create new forms of the similar structures across species when combined with different tools in the "genetic tool kit," such as different transcription factors, and signaling pathways, the way other genes are turned on or off in the course of development leads to different forms.

Septa

Cross walls in hyphae that have pores large enough to allow ribosomes, mitochondria, and even nuclei to flow from cell to cell.

Where is genetic diversity in moss life cycle?

Crossover, independent assortment, random fertilization

Meselson and Stahl's Experiment

Cultured bacteria in heavy nitrogen Isotope, then transferred it to a medium with a lighter isotope. A sample was take after the first DNA replication; another sample was taken after the second replication. Extracted DNA from the bacteria in the samples, and then centrifuged each DNA sample to separate DNA of different densities. The first replication produced a band of hybrid DNA. The second produced both light and hybrid.

Estrous cycles

Cycles in other mammals in which in the absence of pregnancy, the uterus reabsorbs the endometrium and no extensive fluid flow occurs. Mammals with estrous cycles usually copulate only during the period surrounding ovulation.

Give an example of a structural isomer

C₅H₁₂ has 3 forms, C₈H₁₈ has 18 variants, C₂₀H₄₂ has 366,319 possible variants.

Example of Biological Magnification

DDT (chemical used to control insects such as mosquitoes and agricultural pests). After WWII, the use of DDT grew rapidly; its ecological consequence were not yet fully understood. By 1950's, scientists were learning that DDT persists in the environment and is transported by water to areas far from where its applied. One of the first signs that DDT was a serious problem was a decline in the populations of pelicans, ospreys, and eagles, birds that feed at the top of food webs. The accumulation of DDT in the tissues of these birds interfered with the deposition of calcium in their eggshells. When the birds tried to incubate their eggs, the weight of the parents broke the shells of affected eggs, resulting in catastrophic declines in the birds' reproduction rates.

Hierarchical Classification

DKPCOFGS. Drunk Kings Pay4 Cars Offices, Food, Games, and Sex.

Identify the two types of structural domains that are commonly found in a large number of activator proteins

DNA-binding domain: A part of the protein's 3d structure that binds to DNA. Activation domain: Binds other regulatory proteins or components of the transcription machinery, facilitating a series of protein-protein interactions that result in enhanced transcription of a given gene. Transcription factors can have one or more of either type of domain.

Natural Selection

Darwin's explanation of how adaptations arrive in a populace; a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Detritus

Dead organic matter. A motor source of food for many benthic species. Rains down from the productive surface waters of the photic zone.

Active immunity Immunization

Dead/weak virus

Fungal Ecological Roles

Decomposers, Mutualistic symbionts, parasites,

Detritivores

Decomposers; Consumers that get their energy from detritus.

α Helix

Delicate coil held together by hydrogen bonding between every fourth amino acid.

What are the demands of the smaller animal's higher metabolic rate per gram?

Demands a higher rate of oxygen delivery. To meet this demand, the smaller animal must have a higher breathing rate, blood volume (relative to size), and heart rate.

Fibrous connective tissue

Dense with collagenous fibers. Found in tendons and ligaments

K- Selection

Density Dependent Selection; Selection for life history traits that keep a population stable near its carrying capacity. Selection for traits that are sensitive to population density and are favored by high-densities. Ex. Iteroparity and the production of few, large offspring over long intervals. Ex. Humans or elephants

Evolution

Descent with modification

Hydrophobic

Describes any substance which repels water. Ex. Oil.

Hydrophilic

Describes any substance with an affinity to water. Ex. Cotton is hydrophilic but too big to dissolve in water.

Thermoreceptors

Detect heat and cold.

Nirenberg

Determined the mRNA codon UUU specified phenylalanine

DNA Sequencing

Determining the complete nucleotide sequence of a gene or DNA segment.

Georges Cuvier

Developed paleontology by studying strata near Paris. Noted that the older the strata, the more dissimilar its fossils were to current life-forms. Opposed evolution. Speculated that the different fossils found between strata layers represented a sudden catastrophic event that destroyed many of the species living in that area, allowing new ones to immigrate

Carolus Linnaeus contributions to science world

Developed two part (binomial) format for naming species "for the greater glory of God." Grouped similar species into increasingly general categories, such as genus and family

Cuboidal Epithelium

Dice-shaped cells specialized for secretion. Found in kidney tubules, thyroid, and salivary glands

Genetic Variation

Differences among individuals in the composition of their genes or other DNA sequences.

How does alternative RNA splicing regulate gene xp?

Different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as eons and which as introns. Regulatory proteins specific to a cell type control intron-exon choices by binding to regulatory sequences within the primary transcript.

What did cloning the carrot teach us?

Differentiated cells from the root were incubated in culture medium to grow into a full, genetically identical plant. Differentiation does no necessarily involve irreversible changes in the DNA. In plants, at least, mature cells can "dedifferentiate" and then give rise to all the specialized cell types of the organisms. Any cell with this potential is said to be totipotent.

Why does the body reject tissue/organ transplants?

Differing MHC molecules can act as antigens, stimulating an immune response that leads to rejection.

What creates variation in the antigen binding site?

Differneces in the amino acid sequences of variable regions provide the variation in binding surfaces that enables this highly specific binding.

Sporocytes

Diploid cells, or spore mother cells, that undergo meiosis and generate the haploid spores.

Morphological species concept

Distinguishes a species by body shape and other structural features. The morphological species concept can be applied to asexual and sexual organisms. Disadvantage is that is relies on subjective criteria, as researchers might disagree on which structural features distinguish a species.

Enteric Division

Division in the Autonomic nervous system of the PNS that is active in digestive tract, pancreas, and gallbladder.

Erythropoietin

EPO; Hormone secreted by kidneys that stimulates the generation of more erythrocytes.

What is common about Tinman, Distal-less, and Pax-6 families of proteins?

Each contains a homeodomain, and thus are all DNA-binding proteins.

Explain "either-or" phenotypic differences

Each organism either has 1 phenotypic trait or another. Characters that vary in this way are typically determined by a single gene locus, with different alleles producing distinct phenotypes.

Life cycle of a pine

Each tree has both ovulate and pollen cones (2n) Micropsorocytes divide by meiosis,producing haploid microspore. A microspore develops into pollen grain. (2n) + MEIOSIS ~or~ An ovulate cone scale has two ovules, each containing a megasporangium. (2n) Pollination occurs when a pollen grain reaches the ovule. The pollen grain germinates, forming a pollen tube that slowly digests its way through the megasporangium (2n) + MEIOSIS While the pollen tube develops, the megasporocyte undergoes meiosis producing four haploid cells. One survives as a megaspore (n) The megaspore develops into a female gametophyte that contains two or three archegonia, each of which will form an egg. (n) By the time theggs are mature, sperm cells have developed in the pollen tube, which extends to the female gametophyte. Fertilization occurs when sperm and egg nuclei unite. (n) FERTILIZATION Fertilization usually occurs more than a year after pollination. All eggs may be fertilized, but usually only one zygote develops into an embryo. The ovule becomes a seed, consisting of an embryo, food supply, and seed coat. (2n)

When does pattern formation begin?

Early embryo, when the major axes of an animal are established.

Latitudinal Variation in Sunlight Intensity

Earth's curved shape causes latitudinal variation in the intensity of sunlight. Because sunlight strikes the tropics most directly, more heat and light per unit of surface area are delivered there.

Secondary Succession

Ecological succession when an existing community has been cleared by some disturbance that leaves the soil intact, as in Yellowstone following the 1988 fires. Following the disturbance, the area may return to something like its original state.

What are the two strongest predictors of a falling birth rate?

Education for girls and career opportunities for them.

Autonomic Nervous system

Efferent component of the PNS that regulates smooth and cardiac muscles. Made up of sympathetic, parasympathetic, and enteric, which together control the organs of the digestive, cardiovascular, excretory, and endocrine systems.

Nutrient Enrichment (ie. Fertilizer runoff)

Effluent from farms, sewage, pig parlors, livestock operations that is enriched in N and/or P ends up in rivers/ponds/lakes and allows an algal/cyanobacterial bloom. When these organisms run out of nutrients and die, the decomposing bacteria remove dissolved O2, creating a dead zone of low O2 levels and fish die

Cytoplasmic Determinants

Egg's cytoplasm contains both RNA and proteins encoded by the mother's DNA. Since the cytoplasm of an unfertilized egg is not homogenous, messenger RNA, proteins, other substances, and organelles are distributed unevenly in the unfertilized egg. This unevenness is maintained because said determinants are bound to the cytoskeleton within a cell.

How do scientists introduce recombinant DNA into eukaryotic cells?

Electroporation, vectors, and injecting the DNA directly into single eukaryotic cells using microscopically thin needles.

How do large biological molecules exhibit unique emergent properties.

Emergent properties arise from the orderly arrangement of their atoms, like with water and simple organic molecules.

Radiation

Emission of electromagnetic waves by all objects warmer than absolute zero

Ecosystem ecology

Emphasizes energy flow and chemical cycling between organisms and the environment.

Ecosystem Services

Encompasses all the processes through which natural ecosystems help sustain human life. Ecosystems purify water/air. Detoxify/decompose wastes, reduce impacts of flooding/extreme weather. Pollinate crops, control pests, and create/preserve soils.

Structure of capillary

Endothelium and surrounding extracellular layer, the basal lamina.

What are the limiting factors of the logistic Growth model?

Energy, shelter, refuge from predators, nutrient availability, water, and suitable nesting sites.

Name all of the types of proteins

Enzymatic, defensive, storage, transport, hormonal, receptor, contractile and motor, structural

B galactosidase

Enzyme that breaks down lactose into glucose and galactose

Transacetylase

Enzyme that helps break down galactose

Inducible enzymes

Enzymes whose synthesis is induced by a chemical signal. Usually function in catabolic pathways, which break down nutrients to simpler molecules. By producing the appropriate enzymes only when the nutrient is available, the cell voids wasting energy and precursors making proteins that are not needed. (Example, allolactase induces enzymes in lactose pathway)

Shannon diversity (H)

Equation to determine diversity of a community. H = -(Pa lnPa + Pb lnPb + Pc lnPc...) A, B, C... are the species in the community. "P" is the relative abundance of each species.

Island equilibrium model

Equilibrium will eventually be reached where the rate of species immigration equals the rate of species extinction. The number of species at this equilibrium point is correlated with the island's size and distance from the mainland. Small islands generally have lower immigration rates than large ones. Also have higher extinction rates because they generally contain fewer resources, have less diverse habitats, and have smaller population sizes.

Carrying capacity of Earth

Estimates range from less than 1 billion to more than 1 trillion

What is the name for more spread-out DNA strands that are accessible to transcription enzymes?

Euchromatin

Heterochromatin

Eukaryotic chromatin that remains highly compacted during Interphase and is generally not transcribed.

Heterochromatin

Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed

How can regulation occur after translation?

Eukaryotic polypeptides must be processed to yield function proteins, being cleaved or undergoing chemical modifications. Regulatory proteins are commonly activated or inactivated by the reversible addition of (P)- groups or sugars. In addition, some proteins must be transported to target destinations in the cell in order to function. Regulation may occur at any of these steps. OR Cell can attach molecules of ubiquitin to functional proteins for selective degradation. Giant protein complexes called proteasome then recognize the ubiquitin-tagged proteins and degrade them.

Game theory

Evaluates alternative strategies in situations where the outcome depends on the strategies of all the individuals involved. Ex: Polymorphism in side-blotched lizard. Orange > yellow > blue throat

The Water Cycle

Evaporation of liquid by solar energy, Condensation of water vapor into clouds Precipitation. Transpiration by terrestrial plants also moves large volumes of water into the atmosphere. Surface and groundwater flow returns water to the oceans, completing the water cycle. The oceans contain 97% of the water in the biosphere. Approximately 2% is bound in glaciers and polar ice caps, and the remaining 1% is in lakes, rivers, and groundwater.

2nd Law of Thermodynamics + Implication

Every exchange of energy increases the entropy of the universe. Therefore, energy conversions are vastly inefficient. Some energy is always lost as head. Thus, energy doesn't cycle within an ecosystem, like matter does- instead it flows through it, and constantly needs to be replenished by the sun.

What factors go into what kind of nitrogenous waste an animal excretes?

Evolutionary history, habitat, immediate environment of egg (shells only permeable to gasses), Energy budget

DNA that codes for rRNA ....

Evolves slowly to investigate relationships over hundreds of millions of years old

Global ecology

Examines how the regional exchange of energy and materials influences the functioning and distribution of organisms across the biosphere.

Landscape ecology

Examines the factors controlling exchanges of energy, materials, and organisms across multiple ecosystems.

Four phases of the reseal response

Excitement, plateau, orgasm, resolution

Metanephridia

Excretory organs that collect fluid directly from the coelom.

Threats to plant diversity

Exploding population Deforestation Loss of plants >> loss of insects >> loss of other rainforest animals.

Arbuscular Mycorrihizal Fungi

Extend branching hyphae through the root cell wall and into tubes formed by invagination of the root cell plasma membrane.

Axon

Extension that transmits signals to other cells. Much longer than dendrites.

Zoned Reserve

Extensive region that includes areas relatively undisturbed by humans surrounded by areas that have been changed by human activity adn are used for economic gain.

Aneuploidy of X chromosomes?

Extra copies simply become inactivated as Barr bodies

Pax-6

Eyeless, aniridia, and Small eye genes; "master regulatory gene" for eye development. Found to be in animals with all sorts of eyes, from simple structures such as those in flatworms to the much more complex eyes of vertebrates.

Ocelli

Eyespots in planarians that receive light only through an opening where there are no pigmented cells. By comparing the rate of AP's coming from the two ocelli, the planarian is able to move away from a light source until it reaches a shaded location.

Vascular tissue system

Facilitate the transport of materials through the plant and provides mechanical support

Density Dependent factors

Factors that influence the birth or death rate as population density increases: Competition for resources Disease rates Territory availability Predation Toxic Wastes: Dense pops. produce wastes which limit further pop. growth. Ex: Yeast and alcohol, humans and CO2, or sewage Intrinsic Factors: Stress responses to crowded conditions that trigger aggression/hormonal changes

Nondisjunction

Failure of homologous chromosomes to separate during meiosis I or of sister chromatids to separate during Meiosis II, resulting in monosomy or trisomy

What do hydrocarbons have to do with fats?

Fats have 3 long hydrocarbon tails attached to a non hydrocarbon component.

Kidney function in the Vampire Bat

Feeds at night on the blood of large birds and mammals. Uses sharp teeth to make a small incision in the prey's skin and then laps up blood from the wound. Anticoagulants in the saliva prevent the blood from clotting. Searches for hours to find prey. When it does, it consumes as much blood as possible (sometimes .5 bodyweight). Bat thus is at risk of becoming too heavy to fly. As it feeds, however, the bat's kidneys excrete large volumes of dilute urine, up to 24% of body mass per hour, allowing bat to lose enough weight to fly. Most of the nutrition vampire bats derive from blood comes in the form of protein. Digesting proteins generates large quantities of urea, but roosting bats lack access to the drinking water necessary to dilute. Their kidneys instead shift to producing small quantities of highly concentrated urine to dispose of the urea load while conserving as much water as possible.

What did Correns do?

Figured out that zygotes receive all plastids from the cytoplasm of the egg and none from the sperm by observing the coloration patterns in plants. These plastids are leucoplasts, chromoplasts, chloroplasts. Also, offspring receive mitochondrial genes from egg, too.

Type I survivorship curve

Flat at the start, reflecting low death rates during early and middle life, and then drops steeply as death rates increase as you get older (humans)

Incomplete flowers

Flowers that lack one or more of the floral organs.

Complete flowers

Flowers with stamens, carpels, petals, and sepals.

Hydrostatic skeletons

Fluid held under pressurein a closed body compartment (earthworm. Use muscles to change the shape of fluid filled compartments. Cavity must elongate when it diameter is decreased because water maintains its volume under pressure.

Declining pop. approach

Focuses on threatened and endangered populations that show a downward trend, even if the population is far above its minimum viable population.

FSH

Follicle-Stimulating Hormone; Gonadotropin; A tropic hormone that is produced and secreted by the anterior pituitary and that stimulates the production of eggs by the ovaries and sperm by the testes. Stimulates Sertoli cells, located within the seminiferous tubules, to nourish developing sperm.

Achondroplasia

Form of dwarfism that occurs in 1/25k people. Caused by dominant allele.

Who was Jeffrey Bada and what did he do?

Former grad student of Stanley Miller (2007), who discovered vials of unanalyzed samples from an experiment by Miller in 1958. He simulated volcanic activity by using hydrogen sulfide gas (H₂S), and saw how it reacted with the samples in the vials. After three days of simulation, he analyzed the samples and found amino acids.

Cardiac muscle

Forms contractile wall of the heart. Striated. Has fibers that interconnect via intercalated disks, which relay signals cell to cell and help synchronize heart contraction.

Evidence for Evolution - The Fossil Record

Fossil record documents the pattern of evolution, showing that past organisms differed from present day organisms and have gone extinct while also showing the evolutionary changes that have occurred in various groups of organisms. Recent discoveries in the fossil record document steps in the transition from life on land to life in the sea, bridging the gaps between the ancestry of cetaceans and terrestrial mammals.

Nitrogen importance

Found in AA, proteins, and nucleic acids, and is often a limiting plant nutrient.

Astrocytes

Found in the CNS, facilitate information transfer at synapses and in some instances release neurotransmitters. Astrocytes next to active neurons cause nearby blood vessels to dilate, increasing blood flow and enabling the neurons to obtain oxygen and glucose more quickly. Astrocytes also regulate extracellular concentrations of ions and neurotransmitters. Participate in formation of the BB, that restricts the entry of most substances form the blood in the CNS.

Endemic

Found nowhere else in the world.

Cardiac Muscle

Found only in the heart. Striated. Ion channels in the plasma membrane of cardiac cells cause rhythmic depolarizations that trigger action potentials without nervous system input. Electrically coupled by specialized regions called intercalated disks. This coupling enables the action potential generated by specialized cells in one part of the heart to spread, casuing the whole heart to contract.

In what direction are polynucleotides built?

From 5' to 3'.

Sclerenchyma cells

Function as supporting elements in the plant, but much more rigid than collenchyma. Secondary cell wall (produced after cell elongation) is thick and contains large amounts of lignin. Mature sclerenchyma cells cannot elongate, and they occur in regions of the plant that have stopped growing in length. Sclerenchyma cells are so specialized for support that many are dead at functional maturity, but they produce secondary walls before the protoplast dies. The rigid walls remain as a skeleton that supports the plant.

Repressible enzymes

Function in anabolic pathways, which synthesize essential end products from raw materials (precursors). By suspending production of an end product when it is already present in sufficient quantity, the cell can allocate its organic precursor and energy for other uses.

Gastrovascular Cavity

Functions in the distribution of substances throughout the body, as well as digestion, in cnidarians. Opening on one end connects the cavity to the surrounding water. Fluid bathes both the inner and outer tissue layers, facilitating exchange of gas and cell waste. Because the body wall is a mere two cells thick, nutrients need diffuse only a short distance to reach the cells of the outer tissue layer.

Endophytes

Fungi living inside all plants species yet surveyed that protect the plants from pathogens, herbivores by making toxins, drought, and metal resistance.

Coenocytic Fungi

Fungi that lack septa. These organisms consist of a continuous cytoplasmic mass having hundreds or thousands of nuclei. Can move large amounts of cytoplasm rapidly (ex. to inflate a button mushroom)

Molds

Fungi that reproduce asexually by growint as filamentous fungi that produce haploid spores by mitosis. These fungi must form visible mycelia to qualify as molds.

Why do organisms thrive in edge areas?

Gain resources from both adjacent areas.

Example of character displacement

Galapagos finches. Allopatric populations of Geospiza fuliginosa and Geospiza fortis on Los Hermanos and Daphne Islands have similar beak morphologies and presumable eat similarly sized seeds. However, where the two species are sympatric on Santa Maria and San Cristobal, G. fuliginosa has a shallower, smaller beak and G. fortis a deeper, larger one: adaptations that favor eating different sized seeds.

Vitreous humor

Gelatinous fluid in the posterior chamber of the eye that maintains the shape of the eyeball and presses the retina against the choroid.

Orthologous genes

Gene duplication homology that is the result of a speciation even and hence occurs between genes found in different species.

How does chromosomal changes expand the genome?

Gene duplications that do not have severe effects can persist over generations, allowing mutations to accumulate. The result is an expanded genome with new genes that may take on new functions. Ex. of increase in genes: Ancestors of mammals used to have only 1 gene for detecting odors. Now, humans have about 350 genes and mice have 1k. This dramatic proliferation probably helped early mammals by allowing them to detect faint odors and distinguish among many different smells.

How does the master regulatory gene, myoD, affect cell differentiation?

Gene encodes MyoD protein, a transcription factor that binds to specific control elements in the enhancers of various target genes and stimulates their expression. Target-genes for MyoD encode other muscle-specific transcription factors. MyoD also stimulates expression of the myoD gene itself, an example of positive feedback that perpetuates MyoD"s effect in maintaining the cell's differentiated state. Finally, the secondary transcription factors activate the genes for proteins such as myosin and actin that confer the unique properties of skeletal muscle cells.

bicoid

Gene in drosophila. An embryo or larva whose mother has two mutant bicoid alleles lacks the front half of its body, and has posterior structures at both ends. This phenotype suggests that the product of the mother's bicoid gene is essential for setting up the anterior end of the fly and might be concentrated at the future anterior end of the embryo.

Y linked gene

Gene located on the Y chromosome

Pgi

Gene which codes for the enzyme phosphogluciosomerase. Catalyzes the second step of glycolysis, and it's activity correlates with the rate of CO2 production from respiration by the butterflies. Heterozygous individuals flew more than twice as fain the morning nd flower ambient temperatures than homozygous individuals. The results indicated a fitness advantage to the heterozygous genotype in low temperatures and a greater likelihood of heterozygotes colonizing new locations in the meta population.

Chemoreceptors

General receptors + Specific Receptors Ex: Osmoreceptors in the mammalian brain detect changes in total solute concentration of blood and stimulate thirst. Antennae of male silkworm moth- detect the two chemical components of the female moth sex pheromone.

Describe the general molecular formula for a monosaccharide

Generally a multiple of the unit CH₂O

Organ identity genes

Genes belonging to the MADS-box family that encode transcription factors that regulates the development of floral patterns. Sepals form the first whorl. Petals second. Stamens third. And carpels fourth.

Homeotic Genes

Genes that control the spatial organization of your body parts. Hox genes provide positional information in an animal embryo. This info. prompts cells to develop into structures appropriate for a particular location. (changes in how in crustaceans changes wimmin appendage to feeding appendage.)

Effects of Genetic Drift

Genetic Drift is significant in small populations: Chance events can cause an allele to be disproportionately over- or underrepresented in the next generation. Although chance events occur in populations of all sized, they tend to alter allele frequencies substantially only in small populations Genetic drift can cause allele frequencies to change at random: Unlike natural selection, which in a given environment consistently favors some alleles over others, genetic drift causes allele frequencies to change at random over time. Genetic drift can lead to a loss of genetic variation within populations by randomly eliminating alleles from a population. Because evolution depends on genetic variation, such losses can influence how effectively a population can adapt to a change in the environment. Genetic drift can cause harmful alleles to become fixed. Alleles that are neither harmful nor beneficial can be lost or become fixed by chance. In very small populations, genetic drift can also cause alleles that are slightly harmful to become fixed. When this occurs, the populations survival can be threatened.

Bottleneck effect

Genetic drift that occurs when the size of a population is reduced, as by a natural disaster or human actions. Typically, the surviving population is no longer genetically representative of the original population.

What is gene variability and how is it quantified?

Genetic variation at the whole gene level that can be quantified as the average percentage of loci that are heterozygous.

Nucleotide variability

Genetic variation measured at the molecular level of DNA. Little of this variation results in phenotypic variation. The reason for this is that many of the differences occur within introns, instead of exons, and of the variations that occur within eons, most do not cause a change in the amino acid sequence of the protein encoded by the gene.

Next Generation Sequencing

Genomic DNA is fragmented and fragments of 400 to 1k base pairs are selected. Each fragment is isolated with a bead in a droplet of aq solution The fragment is copied over and over via PCR. All 5' ends of one strand are specifically "captured" by the bead. Eventually, 10^6 identical copies of the same single strand, which will be used as a template strand, are attached to the bead. The bead is placed into a small well along with DNA polymerases and primers that can hybridize to the 3' end of the template strand. The well is one of 2 million on a multi well plate, each containing a different DNA fragment to be sequenced. A solution of one of the four nucleotides is added to all wells, and then washed off. This is done sequentially for all four nucleotides: dATP, dTTP, dGTP, and then dCTP. The entire process is then repeated. In each well, if the next base on the template strand is complementary to the added nucleotide, the nucleotide is joined to the growing strand, releasing PPi, which causes a flash of light that is recorded. The nucleotide is washed off, and a different nucleotide is added. If not complementary to the next template base, it is not joined to the strand and there is no flash. The process of adding and washing off the four nucleotides is repeated until every fragment has a complete complementary strand. The patter of flashes recalls the sequence of the original fragment in each well.

Oligodendrocytes

Glia; Produce the myelin sheaths surrounding axons in the CNS.

Schwann cells

Glia; Produce the myelin sheaths surrounding axons in the PNS

How is chitin different from cellulose?

Glucose monomer has a nitrogen-containing appendage in chitin.

Which Side chains have no asymmetric carbon? What is the effect of this?

Glycine and proline. Any molecule with proline will "kink" since the H₂N⁺ creates a point of non-rotaion in the protein structure.

Statoliths

Granules formed by grains of sand or other dense materials, which sit freely in a chamber with ciliated cells.

Srb and Horowitz Experiment.

Grew three classes of arginine-requiring Neurospora mutants, plus a minimal medium as a control, knowing Neurospora could grow on MM but mutant cells couldn't. While the wild type strain was capable of growth under all experimental conditions, the three classes of mutants each had a specific set of growth requirements. The mutant unable to carry out one step in the pathway for synthesizing argenine presumable lacked the necessary enzyme, and since each of their mutant was mutated in a single gene, concluded each mutated gene must normally dictate the production of one enzyme.

Net Primary Production

Gross Primary Production - the energy used by the primary producers for their "autotrophic respiration" (Ra). ON AVERAGE, NPP IS ABOUT 1/2 GPP.

Cortex

Ground tissue that is external to the vascular tissue. Region between the vascular cylinder and epidermis. Cortical cells store carbs _ transport water and salts from the root hairs to the center of the root. The cortex, because of its large intercellular spaces, also allows for the extracellular diffusion of water, minerals, and oxygen from the root hairs inward.

Sister taxa

Groups of organisms that share an immediate common ancestor and hence are each other's closest relatives

Gene families

Groups of related genes within an organisms genome

Clades

Groups that include an ancestral species and all of its descendants.

Apical bud

Growing shoot tip, where most of the growth of a young shoot is concentrated.

Where does assimilated biomass assimilated to?

Growth (new biomass; secondary production) and cellular respiration

Secondary growth

Growth in circumference in parts of stems and roots of woody plants that no longer grow in length. Growth in thickness. Consists of the tissues produced by the vascular cambium and cork cambium. Vascular cambium adds secondary xylem (wood) and secondary phloem, thereby increasing vascular flow and support for the shoots. Cork cambium produces a tough, thick covering of waxy cells that protect the stem from water loss and from invasion by insects, bacteria, and fungi. Because each new layer of secondary xylem has a larger circumference, secondary growth allows the xylem to transport more sap each year. During each growing season, secondary growth increases the diameter of the parts that formed in previous years.

Behavior to ++ certainty of paternity

Guarding females, removing sperm from the female repoductive tract before copulation, introducing large quantitites of sperm that displace the sperm of other ales.

Gymnosperms vs. Angiosperms

Gymnosperms: Seeds borne on unenclosed sporophylls Xylem with tracheids only Often needle-like leaves with thick cuticle and stomata in pits (megaphylls adapted for dry conditions. Angiosperms: Seeds inside ovary walls Xylem with tracheids, fibers, and vessel elements Flowers- clusters of sporophylls surrounded by specialized leaves Fruit for protection and dispersal of seeds

Wetlands

Habitat that is inundated by water at least some of the time.Marshes and swamps often drained for building sites or mosquito control or filled in with dredge soil; wetlands have huge primary productivity and act as important nurseries for fish populations.

Generative cell

Haploid cell in male gametophytes that forms two sperm during the angiosperm life cycle

Tube Cell

Haploid cell that produces a pollen tube during the angiosperm life cycle.

Blood

Has a liquid extracellular matrix called plasma, which consists of water, salts, and dissolved proteins. Suspended in plasma are RBC's and WBC's and cell fragments called platelets.

Cis-trans (geometric) isomers

Have covalent bonds to the same atoms, but these atoms differ in their spatial arrangements due to the inflexibility of double bonds. While single bonds allow the atoms to rotate freely about the bond axis without changing the compound, double bonds between atoms inhibit such rotations. The subtle difference between cis and trans isomers can dramatically affect the biological activities or organic molecules.

Parenchyma

Have primary walls that are relatively thin and flexible, and most lack secondary walls. When mature, parenchyma cells generally have a large central vacuole. Parenchyma cells perform most of the metabolic functions of the plant, synthesizing and storing various organic products. Some parenchyma cells in stems and roots have colorless plastids that store starch. The fleshy tissue of many fruits is composed mainly of parenchyma cells. Most parenchyma cells retain the ability to divide and differentiate into other types of plant cells under particular conditions- during wound repair (ex). It is even possible to grow an entire plant from a single parenchyma cell.

Polyploidy

Having two complete chromosome sets in all somatic cells. Strawberries are octopoid.

Homozygous

Having two identical alleles for a given gene. Breed true.

Anterior-posterior

Head-to-tail

Females with Trisomy X

Healthy and usually taller than average. At higher risk for learning disabilities

Double circulation in birds/mammals

Heart has two atria and two completely divided ventricles. Left side receives and pumps only oxygen rich blood, while the right side receives and pumps only oxygen poor blood.

What two factors determine cardiac output?

Heart rate and stroke volume.

Ex. Of Mark/Recapture method?

Hector's Dolphins by photographing their distinctive dorsal fins from boats.

Collenchyma cells

Help support young parts of the plant shoot. Collenchyma cells are generally elongated cells that have thicker primary walls than parenchyma cells, though the walls are unevenly thickened. Young stems and petioles often have strands of collenchyma cells just below their epidermis. Collenchyma cells provide flexible support without restraining growth. At maturity, these cells are living and flexible, elongating with the stems and leaves they support

Activation of B Cells

Helper T recognizes class II MHC complex with antigen fragment in antigen presenting cell and is activated when AP cell secretes cytokines. When a B cell ith receptors for the same epitope internalizes the antigen it displays an antigen fragment on the cell surface in a complex with a class II MHC molecule. An activated hlper T cell bearing receptors specific for the displayed fragment binds to and activates the B cell. The activated b cell proliferates and differentiates into Memory B cells and antibody-secreting plasma cells. The secreted antibodies are specific for the same antigen that initiiated the response.

Why process filtrate in the proximal tubule?

Helps maintain a relatively constant pH in body fluids: Cels of the transport epithelium secrete H+ ions into the lumen of the tubule but also synthesize and secrete ammonia, which acts as a buffer to trap H+ in the form of ammonium ions. The more acidic the filtrate is, the more ammonia the cells produce and secrete, and a mammals urine usually contains some ammonia from this source. The proximal tubules also reabsorb about 90% of the buffer bicarbonate from the filtrate, contributing further to pH balance in body fluids.

Open circulatory system

Hemolymph is also the interstitial fluid that bathes body cells. Heart contractions pumps the hemolymph throughout the circulatory vessels into interconnected sinuses. Within the sinuses, chemical exchange occurs between hemolymph and body cells. Relaxation of heart draws hemolymph back through pores equipped with valves that close when the heart contracts. Body movements periodically squeeze the sinuses, circulating the hemolymph. Less costly than closed systems.

Why is secondary production only a fraction of net primary production?

Herbivores eat only a small fraction of plant material produced (only 1/6 globally) They cannot digest all the plant material they DO eat, as anyone who has walked through a dairy farm will attest.

Carrier

Heterozygotes that may transmit the recessive allele to their offspring, but are phenotypically normal.

Dendrites

Highly branched extensions in neurons that, with the cell body, receive signals from other neurons.

What traits do charophytes share with land plants?

Homologous cell walls with rings of cellulose-synthesizing proteins, structure of flagellated sperm, formation of a phragmoplast, homologous peroxisome enzymes, homologous nuclear and chloroplast genes.

Gonadotropins

Hormones that act on the male and female gonads that support gametogenesis by stimulating sex hormone production.

Karyogamy

Hours, days, or centuries after plasmogamy, the haploid nuclei contributed by two parents fuse, producing diploid cells. Zygotes and other transient structures form. Meiosis then restores the haploid condition, ultimately leading to the formation of genetically diverse spores. Meiosis is a key step in sexual reproduction, so spores produced in this way are sometimes referred to as "sexual spores."

1/10 billion

How many times does DNA replication error in humans?

DNA Pol III

Huge Multienzyme complex with 10 different kinds of polypeptides. High processivitiy (adds 1000s of nukes before leaving template), high speed (1000 nukes/sec) and high accuracy because it checks the pairing of the previous nucleotide before adding the next and thus MUST have an existing C3 platform to add new nucleotides. Using parental DNA as a template, synthesizes new DNA strand by adding nucleotides to an RNA primer or a pre-existing DNA strand

Stability

Hybrid Zone where hybrids continue to be produced. Occurs because hybrids survive or reproduce better than members of either parent species, at least in certain habitats or years. But stable hybrid zones have also been observed in cases where the hybrids are selected against.

How do phospholipids react with water?

Hydrocarbon tails are hydrophobic and excluded from water. Phosphate group and its attachments form a hydrophilic head with an affinity for water. This forces them to self-assemble into double-layered structures, or bilayers, that shield their hydrophobic portions from water, like seen in a cell.

Explain the biological significance of Glycogen?

Hydrolysis of glycogen in liver and muscle cells releases glucose when the demand for sugar increases. Glycogen stores are depleted in about a day for humans.

List the non-polar side chains.

Hydrophobic; Glycine, Alanine, Valine, Leucine, Isoleucine, Methionine, Phenylalanine, Tryptophan, Proline.

List the seven chemical groups mot important to biological processes

Hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, and methyl.

Lineage-based mechanism

Hypothesis for how plant cells differentiate that propose that cell fate is determined early in development and that cells pass on this destiny to their progeny.

Position-based mechanism

Hypothesis for how plant cells differentiate that propose that the cell's final position in an emerging organ determines what kind of cell it will become.

Nervous System

IN animals, the fast-acting internal system of communication involving sensory receptors, networks of nerve cells, and connections to muscles and glands that respond to nerve signals; functions in concert with the endocrine system to effect internal regulation and maintain homeostasis. Well suited for directing immediate and rapid responses to the environment (reflexes, and other rapid movements). Conveys information by the particular pathway the signal takes.

Competitive exclusion principle

IN the absence of disturbance, one species will use the resources more efficiently and reproduce more rapidly than the other. Even a slight reproductive advantage will eventually lead to local elimination of the inferior competitor. Both organisms must be vying for the same resource.

Maximum likelihood

Identifies the tree most likely to have produced a given set of DNA data based on certain probability rules about how DNA sequences change over time.

Under what circumstances would each side of these competitions be most likely to achieve exponential growth in population?

If all interspecific aspects of the relationship are eliminated, and resources are abundant.

What is a fixed allele in the gene pool?

If only one allele exists for a particular locus in a population. All individuals are thus homozygous for that allele

What does E.Coli do with tryptophan?

If the environment is lacking the amino acid tryptophan, which the cell needs, the cell activates a metabolic pathway that makes tryptophan from another compound (regulates enzyme activity). Later, if the cell's environment has available tryptophan, the bacterial cell stops producing tryptophan (regulate gene expression).

Mendel's third concept of heredity

If the two alleles at a locus differ, then one, the dominant allele, determines the organism's appearance; the other, the recessive allele, has no noticeable effect on the organism's appearance.

Four major characteristics of adaptive immunity

Immense diversity of lymphocytes and receptors, enabling the immune system to detect pathogens never before encountered. Adaptive immunity normally has self tolerance. Cell proliferation triggered by activation greatly increases the number of B and T cells specific for an antigen. There is a stronger more rapdi response to an antigen encountered previously, due t immunological memory.

Autoimmune disease

Immune system is active against particular molecules of the body. Lupus, Arthritis. Caused by heredity, gender, and environment. And stress.

Nucleic Acid Probe

In DNA technology, a labeled single-stranded nucleic acid molecule used to locate a specific nucleotide sequence in a nucleic acid sample. Molecules of the probe hydrogen-bond to the complementary sequence wherever it occurs; radioactive, fluorescent or other labeling of the probe allow its location to be detected.

What else does CAP do?

In addition to regulating the lac operon, CAP helps regulate other operons that encode enzymes used in catabolic pathways. It may affect the expression of more than 100 genes in E. coli. When glucose is plentiful and CAP is inactive, the synthesis of enzymes that catabolize compounds other than glucose generally slows down.

Nervous Tissue

In animals, the fast-acting internal system of communication involving sensory receptors, networks of nerve cells, and connections to muscles and glands that respond to nerve signals; functions in concert with the endocrine system to effect internal regulation and maintain homeostasis.

Endocrine System

In animals, the internal system of communication involving hormones, the ductless glands that secrete hormones, and the molecular receptors on or in target cells that respond to hormones; functions in concert with he nervous system to effect internal regulation and maintain homeostasis. Coordinates gradual changes that affect the entire body (growth, development, reproduction, metabolic processes, and digestion.

Operator

In bacterial and phage DNA, a sequence of nucleotides near the start of an operon to which an active repressor can attach. The binding of the prepress prevents RNA polymerase from attaching to the promoter and transcribing the genes of the operon. The "switch" used by bacteria that groups genes of related function. Controls the attachment of RNA polymerase.

Filtration

In excretory systems, the extraction of water and small solutes, including metabolic wastes, from the body fluid.

Sensor

In homeostasis, a receptor that detects a stimulus

Juxtamedullary Nephron,

In mammals and birds, a nephron with a loop of Henle that extends far into the renal medulla. Essential for production of urine that is hyper osmotic to body fluids.

Hormones

In multicellular organisms, one of the many types of secreted chemicals that are formed in specialized cells, travel in body fluids, and act on specific target cells in other parts of the organism, changing the target cells' functioning.

Meristematic activity in monocots/grasses

In some monocots/grasses, meristematic activity occurs at the bases of stems and leaves.

Structure of flagellated sperm

In species of land plants that have flagellated sperm, the structure of the sperm closely resembles that of charophyte sperm.

Purpose of Apical Meristems

In terrestrial habitats, a photosynthetic organism finds essential resources in two very different places. Light and CO2 are mainly available above ground; water and mineral nutrients are found mainly in the soil. Though plants cannot move from place to place, their roots and shoots can elongate, increasing exposure to environmental resources. This growth in length is sustained throughout the plants life by the activity of apical meristems.

Angiosperm life cycle

In the megasporangium of each ovule, the megasporophyte divides by meiosis, producing four megaspores. One survives and gives rise to a female gametophyte. On the anther, each microsporangium contains microsporocytes that divide by meiosis, producing microspores. (2N) MEIOSIS A microspore develops into a pollen grain. The generative cell of the gametophyte will divide, forming two sperm. The tube cell will produce the pollen tube. After pollination, eventually two sperm cells are discharged in each ovule (n) FERTILIZATION Double fertilization occurs. One sperm fertilizes the egg, forming a zygote. The other sperm fertilizes the central cell, forming the endosperm (3n) The zygote develops into an embryo that is packaged along with food into a seed. When a seed germinates, the embryo develops into a mature sporophyte.

Proximal tubule

In the vertebrate kidney, the portion of a nephron immediately downstream from Bowman's capsule that conveys and helps refine filtrate. NaCl in the filtrate enters the cells of the transport epithelium by facilitated diffusion and cotransport mechanisms. The epithelial cells actively transport Na+ into the interstitial fluid, and this transfer of positive charge out of the tubule drives the passive transport of Cl-. As salt moves from the filtrate to the interstitial fluid, water follows by osmosis. The salt and water then diffuse from the interstitial fluid into the peritubular capillaries. Glucose, amino acids, K+ ions, and other essential substances are also actively or passively transport from filtrate to interstitial fluid and then to peritubular capillaries. As filtrate passes through he proximal tubules, materials to be excreted become concentrated.

Distal tubule

In the vertebrate kidney, the portion of a nephron that helps refine filtrate and empties it into a collecting duct. Contributes to pH regulation by the controlled secretion of H+ and reabsorption of HCO3-. Plays a key role in regulating the K+ and NaCl concentration of body fluids. Regulation involves variation in the amount of K+ secreted into the filtrate as well as the amount of NaCl reabsorbed from the filtrate.

Kidneys

In vertebrates, a pair of excretory organs where blood filtrate is formed and processed into urine.

Zone of cell division

Includes the root apical meristem and its derivatives. New root cells are produced in this region, including cells of the root cap.

Organismal ecology

Includes the sub disciplines of physiological, evolutionary, and behavioral ecology, is concerned with how an organism's structure, physiology, and behavior meet the challenges posed by its environment.

Double circulation in turtles/snakes/lizards

Incomplete septum partially divides the single ventricle into separate right and left chambers.

Effect of ozone depletion

Increase intensity of UV rays reaching Earth's surface. Scientists expect increases in both lethal and nonlethal forms fo skin cancer and cataracts, as well as unpredictable effects on crops and natural communities, especially the phytoplankton that are responsible for a large proportion of Earth's primary production. Amount of UV radiation reaching the ground sharply increased in ozone hole area, causing more DNA damage in plants that were not protected by filters.

Genetic Diversity

Individual genetic variation within a population + genetic variation between populations that is often associated with adaptations to local conditions.

Autopolyploid

Individual that has more than two chromosome sets that are all derived from a single species (failure of cell division)

Clumped Dispersion

Individuals are clustered together due to social benefits or beneficial microclimates (chimps in a troop or sow bugs under a log or sea stars)

What were Darwin's 2 inferences?

Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than other individuals This unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population of generations.

Anaphylactic Shock

Inflammatory chemicals released from mast cells trigger constriction of bronchioles and sudden dilation of peripheral blood vessels, causing a large drop in blood pressure. Epinephrine counters, constricting blood vessels and relaxing muscles in the lungs.

Positive pressure breathing

Inflating the lungs with forced airflow. Frog. First stage of inhalation, muscles lower the floor of an amphibian's oral cavity, drawing in air through its nostrils. Next, when the nostrils and mouth close, the floor of the oral cavity rises, forcing air down the trachea. During exhalation, air is forced back out by the elastic recoil of the lungs and by compression of the muscular body wall.

Explain gradated phenotypic differences

Influence of two or more genes on a single phenotypic character. Many of these characters are influenced by multiple genes (ie. coat color, seed number in corn, height in humans)

Epigenetic Inheritance

Inheritance of traits transmitted by mechanisms not involving the nucleotide sequence itself. Whereas mutations in the DNA are permanent changes, these modification to the chromatin can be reversed.

Adaptations

Inherited characteristics of organisms that enhance their survival and reproduction in specific environments.

Uric Acid

Insects, land snails, many reptiles. Nitrgenous waste. Relatively nontoxic and does not readily dissolve in water. Can be excreted as a semisolid paste with very little water loss. Most energy expensive to make, requiring considerable ATP for synthesis. Humans generate a small amount from purine breakdown.

Describe gene therapy using a retroviral vector

Insert RNA version of normal allele into retrovirus or other viral vector Let virus infect bone marrow cells that have been removed from the patient and cultured Viral DNA carrying the normal allele inserts into chromosome Inject engineered cells into patient

How does recognition of protein antigens by T cells occur?

Inside host cell, enzymes cleave the antigen into smaller peptides. Each peptide, called an antigen fragment, then binds to an MHC molecule inside the cell. Movement of MHC molecule and bound antigen fragment up to the cell surface results in antigen presentation. If the cell displaying an antigen fragment encounters a T cell with the right specificity, the antigen receptor on the T cell can bind to both the antigen fragment and the MHC molecule.

Global Air Circulation and Precipitation Patterns

Intense solar radiation near the equator initiates a global pattern of air circulation and precipitation. High temperatures in the tropics evaporate water from Earth's surface and cause war, wet air masses to rise and flow towards the poles. As the rising air masses cool, they release much of their water content, creating abundant precipitation in tropical regions. The high altitude air masses, now dry, descend toward Earth around 30° North and South, absorbing moisture from the land and creating an arid climate conducive to the development of deserts. Some of the descending air then flows toward the poles. At latitudes around 60° north and south, the air masses again rise and release abundant precipitation. Some of the cold, dry rising air then flows back tot he poles, where it descends and flows back toward the equator, absorbing moisture and creating the comparatively rainless and bitterly cold climates of the polar regions.

Nervous system in cnidarians

Interconnected neurons form a diffuse nerve net which controls the contraction and expansion of the gastrovascular cavity.

Type II Survivorship Curve

Intermediate curves with a constant death rate over an organism's life span (ground squirrels)

Circadian clock

Internal mechanism that maintains a 24 hour activity rhythm or cycle. Helps animals track their position relative to the sun during migration.

Mycelium

Interwoven mass formed by fungal hyphae that infiltrates the material on which the fungus feeds. Structure maximizes SA/Vol. ratio, making feeding very efficient. Grows rapidly.

Effects of gene flow

Introduce allele and modify allele frequency, reducing genetic differences between populations. If extensive enough, gene flow can result in two populations combining into a single population with a common gene pool. Can affect how well populations are adapted to the local environment depending on the introduction of an advantageous/disadvantageous allele. Gene flow can potentially be so high that it overwhelms the effects of selection. Gene flow helps reduce genetic differences via exchange of alleles between human populations that previously had little contact.

What is the relationship between the energy it takes to maintain each gram of body mass vs body size?

Inversely related. Mice need about 20 times as many calories per gram as elephants, even though the whole elephant uses more calories.

Gated ion channels

Ion channels that open or close in response to stimuli. The opening or closing of gated ion channels alters the membrane's permeability to particular ions, which in turn alters the membranes potential.

How does evolution help explain biogeographic data?

Islands have many endemic species that are closely related to species on the nearest mainland/island. This suggests that islands are colonized by species from the nearest mainland, which eventually give rise to new species as they adapt, explaining why two islands with similar environments in distant parts of the world tend to be populated by species unrelated to each other, but related to each's mainland, where the environment is often different.

Enantiomers

Isomers that are mirror images of each other and differ in shape due to the presence of an asymmetric carbon. These mirror-image isomers won't fit in the same places, affecting their biological functions.

Consequence of Mass Extinction

It typically takes 5-10 million years for the diversity of life to recover to previous levels- in some longer. Alters ecological communities by changing the types of organisms residing there. Curtail lineages with novel and advantageous features.

Which reproductive strategy is most vulnerable to extinction? Why?

Iteroparity: Less offspring and less genetic variation in the event of a genetic drift event (ie. Bottleneck). Less variability = lower likelihood of survival.

What is the function of a protein dependent on?

Its ability to recognize and bind to some other molecule. Morphine and heroin are able to mimic endorphins' effect on the brain because they all share a similar shape, and can fit into and bind to endorphins receptors in the brain.

What creates the negative charge inside neurons?

K+ leak channels are always open, and the concentration favors a net outflow of K+. But because Na+ and other ions can't readily cross the membrane, K+ outflow leads to a net negative change inside the cell. The net flow of K+ out of a neuron proceeds until the chemical and electrical forces are in balance.

Disadvantages of life on land

Lack of support, lack of water to transport gametes for sexual reproduction, separation of light availability from water availability.

Mesophyll

Leaf's ground tissue. Sandwiched between the upper and lower epidermal layers. Consists mainly of parenchyma cells specialized for photosynthesis. Has two distinct layers, palisade and spongy

Leaves

Leaves increase the surface area of the plant body and serve as the primary photosynthetic organ of vascular plants.

Megaphylls

Leaves with a highly branched vascular system. Megaphylls are typically larger than microphylls and therefore support greater photosynthetic productivity than microphylls.

Slow twitch

Less SR, pumps Ca+2 more slowly. Because Ca+2 remains in the cytosol longer, a muscle twitch in a slow twitch fiber lasts about 5x as long as one in a fast fiber. Just oxidative.

Alternation of generations

Life cycle of all land plants that alternates between two generations of distinct multicellular organisms: gametophytes and sporophytes. Each generation gives rise to the other. Life cycle includes both multicellular haploid organisms and multicellular diploid organisms. Gametophyte produces haploid egg/sperm >> Egg/sperm fuse during fertilization, forming diploid zygote >> mitosis of zygote produces multicellular sporophyte >> meiosis of sporophyte produces haploid spores >> mitosis of the spore cell produces a new multicellular gametophyte

Advantages of life on land

Light unfiltered by water, initially less competition for light, lots of CO2 in the air, mineral nutrients in soil, lots of space, few herbivores initially/predation

Nutrient Limitation

Limits primary production in most oceans and lakes. Nutrient most often limiting marine production is either nitrogen or phosphorus. Concentrations of these nutrients are typically low in the photic zone because they are rapidly taken up by phytoplankton and because detritus tends to sink.

Role of Fe

Limits primary production in the sargasso sea, which has some of the clearest water in the world because of its low phytoplankton density. Windblown dust from land supplies most of the iron to the oceans but is relatively scarce in this and certain other regions compared to the oceans as a whole.

What macromolecule is not a polymer?

Lipids are not polymers

Liverworts

Liver-shaped gametophytes. In medieval times, their shape was thought to be a sign that the plants could help treat liver diseases. Some described as "thalloid" because of the flattened shape of their gametophytes. Sporophytes have a short seta with an oval or round capsule.

Lungs

Localized respiratory organs. Typically subdivided into numerous pockets.

Semilunar Valves

Located at the two exits of the heart, where the aorta leaves the left ventricle and the pulmonary artery leaves the right ventricle. These valves are pushed open by the pressure generated during contraction of the ventricles. When the ventricles relax, blood pressure built up in the aorta and pulmonary after closes the semilunar valves and prevents significant back flow.

How does the structural organization of chromatin help regulate gene expression?

Locations of a gene's promoter, relative to both the placement of nucleosomes and sites where the DNA attaches to the chromosome scaffold, can affect whether the gene is transcribed. Genes without heterochromatin, which is highly condensed, are usually not expressed. Certain chemical modifications to the histone proteins and to the DNA of chromatin can influence both chromatin structure and gene expression.

Why is phosphorus availability low in deserts and ecosystems with a basic pH?

Locations where some phosphorus precipitates and becomes unavailable to plant.

Fatty acid

Long carbon skeleton, usually 16-18 carbon atoms in length. Carbon at one end of the skeleton is part of a carboxyl group. The rest of the skeleton consists of a hydrocarbon chain. Relatively non-polar C-H bonds in the chain are the reason fats are hydrophobic.

Vessels

Long pipes that are part of vessel elements.

Hornworts

Long, tapered-shaped sporophyte. Typically grows 5cm high. Hornwort sporophyte lacks a seta and consists only of a sporangium. The sporangium releases mature spores by splitting open, starting at the tip of the horn. Gametophytes, 1-2cm, drowned mostly horizontally and often have multiple sporophytes attached. Hornworts are frequently among the first species to colonize open areas with moist soils; a symbiotic relationship with nitrogen fixing cyanobacteria contributes to their ability to do this.

Rhizoids

Long, tubular single cells (in liverworts and hornworts)or filaments of cells (in mosses). Unlike roots, rhizoids are not composed of tissues. Bryophyte rhizoids also lack specialized conducting cells and do not play a primary role in water and mineral absorption.

Deletion

Loss of nucleotide pairs in a gene

How does production of CO2 promote unloading of O2 by hemoglobin?

Low pH decreases the affinity of hemoglobin for O2. Where Co2 production is greater, hemoglobin releases more O2.

LH

Luteinizing Hormone; A tropic hormone that is produced and secreted by the anterior pituitary and that stimulates ovulation in females and androgen production in males. Causes Leydig cells, scattered in connective tissue between the tubules, to produce testosterone and other androgens, which promote spermatogenesis.

Polynucleotides

Macromolecules that exist as polymers of nucleic acids.

Polysaccharides

Macromolecules, polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages.

Androgens

Main sex steroid hormones

Biomes

Major life zones characterized by vegetation type in terrestrial biomes or by the physical environment in aquatic biomes.

What's the biological significance of monosaccharides?

Major nutrients for cells. Used for cellular respiration to give energy to cells after being broken down in a series of reactions. Carbon skeletons serve as raw material for the synthesis of other types of small organic molecules, like amino and fatty acids. Incorporated into disaccharides or polysaccharides.

Carpels

Make megaspores and their products, female gametophytes. Consists of stigma, style, and ovary.

Pollen grain

Male gametophyte enclosed within a pollen all made of an outer layer with molecules secreted by sporophyte cells. Developed from a microspore. Sporopollenin in the polen wall protects the pollen grain as it is transported by wind or by hitchhiking on an animal. Sperm do not require motility because they are carried to the eggs by pollen tubes.

Describe excretion in grasshoppers

Malpighian tubules extend from dead-end tips immersed in hemolymph to openings into the digestive tract. The filtration step common to other excretory systems is absent. Instead, the transport epithelium that lines the tubules secretes certain solutes, including nitrogenous wastes, from the hemolymph into the lumen of the tubule. Water follows the solutes into the tubule by osmosis, and the fluid then passes into the rectum. There, most solutes are pumped back into the hemolymph, and water reabsorption by osmosis follows. The nitrogenous wastes- mainly insoluble uric acid- are eliminated as nearly dry matter along with the feces.

What happens to bengalese subsistence fishermen when the spanish fishing fleet arrives?

Many commercially important fish populations, once thought to be inexhaustible, have been decimated by over fishing. Demands for protein-rich food from an increasing human population, coupled with new harvesting technologies, such as long-line fishing and modern trawlers, have reduced these fish populations to levels that cannot sustain further exploitation.

What's the biological significance of surface tension?

Many small arthropods relay on surface tension for gas exchange or mobility.

Tinman

Master regulatory gene that controls the development of heart structures in flies and vertebrates.

Intersexual selection

Mate choice; Individuals of one sex (usually the females) are choosy in selecting their mates from the other sex. In many cases, the female's choice depends on the showiness of the male's appearance or behavior.

r(max)

Maximum rate of increase for the species

What were Darwin's 2 Observations

Members of a population often vary in their inherited traits All species can produce more offspring than their environment can support, many of these offspring fail to survive and reproduce.

Hemagglutinin

Membrane-bound protein on the envelope of the influenza virus (epitope). Binds to sialic acid on the receptor protein of the host cell. Changes shape after virus is engulfed by host cell into the endosome, which then increases in acidity. The ++ in acidity changes the shape of Hemagglutinin, elongating it so it penetrates the membrane and releases the virus into the cytosol of the host cell, where it can start to reproduce.

Intercalary meristems

Meristems at the bases of stems/leaves. Allow damaged leaves to rapidly regrow, which accounts for the ability of lawns to grow following mowing. The ability of grades to regrow leaves by intercalary meristems enables the plant to recover more effectively from damage incurred from grazing herbivores.

Spongy mesophyll

Mesophyll in edict leaves that is below the palisade mesophyll. These parenchyma are more loosely arranged, with a labyrinth of air spaces through which CO2 and O2 circulate around the cells and up to the palisade region. The air spaces are particularly large in the vicinity of stomata, where CO2 is taken up from the outside air and O2 is released.

Radiometric Dating

Method used to find the age of fossils that is based on the decay of radioactive isotopes. Carbon-14 has a half life of 5730 years. This method works for fossils up to about 75000 years old; older than that contain too little carbon-14 to be detected with current techniques.

How does the microclimate beneath a log in the PEA woods differ from the climate you observe each day as you walk to class?

Micro climate beneath log is protected by shade and more moist and nutrient rich than most of the climate you interact with every day. Also more opportunities for symbiotic relationships between bacteria and legumes, for example.

Gametophytes of seed plants

Microscopic. Thus, their tiny gametophytes can develop from spores retained within the sporangia of the parental sporophyte. This arrangement protects the gametophyte from environmental stress. It also enables the developing gametophytes to obtain nutrients from the parental sporophyte.

Where do sympathetic nerves exit the CNS?

Midway along the spinal cord and form synapses in ganglia located just outside the spinal cord.

Bone

Mineralized connective tissue. Osteoblasts deposit a matrix of collagen. Calcium, magnesium, and phosphate ions combine into a hard mineral within the matrix. Consists of repeating units called osteons, which have concentric layers of the mineralized matrix, deposited around a central canal containing blood vessels and nerves

Monosomic

Missing chromosome; 2n-1; occurs if nondisjunction fails to separate homologous pairs

Bottom Up Model

Model of community organization that postulates a unidirectional influence from lower to higher trophic levels. Ex. Mineral nutrients controls plant numbers which controls herbivore numbers which controls predator numbers.

Top-down model; Trophic cascade model

Model of community organization that postulates that predation mainly controls community organization because predators limit herbivores, herbivores limit plants, and plants limit nutrient levels through nutrient uptake. Ex. In a lake community with four trophic levels, the top-down model predicts that removing the top carnivores will increase the abundance of primary carnivores, in turn decreasing the number of herbivores, increasing phytoplankton abundance, and thus decreasing concentrations of mineral nutrients.

Ferns

Monilophyte Have megaphylls. Sporophytes typically have horizontal stems that give rise to large leaves called fronds, often divided into leaflets. A frond grows as its coiled tip, unfurls. Almost all species homosporous. In most, sporophytes have stalked sporangia with springlike devices that catapulted spores several meters.

Whisk Ferns and relatives

Monilophyte Homosporous, with spores giving rise to bisexual gametophytes that grow underground and are only about a centimeter long. Sporophytes have dichotomoously branching stems but no roots. Stems have scalelike outgrowths that lack vascular tissue and may have resulted from the evolutionary reduction of leaves. Each yellow know on a stem consists of three fused sporangia.

Monocot characteristics vs. Eudicot characteristics

Monocot: 1 cotyledon in embryo. Veins usually parallel in leaves. Vascular tissue scattered throughout stem. Root system fibrous (no main root) Pollen grain with one opening Floral organs usually in multiples of three Woody 2° growth is absent Dicot: 2 cotyledons in embryo. Veins usually netlike in leaves. Vascular tissue arranged in ring throughout stem. Taproot (main root) usually present Pollen grain with three openings Floral organs usually in multiples of 4/5 Woody 2° growth is often present Note: old monocot/dicot clades now being replaced with more groups and monocot/eudicot clades based on DNA homologies

Nucleotides

Monomer for polynucleotide. Composed a five-carbon sugar (pentose), nitrogenous base, one or more phosphate groups. Each monomer has only one phosphate group attached to the 5' carbon of the sugar. Each nitrogenous base has one or two rings that include nitrogen atoms. It's called a nitrogenous base because the nitrogen atoms tend to take up H+ from the solution, acting as a base.

Enhancers

More distant, distal control elements which may be thousands of nucleotides upstream or downstream of a gene or even within an intron. Enhancers are generally associated with only a particular gene, although that particular gene may have multiple other enhancers.

In sensory neurons, a larger receptor potential results in?

More frequent action potentials.

If the receptor is not a sensory neuron, a larger receptor potential usually causes?

More neurotransmitter to be released.

What is an unsustainable amount of consumption

More than 1.7 ha.

Vessel Elements

Most angiosperms, as well as a few gymnosperms/seedless vascular plants, have vessel elements. Generally wider, shorter, thinner walled, and less tapered than tracheids. They are aligned end to end, forming vessels. The end walls of vessel elements have perforation plates that enable water to flow freely through the vessels. The secondary walls of tracheids and vessel elements are hardened with lignin. This hardening provides support and prevents collapse under the tension of water transport

Determinate growth

Most animals and some plant organs undergo (leaves, throne, and flowers). Stop growing after reaching a certain size

Human interactions with seed plants

Most food comes from angiosperms. Crops are products of artificial selection. Flowering plants also provide edible products, such as tea and chocolate. Spices are derived from various plant parts. Seed plants are also sources of wood, the primary source of fuel for much of the world. Humans also depend on seed plants for medicines, such as herbal remedies. Chemical concentrate from willow is used to make aspirin. In the US, about 25% of prescription drugs contain an active ingredient from plants- usually seed plants.

Mosses

Most gametophytes, range in height from less than 1mm to up to 2m, are less than 15 cm tall. Blades of the gametophytes "leaves" are usually only one cell thick, but more complex "leaves" that have ridges coated with cuticle can be found on the common hairy-cap moss. Moss sporophytes are typically elongated and visible to the naked eye, with heights ranging up to about 20 cm. Though green and photosynthetic when young, they turn tan or brownish red when ready to release spores. Many mosses are able to live in very cold or dry habitats because they can survive the loss of most of their body water, then rehydrate when moisture is available.

Describe the configuration of glucose monomers in starch

Most glucose monomers in starch are joined by 1-4 glycosidic linkages.

How does sexual reproduction affect genome variation?

Most of the genetic variation in a population results from the unique combination of alleles that each individual receives from its parents. These differences in alleles at the nucleotide have originated from past mutations, but sexual reproduction then shuffles existing alleles and deals them at random to produce individual genotypes.

Explain Action potentials

Most voltage-gated Na+ channels are closed @ resting potential. Some K+ channels are open. Most aren't Stimulus depolarizes the membrane, some gated Na+ channels open, allowing for more Na+ to diffuse into the cell. The Na+ inflow causes further depolarization, which opens more gated ion channels, and so on. Once threshold is crossed, the positive-feedback cycle rapidly brings the membrane potential close to ENa. Voltage-gated Na channels inactivate soon after opening, halting Na+ inflow. And most voltage gated- K+ channels open, causing rapid out flow of K+. Both events quickly bring membrane potential back to Ek. Membranes permeability to K+ is higher than at rest, so the membrane potential is closer to Ek than it is to the resting potential. Gated K+ channels eventually close, and the membrane potential returns to the resting potential. Sodium potassium pump reestablishes concentration gradient.

Why is only a small fraction of the sunlight that reaches Earth's surface actually used in photosynthesis?

Much of the radiation strikes material that doesn't photosynthesize. Of the radiation that does reach photosynthetic organisms, only certain wavelengths are absorbed by photosynthetic pigments; the rest is transmitted, reflected, or lost a heat. As a result, only 1% of visible light that strikes photosynthetic organisms is converted to chemical energy.

Multicellular, dependent embryos

Multicellular plant embryos develop from zygotes that are retained within the tissues of the female parent (gametophyte). The parental tissues protect the developing embryo from harsh environmental sugars and amino acids. Placental transfer cells enhance transfer of nutrients to the embryo through elaborate ingrowths of the wall surface (plasma membrane + cell wall).

Where do erythrocytes, leukocytes, and platelets all develop from?

Multipotent stem cells.

What are the 4 sources of genetic variation?

Mutations Altering Gene Number or Position Rapid Reproduction Sexual Reproduction

How does rapid reproduction affect genome variation?

Mutations rates are low - 1 mutation per 100000 genes in a generation in plants and animals, and even less in prokaryotes. By proliferating more quickly though, and making more generations per unit time, mutations can quickly generate genetic variation in prokaryote populations. The same is true for viruses. HIV use of RNA genome (lacks repair mechanisms in host cells) + 2 day generation span = large mutation amount/time

Facultative mutualism

Mutualism in which both species can survive alone Ex: Acacia trees and certain ants in Central and south America. Ants feed on nectar produced by tree and protein rich swellings along the bases of leaves. Tree houses stinging ants in its hollow thorns, which attack anything that touches the tree, removing fungal spores, small herbivores, and debris. They also clip vegetation that grows close to the acacia.

Mycorrhizae

Mutually beneficial relationships between haustoria fungi and plant roots. Improve delivery of phosphate ions and other minerals to plants because the vast mycelial networks of the fungi are more efficient than the plants' roots at acquiring these minerals from the soil. In exchange, the plants supply the fungi with organic nutrients such as carbohydrates. Almost all vascular plants have mycorrhizae and rely on their fungal partners for essential nutrients.

Preprophase band

Name for the microtubules in the cytoplasm that become concentrated into a ring

How does air get to the lungs?

Nasal cavity, Pharynx, Larynx, Trachea (Windpipe), Right lunch, Bronchus, Bronchiole, Alveoli

Density-Independent factors

Natural disasters such as volcanic eruptions, hurricanes, and asteroid impacts that tend to kill off all the organisms in an area regardless of their density Ex. Dune fescue dying at a constant rate at different population densities due to "physical factors" independent of population density.

Balancing Selection

Natural selection that maintains two or more phenotypic forms in a population

Fetoscopy

Needle-thin tube containing a viewing scope and fiber optics (to transmit light) is inserted into the uterus. Used to detect major anatomical abnormalities.

Action potentials

Nerve impulses through which sensory information travels in the nervous system.

Vasodilation

Nerve signals relax the muscles of the vessel walls. Results in a widening of superficial blood vessels (near the body surface). Blood flow ++, warms the skin and increases the transfer of body heat to the environment by radiation, conduction, and convection.

What gives the urge to breathe?

Neurons in medulla oblongata use the pH of the surrounding tissue fluid as an indicator of blood CO2 concentration. CO@ diffuses from blood to the cerebrospinal fluid, reacting with water to form carbonic acid. Carbonic acid dissociates to bicarbonate ion and a hydrogen ion, lowering pH. Higher metabolism = more CO2 = more breathing.

Motor neurons

Neurons that extend out of the processing centers triggering output in the form of muscle or gland activity.

Stratified squamous epithelium

New cells formed by division near the basal surface push outward, replacing cells that are sloughed off. This epithelium is commonly found on surfaces subject to abrasion, such as the outer skin, and the linings of the mouth, anus, and vagina.

How are fossils formed?

New layers of sediment cover older ones and compress them into strata.

Can an enzyme that hydrolyzes a starch's α linkages hydrolyze the β linkages?

No - differing shapes of the two molecules. α linkages are easier for enzymes to break up since they align the hydroxides. Beta linkages, every glucose monomer is upside down with respect to its neighbor, allowing for H-Bonds to form when parallel with other cellulose molecules.

What are the conditions for Hardy Weinberg Equilibrium?

No mutations: The gene pool is modified if mutations alter alleles or if entire genes are deleted or duplicated Random mating - If individuals tend to mate within a subset of the population, such as their near neighbors or close relatives, random mixing of gametes does not occur, and genotype frequencies change. No natural selection: Differences in the survival and reproductive success of individuals carrying different genotypes can alter allele frequencies. Extremely large population size: The smaller the population the more likely it is that allele frequencies will fluctuate by chance from one generation to the next (genetic drift) No gene flow: By moving alleles into or out of a population, gene flow can alter allele frequencies.

Detritus

Non-living organic material, such as the remains of dead organisms, feces fallen leaves, and wood. Many are eaten by secondary/tertiary consumers. Ex. Prokaryotes and fungi. Secrete enzymes that digest organic material. Then, absorb the breakdown products. Play a critical role in recycling chemical elements to primary producers. Convert organic matter from all trophic levels to inorganic compounds usable by primary producers.

Fats

Non-polymers; large molecules assembled from smaller molecules by dehydration reactions. Constructed from glycerol and fatty acids.

Bryophytes

Nonvascular plants (not a clade) Liverworts, mosses, hornworts (some mosses do have vascular tissue) - restricted to moist environments both because they lack vascular tissue and because sperm must swim to eggs. Many bryophyte species can increase the number of individuals in a local area through various methods of asexual reproduction.

Where does "autotrophic respiration" come from?

Not all of the GP production can be stored as organic material in the primary producers because they use some of the molecules as fuel in their own cellular respiration.

Lipids

Not true polymers, and generally not big enough to be considered macromolecules. Lipids are grouped with each other based based on not mixing well, if at all, with water. Consist mostly of hydrocarbon regions.

Per capita birth rates

Number of offspring produced per unit time by an average member of the population

Eutrophic Lakes

Nutrient rich and often depleted of oxygen in the deeper zone in summer and covered with ice in the winter. Amount of decomposable organic matter in bottom sediments is high. High rates of decomposition in deeper layers of eutrophic lakes cause periodic oxygen depletion.

Genomic imprinting

Occurs during gamete formation and results in the silencing of a particular allele of certain genes based on the sex of the parent. Mehthyl groups are added to cytosine nucleotides of one of the alleles, usually resulting in a silencing of the allele. However, for a few genes, methylation has been shown to activate expression of the allele. Most known imprinted genes are critical for embryonic development. Example: The mouse gene for insulin-like growth factor 2, Igf2, only expresses the paternal allele. This is because dual expression of both parents' alleles would yield more growth factor, resulting in a bigger embryo that necessitates more resources from the mother. When the allele is mutant and paternal, the mouse is a dwarf, but can still pass on its DNA, making meaning the mother was still biologically successful.

Zero population growth (ZPG)

Occurs when the per capita birth and death rates are equal. Births and deaths still occur in such a population, but they balance each other exactly. r = 0

Allopolyploid

Occurs when two different species interbreed and produce hybrid offspring. Allopolyploids either propagate asexually or are fertile when mating with each other but cannot breed with either parent species.

What was common between all 8 different genes that coded the homeotic proteins?

Of the 1000 or so bases that encoded each of the proteins, all 8 had a short stretch of about 180 base pairs that were very similar in sequence. This suggested that while each homeotic gene had specific effects on particular body regions and parts, the homeotic proteins shared some functional property.

How identical were mice and frog homeoboxes?

Of the 60 AAs of the homeodomain, some mice and frog proteins were identical to the fly sequences at up to 59/60 positions

Eosinophils

Often found beneath mucosal surfaces, are important in defending against multicellular invaders, such as parasitic worms. Upon encountering parasites, eosinophils discharge destructive enzymes.

Heartwood

Older layers of secondary xylem that no longer transport water and minerals. Closer to the center of a stem or root.

Reading Frame

On an mRNA, the triplet grouping of ribonucleotides used by the translation machinery during polypeptide synthesis.- read as a series of non overlapping, 3 letter words.

How do macrophages and neutrophils participate in the inflammatory response?

Once activated, these cells discharge cytokines, which remote blood flow to the site of injury/infection.

Heavy Chain

One of the two types of polypeptide chains that make up an antibody molecule and B cell receptor; consists of a variable region, which contributes to the antigen-binding side, and constant region.

Light Chain

One of the two types of polypeptide chains that make up an antibody molecule and B cell receptor; consists of a variable region, which contributes to the antigen-binding site, and a constant region.

Unsaturated fatty acid

One or more double bonds, with one fewer hydrogen atom on each double-bonded carbon.

Transport epithelia

One or more layers of epithelial cells specialized for moving particular solutes in controlled amounts in specific directions.

Tissue system

One or more tissues organized into a functional unit connecting the organs of a plant

How many different monomers are used to construct a polymer?

Only 40 to 50 common monomers and some others that occur rarely make up life's polymers.

What do the antigen receptors of T cells bind to?

Only to fragments of antigens that are displayed, or presented, on the surface of host cells.

Why are protein-protein interactions crucial to the initiation of eukaryotic transcription?

Only when the complete initiation complex has assembled can the polymerase begin to move along the DNA template strand, producing a complementary strand of RNA.

Statocysts

Organ in invertebrates that relies on mechanoreceptors to sense gravity and maintain equilibrium

Thymus

Organ in the thoracic cavity above the heart where lymphocytes migrate to and then are differentiated into T cells.

Where else does the leaf get used for the caterpillar?

Organic compounds used for cellular respiration and passes the rest in its feces. The energy in the feces remains in the ecosystem temporarily, but most of it is lost from the ecosystem as heat. This is why energy FLOWS THRU, not cycles within, ecosystems.

Describe the thought on organic compounds, pre Wöhler.

Organic compounds were thought to arise only in living organisms, which were believed to contain a life force beyond the jurisdiction of physical and chemical laws.

Amino acid

Organic molecule with both an amino group and a carboxyl group. At the center is an asymmetric carbon called the alpha (α) carbon bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable group symbolized by R

Hydrocarbon

Organic molecules consisting of only carbon and hydrogen.

Adenosine Triphosphate (ATP)

Organic phosphate consisting of an organic molecule called adenosine attached to a string of three phosphate groups. One phosphate splits off as a result of a reaction with water, creating Adenosine diphosphate (ADP) and releasing energy.

Phosphorus Cycle Importance

Organisms require phosphorus as a major constituent of nucleic acids, phospholipids, and ate and other energy storing molecules, and as a mineral constituent of bones and teeth

Invasive species

Organisms that become established outside their native range. The more diverse a community, the more resources captured by that community, leaving fewer resources for the invader and decreasing its survival.

Utricle and Saccule

Organs within the inner ear that allow us to perceive position with respect to gravity or linear movement. Each of these chambers, which are situated in a vestibule behind the oval window, contains hair cells that project into a gelatinous material called the copula. Embedded in this gel are small calcium carbonate particles called otoliths.

Mismatch repair

Other enzymes remove and replace incorrectly paired nucleotides that have resulted from replication errors

Gradual Equilibrium

Other species do not show a punctuated pattern; instead, they appear to have changed more gradually over long periods of time.

Benefits of being a tall plant

Outcompete short plants for access to sunlight. Spores of tall plants could disperse farther than those of short plants, enabling tall species to colonize new environments rapidly. The ability to grow tall gave vascular plants a competitive edge over nonvascular plants.

What is the biological significance of the percentages of the major elements of life from one organism to another?

Overall percentages of C, H, O, N, S, and P are quite uniform from one organism to another, reflecting the common evolutionary origin of all life.

Tertiary structure

Overall shape of a polypeptide resulting from interactions between the side chains (R groups) of the various amino acids. Hydrogen bonds between polar side chains and ionic bonds between positive and negative side chains, disulfide bridges, and van der Waals interactions help stabilize the structure. Their cumulative effect gives the protein a unique shape.

Acid Precipitation

Oxides of S and N from burning fossil fuels are converted to sulfuric and nitric acid when mixing with the water in the air.

Explain the partial charges in water molecules

Oxygen has a partial negative charge since it's more electronegative than hydrogen, which has a partial positive charge. This difference in charges creates a strong attraction called a polar covalent bond, and also allows for hydrogen bonding between molecules.

What is gout caused by?

Painful joint inflammation caused by deposits of uric acid crystals.

How do birds breathe?

Parabronchi over alveoli. When birds breathe, they pass air over the gas exchange surface in only one direction. Incoming fresh air thus does not mix with air that has already carried out gas exchange. Inhalation: Air fills the posterior air sacs. Also passes through the lungs and fills anterior air sacs. Exhalation: Posterior air sacs contract, pushing air into lungs. Anterior air sacs also contract. As they do, air that entered the body at first inhalation is pushed out of the body. Positive Pressure.

Formation of a phragmosplast

Particular details of cell division occur only in land plants and certain charophytes, including the genera Character and Coleochaete. Example: a group of microtubules known as the phragmoplast forms between the daughter nuclei of a dividing cell. A cell plate then develops in the middle of the phragmosplast, across the midline of the dividing cell. The cell plate, in turn, gives rise to a new cross wall that separates the daughter cells.

How is evolution a pattern?

Pattern of evolutionary change is revealed by data from scientific disciplines- these data are facts and observations about the natural world

Adaptive Radiations

Periods of Evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill different ecological roles in their communities that were lost after a mass extinction. Ex: Dinosar/mammal size/diversity Ex2: Radiations initiated when a few organisms make their way to a new, often distant location in which they face relatively little competition form other organisms. Hawaii islands.

Biggest mass extinctions?

Permian (claimed about 96% of marine animal species and drastically altered life in the ocean). Occurred during the most extreme episode of volcanism in the last 500 years. Amt. of CO2 produced warmed global climate 6° C. Rise in CO2 led to ocean acidification, reducing calcium carbonate, necessary to build reefs. Added nutrients to ecosystems, stimulating growth of microorganisms. Cretaceous- 65.5 million years ago. Extinguished more than half of all marine species and eliminated many families of terrestrial plants and animals, including the dinosaurs (minus birds). Asteroid collided with Earth. Debris fallout clay billowed into the atmosphere, blocking sunlight and severely disturbing the global climate for several months.

Latitudinal Gradients

Plant and animal life is generally more abundant and diverse in the tropics than in other parts of the globe.

Walled Spores produced in Sporangia

Plant spores are haploid reproductive cells that can grow into multicellular haploid gametophytes by mitosis. The polymer sporopollenin makes the walls of plant spores tough and resistant to harsh environments. This chemical adaptation enables spores to be dispersed through dry air without harm. The sporophyte has sporangia that produce spores. Within a sporangia, diploid sporocytes undergo meiosis and generate the haploid spores. The outer tissues of the sporangium protect the developing spores until they are released into the air. Multicellular sporangia that produce spores with sporopollenin-enriched walls are key terrestrial adaptations of land plants. Although charophytes also produce spores, these algae lack multicellular sporangia, and their flagellated water-dispersed spores lack sporpollenin.

Desert

Plants adapted for water conservation OR annuals that germinate, bloom, and set seeds only when rains come.

Correlation between size of seed/young animal and survival rate of offspring

Plants and animals whose young are more likely to die often produce many small offspring. Small size may also increase the chance of seedling establishment by enabling the seeds to be carried longer distances to a broader range of habitats.

Why do we have introns?

Play a regulatory role for gene activity by increasing/decreasing transcription rates Allow different cells to make different proteins by using different combinations of eons from a single gene in what is called ALTERNATIVE RNA SPLICING Allow different domains of a protein to recombine via crossovers to produce new proteins more often (EXON SHUFFLING).

Ion channels

Pores formed by clusters of specialized proteins that span the membrane. Allow ions to diffuse back and forth across the membrane.

Endosymbiont theory.

Posits that mitochondria and plastids were formerly small prokaryotes that began living within larger cells. Host cell that was an anaerobe would benefit from endosymbionts that could use the oxygen.

Temperate grasslands

Praries of N. America shaped by cold winters, hot summers, wind, and fire.

Biotic Factors

Presence or absence of other species that are required for food or as pollinators or that parasitize or prey upon a species... or compete with that species. Ex. Sea Urchin. When sea urchins were removed from experimental plots in Sydney, Australia, seaweed cover increased dramatically, showing that urchins limited the distribution of seaweeds.

Primary/ Secondary growth in woody stem

Primary growth from the activity of the apical meristem is nearing completion. The vascular cambium has just formed. Although primary growth continues in the apical bud, only secondary growth occurs in this region. The stem thickens as the vascular cambium forms secondary xylem to the inside and secondary phloem to the outside. Some initials of the vascular cambium give rise to vascular rays As the vascular cambium's diameter increases, the secondary phloem and other tissues external to the cambium can't keep pace because their cells no longer divide. As a result, these tissues, including the epidermis, will eventually rupture. A second lateral meristem, the cork cambium, develops from parenchyma cells in the cortex. The cork cambium produces cork cells, which replace the epidermis. IN year 2 of secondary growth, the vascular cambium produces more secondary xylem and phloem, and cork cambium produces more cork. As the stem's diameter increases, the outermost tissues exterior to the cork cambium rupture and are slugged off. In many cases, the cork cambium reforms deeper in the cortex. When none of the cortex is left, the cambium develops from phloem parenchyma cells. Each cork cambium and the tissues is produces form a layer of periderm Bark consists of all tissues exterior to the vascular cambium.

Outline the Menstrual Cycle

Prior to ovulation, ovarian steroid hormones stimulate the uterus to prepare for support of an embryo. Estradiol secreted in increasing amounts by growing follicles signals the endometrium to thicken. After ovulation, the estradiol and progesterone secreted by the corpus luteum stimulate maintenance and further development of the uterine lining, including enlargement of arteries and growth of endometrial glands. These glands secrete a nutrient fluid that can sustain an early embryo even before it implants in the uterine lining. If an embryo has not implanted, the corpus luteum disintegrates. The resulting drop in ovarian hormone levels causes arteries in the endometrium to constrict. Deprived of its circulation, the uterine lining largely disintegrates, releasing blood that is shed along with endometrial tissue and fluid.

Hair Cells

Projecting from each hair cell is a bundle of rod-shaped "hairs" each containing a core of actin filaments. Vibration of the basilar membrane in response to sound raises and lowers the hair cells, bending the hairs against the surrounding fluid, and the tectorial membrane. Bending in one direction depolarizes hair cells, increasing neurotransmitter release and frequency of action potentials directed to the brain along the auditory nerve. Bending hairs in the other direction hyperpolarizes hair cells, reducing neurotransmitter release and the frequency of auditory nerve sensations

Erthrocytes

RBC's. Most numerous blood cell. O2 transport. Biconcave ++ Surface area, ++ rate of diffusion. Mature mammalian lack nuclei, leaving more space for hemoglobin. Lack mitochondria and generate ATP via anaerobic metabolism to not consume O2.

Why can ribosomes function as enzymes?

RNA is single stranded, and therefore may base-pair with complementary regions elsewhere on the same mlc, giving the mlc a 3d structure, which is essential to the catalytic function of ribozymes. Some of the bases in RNA contain functional groups that can participate in catalysis. The ability of RNA to hydrogen-bond with other nucleic acid molecules adds specificity to its catalytic activity.

How do ncRNAs remodel chromatin structure in yeast?

RNA transcripts are produced from centromeric DNA Each RNA transcript is used as a template by a yeast enzyme that synthesizes the complementary strand, forming double-stranded RNA. Double-stranded RNA is processed into short, single-stranded siRNAs that associate with proteins, forming siRNA-protein complexes. The siRNA-protein complexes bind the RNA transcripts being produced from eh centromeric DNA and tether to the centromere region Proteins in the siRNA-protein complexes recruit enzymes that chemically modify the histones within the chromatin and initiate chromatin condensation via methylation. This process leads to formation of heterochromatin at the centromere.

Electromagnetic receptor

Receptor that detects forms of electromagnetic energy, such as light, electricity, and magnetism. Ex: Platypus has electroreceptors on its bill that are thought to detect the electric field generated by the muscles of crustaceans, small fish, and other prey.

Chemoreceptor (general receptor)

Receptors that transmit information about total solute concentration

Albinism

Recessive

True-Breeding

Referring to organisms homozygous for the same allele and thus always produce offspring that are also homozygous for that allele.

Ultrasound

Reflected sound waves are used to produce an image of the fetus by a simple noninvasive procedure. Used to detect major anatomical abnormalities

Neuropeptides

Relatively short chains of amino acids, serve as neurotransmitters that operate via meabotropic receptors. Such peptide are typically produced by cleavage of much larger protein precursors.

Biodiversity hot spot

Relatively small area with numerous endemic species (found nowhere else in the world) and a large number of endangered/threatened species.

Outline the Ovarian Cycle

Release of GnRH from the hypothalamus, which stimulates the anterior pituitary to secrete small amounts of FSH and LH. Follicle starts to grow (FSH) and the cells of the growing follicle start to make estradiol (LH). The low levels of estradiol inhibit secretion of the pituitary hormones, keeping the levels of FSH and LH relatively low. When estradiol secretion by the growing follicle begins to rise steeply, the FSH and LH levels increase markedly, because high concentration of estradiol stimulates gonadotropin secretion by causing the hypothalamus to increase output of GnRH. High estradiol also increases the GnRH sensitivity of LH-releasing cells in the pituitary, resulting in a further increase in LH levels. In response to both FSH and the peak in LH level, the follicle and adjacent wall of the ovary rupture, releasing the secondary oocyte. LH stimulates the follicular tissue left behind in the ovary to transform into a corpus luteum. Under continued stimulation by LH, the corpus luteum secretes progesterone and estradiol, which in combination exert negative feedback on the hypothalamus and pituitary. This feedback reduces the secretion of LH and FSH to very low levels, preventing another egg from maturing when pregnancy may already be underway. IF PREGNANCY DOES NOT OCCUR: Low gonadotropin levels at the and of the luteal phase cause the corpus lutes to disintegrate, triggering a sharp decline in estradiol and progesterone concentrations. Decreasing levels of ovarian steroid hormones liberate the hypothalamus and pituitary from the negative feedback effect of these hormones. The pituitary can then begin to secrete enough FSH to stimulate the growth of new follicles in the ovary, initiating the next ovarian cycle. IF PREGNANCY DOES OCCUR: The implanted embryo secretes hormones that signal its presence and regulate the mother's reproductive system. One embryonic hormone, hCG, acts like pituitary LH in maintaining secretion of progesterone and estrogens by the corpus luteum through the first few months of pregnancy. Some hCG passes from the maternal blood to the urine, where it can be detected by the most common early pregnancy tests.

How do forensic scientists use STRs?

Repeated units of 2-5- nucleotide sequences in specific regions of the genome form genetic markers called STRs. The number of repeats present in these regions is highly variable from person to person (polymorphic). PCR is used to amplify particular STRs, using a set of primers that are labeled with different colored fluorescent tags; the length of the region, and thus the number of repeats, can then be determined by electrophoresis. Comparing the number of regions across suspects with DNA sample from the evidence can ID the perpetrator.

Postzygotic Barriers

Reproductive isolation after the hybrid offspring zygote is formed. Developmental errors may reduce survival among hybrid embryos, or problems after birth may cause hybrids to be infertile.

How do you assemble a functional Ig gene?

Requires rearranging the DNA. Early in B cell development, and enzyme complex called recombinase links one light chain V gene segment to one J segment. This recombination event eliminates the long stretch of DNA between the segments, forming a single exon that is part V, part J. Because there is only an intron between the J and C DNA segments, no further rearrangement of DNA is required. Instead, the J and C segments of the RNA transcript will be joined when splicing removes the intervening RNA. Recombinase acts randomly.

Hubbard Brook Experimental Forest

Research team collected rainfall at several sites to measure the amount of water and dissolved minerals added to the ecosystem. Constructed a dam with V-shaped spillways to monitor the loss of water. Found that about 60% of water added to ecosystem as rainfall/snow exits through the stream, and the remaining 40% is lost by evapotranspiration. Found that over 3 years, water runoff from the deforested watershed was 30-40% greater than in a control. Loss of nitrate, whose concentration in the creek increased 60-fold. The experiment showed that the amount of nutrients leaving an intact forest ecosystem is controlled mainly by the plants.

How do you use bacteria in DNA cloning?

Researches first obtain a plasmid and insert DNA from another source into it, creating a recombinant DNA molecule. The plasmid is then returned to a bacterial cell, producing a recombinant bacterium. This single cell reproduces through repeated cell divisions to form a clone of cells, a population of genetically identical cells. Because the dividing bacteria replicate the recombinant plasmid and pass it on to their descendants, the forge in DNA and any genes it carries are cloned at the same time.

What helps return blood to the heart from veins?

Rhythmic contractions of smooth muscles in the walls of venules and veins and by the contraction of skeletal muscles during exercise. Valves help ensure unidirectional flow.

Orgasm

Rhythmic, involuntary contractions of the reproductive structures in both sexes. Male first stage: Emission (glands and ducts of reproductive tract contract) Second stage: Expulsion (urethra contracts. Semen is expelled.

Difference in translation between Proks and Euks

Ribosomes begin translating mRNA even before its finished in Proks because there is no nuclear membrane

Ecological Significance of Fungi

Ripen blue cheese Eating truffles Used to produce alcohol. Compounds extracted from ergots is used to reduce high blood pressure and stop maternal bleeding after childbirth. Produce antibiotics that fight bacterial infections Penicillin comes from the mold ,Penicillium. Easy to culture/manipulate means they're often used in research for molecular genetics of eukaryotes. Can be genetically altered to produce human glycoproteins, including insulin-like GF. Thus holds potential to treat people with medical conditions that prevent them from producing certain compounds.

Primary root

Root originating in the seed embryo. First root/organ to emerge from a germinating seed.

Example of enantiomers

S-Ibuprofen (100x stronger) and R-Ibuprofen. R-Albuterol and S-Albuterol (cancels out R).

Standard Metabolic Rate

SMR; The metabolic rate of a fasting, non stressed ectotherm at rest at a particular temperature. (Lower energetic requirement than endotherms)

Spermathecae

Sac in the camel reproductive system of many insect species in which sperm may be stored for extended periods, a year or more in some species. Because the female releases male gametes from the spermathecae only in response to the appropriate stimuli, fertilization occurs under conditions likely to be well suited to embryonic development.

How do marine birds osmoregulate?

Salt glands above the eyes use active transport of ions to secrete a fluid much saltier than the ocean, allowing the marine vertebrate to achieve a net gain of water. As water runs through a central duct in the gland, salt ions are actively transported across transport epithelium into the secretory tubule. These tubules drain into central ducts leading to the nostrils.

How does the mark-recapture method work?

Scientists capture a random sample of individuals in a population, tag them, and then release them Scientists wait for the marked or otherwise identified individuals to mix back into the population (usually a few days or weeks) Scientists capture a second set of individuals The number of marked animals captured in the second sampling (x) divided by the total number of animals captured in the second sampling (n), should equal the number of individuals marked and released in the first sampling (s) divided by the estimated population size (N).

Why can natural selection not fashion perfect organisms?

Selection can act only on existing variations (meaning can't spontaneously inherit new advantageous alleles) Evolution is limited to historical constraints (must work with what you have. Adaptations are often compromises: Seals flippers (walking vs. swimming). Chance, natural selection, and the environment interact: Chance events doesn't transfer those best suited to new environments. Also, environment ma change at a particular year, limiting the extent to which adaptive evolution results in a close match between the organism and current environment.

r- Selection

Selection for life history traits that maximize productive success in uncrowded environments or disturbed environments. Ex. Traits such as semelparity and production of lots of small offspring at short intervals. Ex. Dandelions, insects, weeds

How is Barr Body formed?

Selection of which X chromosome will form the Barr body occurs randomly and independently in each embryonic cell present at the time of X inactivation. Inactivation of an X chromosome involves modification of the DNA and proteins bound to it, called histones, including attachment of methyl groups to DNA nucleotides. Two regions, one in each X chromosome, associate briefly with each other in each cell at an early stage of embryonic development. Then one of the genes, called XIST becomes active only on the chromosome that will become the Barr body. Multiple copies of the RNA product of this gene apparently attach to the X chromosome in which they are made, eventually almost covering it. Interaction of this RNA with the chromosomes initiates X inactivation, and the RNA products of other nearby genes help to regulate the process. As a consequence, females consist of a mosaic of two types of cells, those with the active X derived from the father, and those with the active X derived from the mother.

Intrasexual selection

Selection within the same sex: Individuals compete directly for mates of the opposite sex (ie. rams butting heads)

Mechanoreceptors

Sense physical deformation caused by forms of mechanical energy such as pressure, touch, stretch, motion, and sound. Typically consist of ion channels that are linked by structures that extend outside the cell, such as "hairs" (cilia) as well as internal cell structures, such as the cytoskeleton. Bending or stretching of the external structure generates tension that alters the permeability of the ion channels. Ex: Cats and rodents' whiskers

Primary structure

Sequence of amino acids. The precise primary structure of a protein is determined not by the random linking of amino acids, but by inherited genetic information.

Pheromones

Sexual signaling molecules released by hyphae from two mycelia to begin sexual reproduction.

Double helix

Shape of the two polynucleotides that make up DNA. The backbones run opposite 5' > 3' directions of each other, called antiparallel. The nitrogenous bases are paired in the interior of the helix. The two strands are held together by hydrogen bonds between paired bases. The two strands are called complimentary.

Origins of Replication

Short stretches of DNA having specific sequence of nucleotides.

R group

Side chain; differs with each amino acid.

Apical Surface

Side of epithelia that faces the lumen (cavity) or outside of the organ, and is therefore exposed to fluid or air.

How do siRNAs regulate affect mRNA?

Similar in size and function to miRNA- both can associate with the same proteins. The difference is in the structure of their precursors. Requires fully complementary binding in order for protein-complex to degrade target mRNA.

Monosaccharides

Simple sugars. The monomers from which more complex carbohydrates are built. Made up of a carbonyl group and multiple hydroxyl groups. Example: Glucose.

Polyandry

Single female + many male. ex. Red-necked phalaropes.

Polygyny

Single male + many female Ex: Elk. Lions.

What bonds are usually formed by carbon in organic molecules?

Single or double covalent bonds.

DNA Pol I

Single polypeptide with low processivity - leaves template strand after about 20 nukes and slow speed (10 nukes/sec). It replaces RNA primers with DNA nucleotides and therefore must have 5>3 exonuclease capability.

Phylogenetic species concept

Smallest group of individuals that share a common ancestor. Such analysis can distinguish groups of individuals that are sufficiently different to be considered separate species.

Example of Population cycles

Snowshoe hares undergo population cycles ever 10 years. When prey becomes scarce, predators often turn on one another, which is why the lynx follows the hare with population cycles: it is being killed by coyote as an effect.

How do proteins return to their functional shape?

Sometimes proteins may be able to return to their functional shape when the denaturing agent is removed, since the information for building a protein's specific shape is intrinsic to the primary structure.

Agnostic behavior

Somtimes ritualized competition for access to mates or territory between males Ex: Male Eastern Gray kangaroos hold boxing contests tht determine which male is most likely to mate with an available female.

Sympatric Speciation

Speciation occurs in populations that live in the same geographic area.

Advantages of seeds over spores?

Spores are usually single celled, whereas seeds are multicellular, consisting of an embryo protected by a layer of tissue, the seed coat. Seed can remain dormant for years after being released from the parent plant, whereas most spores have shorter lifetimes. Seeds have a supply of stored food, unlike spores. Most seeds land close to their parent sporophyte plant, but some are carried long distances by wind/animals. If conditions are favorable where it lands, the seed can emerge from dormancy and germinate, with its stored food providingg critical support for growth as the sporophyte embryo emerges as a seedling.

Moss life Cycle

Spores develop into threadlike protonemata (haploid) The haploid protonemata produce "buds" that divide by mitosis and grow into gametophores (haploid) Sperm must swim through a film of moisture to reach the egg from antheridia FERTILIZATION WITHIN ARCHEGONIUM The zygote develops into a sporophyte embryo (diploid) The sporophyte grows a long stalk (seta) that emerges from the archegonium (diploid) Attached by its foot, the sporophyte remains nutritionally dependent on the gametophyte (2n) Meiosis occurs and haploid spores develop in the capsule. When the capsule is mature, its lid pops off, and the spores are released.

Thick filaments

Staggered array of myosin molecules. Muscle contraction is the product of filament movement powered by chemical energy. Extension occurs only passively. Each myosin molecule has a long tail region and a globular head region.

Seta

Stalk; conducts the materials from the foot to the sporangium

Angiosperm roots (primary growth)

Stele is a vascular cylinder, consisting of a solid core of xylem and phloem tissues.

Chitin

Structural polysaccharide used by arthropods to build their skeletons. Embedded in a layer of proteins that is soft and flexible at first, but hardens when the proteins chemically link to each other, or become encrusted with calcium carbonate. β linkages.

Nonsense mutation

Substitution mutation that changes a codon for an AA into a stop codon.

What determines the architecture and function of a polysaccharide?

Sugar monomers and positions of its glycosidic linkages.

Evolutionary adaptations for increasing plants uptake of limiting nutrients

Symbiosis between plant roots and nitrogen-fixing bacteria. Mycorrhizal association between plant roots and fungi that supply phosphorus and other limiting elements to plants. Many plants release enzymes and other substances into the soil that increase the availability of limiting nutrients; such substances include phosphatases, which cleave a phosphate group from larger molecules and chelating agents that make micronutrients such as iron more soluble in the soil.

Translation

Synthesis of a polypeptide using the information in the mRNA

What is mRNA and what does it do?

Synthesized by each gene along a DNA molecule, messenger RNA interacts with the cell's protein-synthesizing machinery to direct production of a polypeptide.

Hershey Chase Experiment

Tagged T2 phage that infected E.coli bacteria with radioactive sulfur in one experiment and radioactive phosphorus in the next. The sulfur bound to the disulfide bonds in the tertiary structure of the phage's proteins. The phosphorus bound to the phosphate groups in DNA. Both tagged phages infected separate bacteria. Each batch was then but in a blender and centrifuged. The pellet of the sulfur-tagged phage experiment wasn't radioactive when measured with a ginger counter, suggesting protein had not made its way into the cell, while in the phosphorus tagged experiment, the pellet was radioactive, and the suspended liquid of phage parts above was not, suggesting the cell had taken up DNA. Thus, DNA was the carrier of genetic information, not proteins.

Knee jerk reflex

Tap the tendon connected to the quadriceps muscle Sensors detect a sudden stretch in the quads. Sensory neurons convey the information to the spinal cord. In response to signals from the sensory neurons, motor neurons convey signals to the quadriceps, causing it to contract and jerking the lower leg forward. Interneurons in the spinal cord receive signals from sensory neurons Motor neurons that lead to the hamstring are inhibited by the interneurons. This inhibition prevents contraction of the hamstring, which would resist the action of the quadriceps.

Hemizygous

Term that describes x-linked genes exhibited in males. Any male receiving the recessive allele from his mother will express the trait. Thus, sex-linked traits are more often expressed in the homozygous sex.

Refractory period

The "downtime" when a second action potential cannot be initiated, because the sodium channels remain inactivated during the falling phase and the early part of the undershoot.

Why does evaporative cooling occur?

The "hottest" molecules, those with the greatest kinetic energy, are the most likely to leave as gas, dropping the average kinetic energy in the remaining liquid's molecules, and thus the temperature.

Homeobox

The 180 base-pair sequence similar in all 8 homeotic genes. Homeotic genes with these homeoboxes are called Hox genes.

Wobble

The ability of 1 tRNA anticodon to bind to 2 or more mRNA codons (with only the third base differing). In many tRNA's with wobble the 3rd base of the anticodon is Inosine. The result is there are only about 45 tRNA's, not 61.

Developmental plasticity

The ability to alter form in response to local environments.

Associative learning

The ability to connect a stimulus with an outcome (bright red = sweet taste)

Specific heat

The amount of heat that must be absorbed or lost for 1g of that substance to change its temperature by 1°C.

Primary Production

The amount of light energy converted to chemical energy- in the form of organic compounds- by autotrophs during a given time period.

Stroke volume

The amt. of blood pumped by a ventricle in a single contraction.

How does the cochlea distinguish pitch?

The basilar membrane is not uniform along its length: it is relatively narrow and stiff at the base of th cochlea near the oval window and wider and more flexible at the apex. Each region of the basilar membrane is tuned to a different vibration frequency: shorter hairs along the basilar membrane are closer to the oval window, and detect higher pitches. Longer hairs closer to the apex detect lower pitches. Each region is connected by axons to a different location in the cerebral cortex. Consequently, when a sound wave causes vibration of a particular region of the basilar membrane, a specific site in our cortex is stimulated and we perceive the sound of a particular pitch.

Why is the trp operon not switched off permanently?

The binding of repressors to operators is reversible. The relative duration of the repressor bound and the operator without the repressor count state increases when there are more active repressor molecules present. The trp repressor is an allosteric protein, with two alternative shapes, and is synthesized in its inactive form, which has little affinity for a trp operator. Only when a tryptophan molecule binds to the trp repressor at an allosteric side does the repressor protein change its shape to active form.

Describe osmoregulation in a freshwater fish.

The body fluids of a freshwater fish must by hyper osmotic because animal cells cannot tolerate salt concentrations as low as that of lake or river water. Having internal fluids with an osmolarity higher than that of their surroundings, freshwater animals face the problem of gaining water by osmosis and losing salts by diffusion. These animals gain water and some ions in food, and uptake salt ions from their gills. Also, through the gills, there is an osmotic water gain. Lastly, excretion of salt ions and large amounts of water in dilute urine happens from the kidneys.

Homeodomain

The corresponding protein domain coded by a homeobox.

Ovarian Cycle

The cyclic changes in the uterus that occur in the ovaries.

Menstruation

The cyclic shedding of the blood-rich endometrium from the uterus, a process that occurs in a flow through the cervix and vagina.

Territoriality

The defense of a bounded physical space against encroachment by other individuals

Active Immunity

The defenses that arise when a pathogen infects the body and prompts a primary or secondary immune response.

Pattern formation

The development of a spatial organization in which the tissues and organs of an organisms are all in their characteristic places.

Pattern formation

The development of specific structures in specific locations

Morphogenesis

The development of the form of an organism and its structures

Conduction

The direct transfer of heat between molecules of objects in contact with each other

Describe the need for the lac operon

The disaccharide lactose is available to E. coli in the human colon if the host drinks milk. Lactose metabolism begins with the hydrolysis of the disaccharide into its component monosaccharides (glucose and galactose), a reaction catalyzed by the enzyme B-galactoside. Only a few molecules of this enzyme are present in an E. coli cell growing in the absence of lactose. If lactose is added to the bacterium's environment, however, the number of B-galactoside molecules in the cell can increase a thousandfold within about 15 minutes.

Solvent

The dissolving agent of a solution (doesn't dissolve)

Explain fungal food source diversity

The diversity of food soures corresponds to the varied roles of fungi in ecological communities: Decomposers, parasites, pathogens or mutualists.

RT-PCR

The enzyme reverse transcriptase is used in vitro to make a single stranded DNA reverse transcript of each mRNA molecule. The 3' end of the poly-A tail allows use of a short complementary strand of poly-dt as a primer for synthesis of a DNA strand. Following enzymatic degradation of the mRNA, a second DNA strand, complementary to the first, is synthesized by DNA polymerase. The resulting double-stranded DNA is called c-DNA, which contains no introns. To analyze the timing of expression of the fruit-fly gene of interest, first isolate all the mRNAs from different stages of Drosophila embryos and make cDNA from each stage. Then, use PCR to find any cDNA derived from the gene of interest.

Evapotranspiration

The evaporation of water from soil and plants. Accounts for sunlight and precipitation in communities.

Archegonia

The female gametangia. Each archegonium is a pear-shaped organ that produces a single nonmotile egg retained within the bulbous part of the organ. Each egg is fertilized within an archegonium, where the zygote develops into an embryo.

Lymph

The fluid lost by capillaries- composition is about the same as interstitial fluid.

Interstitial fluid

The fluid that fills the spaces between cells

Deoxy-chain termination sequencing

The fragment of DNA to be sequenced is denatured into single strands and incubated in a test tube with the necessary ingredients for DNA synthesis: a primer designed to base pair with the 3' end of the template strand, DNA polymerase, the four dNTPs and four ddNTPs, each tagged with a specific fluorescent molecule. Synthesis of each new strand starts at the 3' end of the primer and continues until a ddNTP happens to be inserted instead of the equivalent dNTP. The incorporation of the ddNTP prevents further elongation of the strand. Eventually, a set of labeled strands of every possible length is generated, with the color of the tag representing the last nucleotide in the sequence. The labeled strands in the mixture are separated by passage through a get that allows shorter strands to move through more quickly than longer ones. For DNA sequencing, the gel is in a capillary tube and its small diameter allows a fluorescence detector to sense the color of each fluorescent tag as the strands come through. Strands differing in length by as little as one nucleotide can be distinguished from each other.

Mycosis

The general term for an infection in an animal by a fungal parasite. Ex. Skin Myoses such as ringworm, chytrid infections that killed over 200 amphibian species Ex. Systemic Mycoses spreads throughout the body and usually causes severe illness. Caused by inhaled spores. Candida albicans inhabits moist epithelia, such as the vaginl lining. Under certain circumstances, Candida can grow too rapidly, and become pathogenic, leading to "yeast infections."

Osmoregulation

The general term for the precesses by which animals control solute concentrations and balance water gain and loss

Biosphere

The global ecosystem- the sum of all the planets ecosystems and landscapes.

Acclimatization

The gradual process by which an animal adjusts to changes in its external environment. This change is temporary during an animal's lifetime

Loop of Henle

The hairpin turn, with descending and ascending limbs, between the proximal and distal tubules of the vertebrate kidney; functions in water and salt reabsorption

Hyperpolarization

The increase in the magnitude of the membrane potential, which makes the inside of the membrane more negative (away from threshold). Results from any stimulus that increases the outflow of positive ions or the inflow of negative ions.

Convergent Evolution

The independent evolution of similar features in different lineages. Example: Australian sugar glider vs. Flying squirrel. Sugar glider more closely related to kangaroos and other Australian marsupials than to flying squirrels and other eutherians.

Perception

The integration of sensory system input by the brain. Examples: Colors, smells, sound, and tastes.

How can animals use Earth's magnetic field lines to riot themselves during migration?

The iron-containing mineral magnetite is found in many vertebrates, in bees, in some mollusks, and in certain protests and prokaryotes that orient to Earth's magnetic field.

Hemoglobin

The iron-containing protein that transports O2.

Coevolution

The joint evolution of two interacting species, each in response to selection imposed by the other. Ex. Most flowering plants have adaptations such as nectar or fruit that attract animals that pollinate flowers or disperse seeds. in turn, many animals have adaptations that help them find and consume nectar.

Thermal energy

The kinetic energy associated with the random movement of atoms or molecules.

Why are unsaturated fats usually liquid at room temperature?

The kins where the cis double bonds are located prevent the molecules from packing together closely enough to solidify at room temperature.

What is the cost of having more kids?

The larger the brood, the lower the survival rates of the parents, ESPECIALLY the male. Ex. Eurasian kestrels

Collecting Duct

The location in the kidney where processed filtrate, called urine, is collected from the renal tubules. As filtrate passes along the transport epithelium of the collecting duct, hormonal control of permeability and transport determines the extent to which the urine becomes concentrated. When eh kidneys are conserving water, aquaporins int he collecting duct allow water molecules to cross the epithelium. At the same time it remains impermeable to sale and, in the renal cortex, to urea. As the collecting duct traverses the gradient of osmoregularity the filtrate becomes increasingly concentrated, losing more and more water by osmosis to the hyper osmotic interstitial fluid.

Antheridia

The male gametangia. Each antheridia produces sperm and releases them into the environment. In many groups of present-day plants, the sperm have flagella and swim to the eggs through water droplets or a film of water.

Carrying Capacity

The maximum population size that a particular environment can sustain. Carrying capacity varies over space and time with the abundance of limiting resources. Energy, shelter, refuge from predators, nutrient availability, water, and suitable nesting sites can all be limiting factors.

Resting potential

The membrane potential for a resting neuron (not sending a signal). Typically between -60 and -80 mV.

Minimum viable Population

The minimal population size at which a species is able to sustain its numbers.

Describe muscle contraction

The myosin head is bound to ATP and is in its low energy configuration. The head hydrolyzes ATP to ADP and phosphate and is in its high energy configuration. In this configuration, the ehad binds to actin, forming a cross bridge. Releasing ADP and inorganic phosphate, myosin returns to its low energy configuration, sliding the thin filament. Binding of a new molecule of ATP releases the myosin fead from actin, and a new cycle begins.

Neurons

The nerve cells that transfer information within the body.

Postsynaptic cell

The neuron, muscle, or gland cell that receives a signal.

Leading strand

The new complementary DNA strand synthesized continuously along the template strand toward the replication for in the mandatory 5>3 direction.

Sapwood

The newest, outer layers of secondary xylem that still transport xylem sap

Ecosystem Diversity

The number and differences between ecosystems.

Species richness

The number of different species in the community

Density

The number of individuals per unit area or volume

Infant mortality

The number of infant deaths per 1k live births.

What are the biotic factors that influence the distribution/abundance of life on Earth?

The other organisms that are part of an individuals environment.

Renal cortex

The outer portion of the vertebrate kidney. Supplied with blood by a renal artery and drained by a renal vein. Within lie tightly packed excretory tubules ands associated blood vessels. Excretory tubules carry and process a filtrate. Nearly all of the fluid from the filtrate is reabsorbed into the surrounding blood vessels and exits the kidney through the renal vein. The remaining fluid leaves the excretory tubules as urine, is collected in the inner renal pelvis, and exits the kidneys via ureter.

Why must char gaff's rule be followed regarding DNA structure?

The pairing of a pyrimidine with a purine maintained the uniform diameter of the double helix, since a purine-purine pair was twice as wide as a pyrimidine-pyrimidine one. Also, A & T align to form 2 H bonds, while G and C form 3.

Epistasis

The phenotypic expression of a gene at one locus alters that of a gene at a second locus. Example: Coat color in Labrador Retrievers. 1 gene determines color. 1 gene determines whether the pigment will be deposited in the hair.

Dermal tissue system

The plant's outer protective covering. Forms the first line of defense against physical damage and pathogens.

Determination

The point at which an embryonic cell is irreversibly committed to becoming a particular cell type.

Life expectancy at birth

The predicted average length of life at birth.

How is evolution a process?

The process of evolution consists of the mechanisms that produce the observed pattern of change, representing the natural causes of the natural phenomena we observe.

DNA cloning

The production of multiple copies of a specific DNA segment

Relative abundance

The proportion each species represents of all individuals in the community.

What factors determine the number of species on an island?

The rate at which new species immigrate to the island and the rate at which species become extinct on the island.

Ribosomes

The sites of translation; molecular complexes that facilitate the orderly linking of amino acids into polypeptide chains.

Complete dominance

The situation in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable.

Small vs. declining pop approaches.

The small-population approach emphasizes smallness itself as an ultimate cause of population's extinction, especially through the loss of genetic Diversity. In contrast, the declining-population approach emphasizes the environmental factors that caused a population decline in the first place.

Dominant Species

The species that are the most abundant or that collectively have the highest biomass. Removing the dominant species can potentially have sever effects on other species, such as in the American Chestnut, which results in the extinction of seven species of moths/butterflies after most of its population was killed by the fungal disease chestnut blight.

Spines

The spines of cacti, such as the prickly pear, are actually leaves; photosynthesis is carried out by the fleshy green stems.

Petiole

The stalk of a leaf, which joins the leaf to a node of the stem. Grasses/other monocots lack petioles, and instead the base of the leaf forms a sheath that envelops the stem.

Organic chemistry

The study of compounds containing carbon.

What happens to most pentose and hexoses in aqueous solutions?

The sugar molecules form rings.

Deoxyribose

The sugar to which the nitrogenous base is attached in DNA. Lacks an oxygen atom on the second carbon in the ring.

Ecological Niche

The sum of a species' use of the biotic and abiotic resources in its environment.

Pangea

The supercontinent that formed around 250 million years ago, when plate movements brought all the land masses of Earth together

Describe Spring in lakes with winter ice cover'

The surface water warms to 4° C and mixes with the layers below, eliminating thermal stratification. Spring winds help mix the water, bringing oxygen to the bottom and nutrients to the surface.

Tendrils

The tendrils by which pea plants cling to a support are modified leaves. After it has "lassoed" a support, a tendril forms a coil that brings the plant closer to the support. Tendrils are typically modified leaves, but some tendrils are modified stems, as in grapevines.

Photopsins

The three visual pigments, red, greed, blue, that are formed from the binding of retinal to three distinct opsin proteins.

Vital capacity

The tidal volume during maximal inhalation and exhalation.

Gross Primary Production

The total primary production in an ecosystem; The amount of energy from light, or chemicals, converted to chemical energy of organic molecules per unit time.

Cross pollination

The transfer of pollen from an anther of a flower on one plant to the stigma of a flower on another plant of the same species. Enhances genetic variability.

Pollination

The transfer of pollen to the part of a seed plant that contains the ovules.

bioinformatics

The use of computer software to analyze large data sets, like the sequencing of an animal's genome.

Threshold

The value of membrane voltage as depolarization increases that starts an action potential.

Species Diversity

The variety of different kinds of organisms that make up the community

Species Diversity

The variety of species in an ecosystem or across the biosphere

Lateral meristems

The vascular cambium and cork cambium. These cylinders of dividing cells extend along the length of roots and stems.

Veins

The vascular tissue of leaves. Monocots have parallel major vein of equal diameter that run the length of the blade. Eudicots generally have a branched network of veins arising from a major vein that runs down the center of the blade.

Tidal volume

The volume of air inhaled and exhaled with each breath.

Greenhouse effect

The warming of Earth due to the atmospheric accumulation of carbon dioxide and certain other gases, which absorb reflected inferred radiation and reradiate some of it back toward Earth.

Why use bacterial plasmids as cloning vectors?

They can be readily obtained from commercial suppliers Can be manipulated to form recombinant plasmids by insertion of foreign DNA in a test tube They are easily reintroduced back into bacterial cells. Moreover, recombinant bacterial plasmids multiply rapidly owing to the high reproductive rate of their host cells.

Ground tissue system

Tissues that are neither dermal nor vascular. Includes cells specialized for functions such as storage, photosynthesis, support and short distance transport.

INclusive fitness

Total effect an individual's behavior has on helping its genes survive BOTH in its own offspring AND in offspring of close relatives.

Tracheids

Tracheids occur in the xylem of all vascular plants. Tube shaped cells that carry water and minerals up from the roots. Long, thin cells with tapered ends. Water moves from cell to cell mainly through the pits, where it does not have to cross thick secondary walls. Secondary walls hardened with lignin. This hardening provides support and prevents collapse under the tension of water transport.

What step is most commonly regulated during differentiation?

Transcription.

CML

Translocation during mitosis of cells that will become white blood cells, exchanging a large portion of chromosome 22 with a small fragment of chromosome 9 creates Philadelphia chromosome. This activates a gene that leads to uncontrolled cell cycle progression.

Sensory neurons

Transmit information about external stimuli such as light, touch, or smell, or internal conditions such as blood pressure or muscle tension.

Portal veins

Transport blood between paris of capillary beds.

Permease

Transport protein in membrane that allows lactose to enter cell easily

Operant conditioning

Trial and error learning Ex: Having a rat learn through trial and error how to obtain food (BF Skinner)

Klinefelter Syndrome

Trisomic Aneuploidy in male Sex chromosome - XXY. Testes abnormally small and man is sterile

Pyramid of Net Production

Trophic levels are arranged in tiers. Width is proportional to the net production, expressed in joules, of each trophic level.

Tubers

Tubers, such as these potatoes, are enlarged ends of rhizomes or stolons specialized for storing food. The "eyes" of a potato are clusters of axillary buds that make the nodes.

Double circulation in frogs and other amphibians

Two atria one ventricle. A ridge within the ventricle diverts most (90%) of the oxygen rich blood from the left atrium into the systemic circuit and most of the oxygen-poor blood from the right atrium into the pulmocutaneous circuit. The incomplete division of the ventricle allows the frog to adjust circulation underwater, shutting off must blood flow to the lungs.

Example explaining the difference between fundamental and realized niches.

Two barnacle species Chthamalus stellatus and Balanus balanoides have a stratified distribution on rocks along the coast of Scotland. The fundamental niche for both species is the entire rock. However, Chthamalus is usually found higher on the rocks than Balanus. To determine whether the distribution of Cthamalus is the result of interspecific competition with Balanus, ecologists removed Balanus from the rocks at several sites. As a result, Chthamalus spread into the region formerly occupied by Balanus. Thus, interspecific competition makes the realized niche of Chthamalus much smaller than its fundamental niche.

What is a beta barrel?

Two beta-like sheets packed tightly against each other and running antiparallel to each other in the domains of an immunoglobulin antibody molecule. Hydrogen bonding stabilizes the fold between the beta strands of each sheet, while van de Waals interactions bond residues of opposite sheets in the interior, and disulfide bonds bond between sheets.

Antigen Receptor (T Cell)

Two different polypeptide chains, a chains and B chain, liked by a disulfide bridge. Transmembrane region that anchors the molecule in the cell's plasma membrane. Variable (V) regions of the a and B chains together form a single antigen-binding site. Remainder of molecule is made up of Constant (C) regions.

Phospholipids

Two fatty acids attached to glycerol. Third hydroxyl group of glycerol is joined to a phosphate group, which has a negative electrical charge, and typically attracts an additional small charged or polar molecule to link to it, like Choline.

Disaccharides.

Two monosaccharides joined by a glycosidic linkage. Example: Maltose, sucrose, lactose.

Spatial summation of EPSP and IPSP

Two or more IPSP's occurring nearly simultaneously at synapses in the same region or in rapid succession at the same synapse have a larger effect than a single IPSP. Through summation, an IPSP can counter the effect of an EPSP.

β pleated sheet

Two or more segments of the polypeptide chain lying side by side (called β strands) are connected by hydrogen bonds between parts of the two parallel segments of the polypeptide backbone. Make up the core of many globular proteins.

Binomial

Two part format of the scientific name. First part is genus. Second is specific epithet (species.

Fusion

Two species contact one another in a hybrid zone, but the barriers to reproduction are not strong. So much gene flow may occur that reproductive barriers weaken further and the gene pools of the two species become increasingly alike. Eventually, two hybridizing species fuse into a single species. Ex. Cichlids

What could possible explain Dolly's premature death?

Two things could possible explain Dolly's premature death: the length of the telomeres in the mammary cell nucleus, and methylation of DNA and chromatin structure. First, because the nucleus from the mammary cell was formed after differentiation, and thus as the result of mitosis, shortened telomeres at the end of replicated DNA strands meant that Dolly's DNA could've started degrading sooner than usual, for its nucleus was closer to the Hayflick limit. Second, since the nucleus came out of differentiated cells, the Chromatin/DNA was already methylated to aid the specific function of the mammary cells. These methylated groups could've caused problems during embryonic development and cell differentiation, for the wrong segments for certain cells would've already been condensed or spread apart.

Semiconservative model

Type of DNA replication in which the replicated double helix consists of one old strand, derived from the parental molecule, and one newly made strand.

Fibers

Type of Sclerenchyma cell. Usually grouped in strands, are long, slender, and tapered. Some are used commercially, such as hemp fibers for making robe and flax fibers for weaving into linen.

Cholesterol

Type of steroid. Common component of animal cell membranes and the recourse from which other steroids, such as sex hormones, are synthesized. Invertebrates, cholesterol in synthesized in the liver and obtained from the diet.

Changes in UbX genes?

UbX gene expressed in abdomen in insects but main trunk of body in crustaceans. Fly gene suppresses 100% of limbs in embryos. Artemia Gene only 15%. RESEARCHERS made mutant Ubx with segments of drosophila and artemis genes. Inserted those genes into fruit fly embryos and by observing their effects on leg development researchers were able to pinpoint the exact amino acid changes responsible for the suppression of additional limbs on insects.

Bioremediation

Using organisms, usually prokaryotes, fungi, or plants- to detoxify polluted ecosystems

Thermogenesis

Varying heat production to match changing rates of heat loss in endotherms (shivering) because body temp is considerably higher than environmental temp. Certain hormones can cause mitochondria to increase metabolic activity and produce heat instead of ATP (non shivering thermogenesis). Brown fat is specialized for rapid heat production.

Vascular tissue of stems in eudicots

Vascular bundles arranged in a ring. The xylem in each vascular bundle is adjacent to the pith, and the phloem in each bundle is adjacent to the cortex. Stems consist mostly of parenchyma.

Vascular tissue of stems in monocots

Vascular bundles scattered throughout the ground tissue rather than forming a ring. Stems consist mostly of parenchyma.

Monocot roots (primary growth)

Vascular tissue consists of a central core of unspecialized parenchyma cells surrounded by a ring of alternating xylem and phloem tissues.

Xylem

Vascular tissue that conducts most of the water and minerals upward from roots into the shoots. Includes tracheas, and lignified.

Phloem

Vascular tissue with cells arranged into tubes that distribute sugars, amino acids, and other organic products, from where they are made (leaves) to where they are needed (roots/sites of growth, such as developing leaves and fruits).

What two types of physiological reactions predominate in both sexes during arousal?

Vasocongestion, and myotonia (increased muscle tension).

Antidiuretic Hormone (ADH)

Vaspressin; Binding of ADH to receptor molecules in collecting duct membranes leads to a temporary increase in the number of aquaporinproteins inserted in the membrane. The result is that the epithelium of the collecting ducts in the kidney is more permeable to water. The resulting increase in water reabsorption concentrates urine.

What maintains the partial pressure gradients of O2 and CO2 across the gill that are necessary for gas exchange?

Ventilation., coordinated by movements of the mouth and gill covered.

Double circulation in alligators, caimans, and other crocodilians

Ventricles are divided by a complete septum, but the pulmonary and systemic circuits connect where the arteries exit the heart. Connection allows arterial valves to shunt blood flow away from the lungs temporarily.

Mast cells

Vertebrate body cells that produce histamine and other molecules that trigger inflammation in response to infection and in allergic reactions.

Smooth muscle

Vertebrates; Walls of hollow organs. Lack striations because their actin and myosin filaments are not regularly arrayed along the length of the cell. Thick filaments are instead scattered throughout the cytoplasm, and the thin filaments are attached to structures called dense bodies. Less myosin than in striated muscles, and the myosin is not associated with specific actin strands. No troponin complex or t tubules.

Microclimate

Very fine, localized patterns, such as those encountered by the community of organisms that live in the microhabitat beneath a fallen log.

Species Selection

View species as analogous to individuals: Speciation is brith, extinction is death, new divergences are offspring. The species that endure the longest and generate the most new offspring species determine the direction of major evolutionary trends.

Mucus

Viscous fluid that traps pathogens and other particles.

Leukocytes

WBC's

What makes up plasma?

Water (solvent), Ions (osmotic balance, pH buffering, regulation of membrane permeability), plasma proteins (antibodies + fibrinogen to help clot.), substances transported by blood.

What happens to water between 4 and 0° C?

Water begins to freeze because more and more of its molecules are moving to slowly to break hydrogen bonds.

What does water dissolve?

Water can dissolve many ionic compounds and many small molecules that have enough polar bonds to form lots of Hydrogen Bonds with water molecules. Water can NOT dissolve non-polar molecules with which it can form no Hydrogen bonds.

What happens to water at 0° C?

Water molecules becomes locked into a hexagonal, crystalline lattice, with each water molecule hydrogen-bonded to four partners (as opposed to the average of 3.4 Hydrogen bonds per molecule in liquid form), moving the molecules farther apart, and increasing the volume of the water, making it less dense.

Fungi as decomposers

Well adapted decomposers of cellulose and lignin. Almost any carbon-containing substrate.

Even IF a primer can be build at the very end of a DNA molecule's 3' end, that primer can't be replaced by DNA pol I since there is no platform for the DNA pol to wrk from once the primer is removed. Thus the end of that strand will be shorter when the DNA replicates next time, and it ill get shorter each replication cycle.

What is the fundamental problem with eukaryotes with linear DNA molecules?

Reproductive Isolation

What the formation of a new species is dependent on; the existence of biological factors that impede members of two species from interbreeding and producing viable, fertile offspring.

Phagocytosis

When a cell ingests/ breaks down bacteria and other foreign substances.

Behavioral Responses

When an animal is cold, goes warm. When warm, they bathe, move to cool areas, turn in a different direction, minimizing absorption of heat from the sun. Honeybees huddle in cold weather, and transport water to the hive and fan it with their wings in warm weather to promote evaporation and convection.

How do horizontal cells work? Lateral inhibition.

When an illuminated rod or cone stimulates a horizontal cell, the horizontal cell inhibits more distant photoreceptors and bipolar cells that are not illuminated. The result is that the region receiving light appears lighter and the dark surroundings even darker. The result is increased contrast sharper edges.

Primary succession

When ecological succession begins in a virtually lifeless area where soil has not yet formed. Soil develops gradually as rocks weather and organic matter accumulates from the decomposed remains of the early colonizers. Early arrivals may facilitate the appearance of the later species by making the environment more favorable (ie. increasing fertility of soil) Ex. New species found on volcanic island or on the rubble left by a retreating glacier.

Spawning

When individuals clustered in the same area release their gametes into the water at the same time. Chemical signals that one individual generates in releasing gametes trigger others to release gametes. Environmental cues can also cause a whole population to release gametes.

How do behavior and habitat limit the distribution of species?

When individuals seem to avoid certain habitats, even when the habitats are suitable, the organism's distribution may be limited by habitat selection behavior. Ex. Many females lay eggs only in response to specific env. cues; if those cues are missing, eggs may not be laid.

Facilitation

When species have positive effects (+/+ or 0/+) on the survival and reproduction of other species without necessarily living in the direct and intimate contact of a symbiosis. Ex. Black rush Juncus gerardii makes the soil more hospitable for other plant species in some zones of new England Salt marshes. Juncus helps prevent salt buildup in the soil by shading the soil surface, which reduces evaporation.

Turnover

When temperate lakes undergo a semiannual mixing of their waters as a result of changing temperature profiles. This turnover sends oxygenated water from the lakes surface to the bottom and brings nutrient-rich water from the bottom to the surface in both spring and autumn.

Dikaryotic

When the haploid nuclei in a mycelium pair off two to a cell, one from each parent. As a dikaryotic mycelium grows, the two nuclei in each cell divide in tandem without fusing. Because these cells retain two separate haploid nuclei, they differ from diploid cells, which have pairs of homologous chromosomes within a single nucleus.

Denaturation

When the weak chemical bonds and interactions within a protein are destroyed due to changes in environment. Most proteins become denatured if they are transferred from an aq. environment to a nonpolar solvent. Other denaturation agents include chemicals that disrupt hydrogen bonds, ionic bonds, and disulfide bridges. Denaturation can also result from excessive heat, which can overpower the weak interactions that stabilize the structure.

Triacylglycerol

When three fatty acids are joined to a glycerol by an ester linkage.

Biological Magnification

When toxins are more harmful because they become more concentrated in successive trophic levels of a food web. Occurs because the biomass at any given trophic level is produced from a much larger biomass ingested from the level below.

Temporal Summation

When two EPSP's occur at a single synapse in such rapid succession that the postsynaptic neuron's membrane potential has not returned to the resting potential before the arrival of the second EPSP.

How does carbon create a molecule in which the atoms are coplanar?

When two carbons are joined by a double bound (ex. Ethene), the bonds from both carbons are all in the same plane.

Isoosmotic

When two solutions have the same osmolarity. Water molecules will continually cross the membrane at equal rates in both directions, meaning no net movement of water by osmosis.

Antigenic drift

When variation shows in the epitope regions of viruses.

Recruitment of natural killer cells in adaptive immune response

When virus takes over a host, it produces viral proteins that appear on the cell surface. If antibodies specific for epitopes on these viral proteins bind to the exposed proteins, the presence of bound antibody at the cell surface can reguit a natural killer cell to release proteins that cause the infected cell to undergo apoptosis.`

Mountains effect on climate

When warm, moist air approaches a mountain, the air rises and cools, releasing moisture on the windward side of the peak. One the leeward side, cooler, dry air descends, absorbing moisture and producing a "rain shadow." Mountains also affect the amount of sunlight reaching an area and thus the local temperature and rainfall. South-facing slopes in the Northern hemisphere receive more sunlight than north-facing slopes and are therefore warmer and drier. These physical differences influence species distributions locally. IN addition, ever 1k meter increase in elevation produces and average temp. drop of 6° C.

How do we detect when our head is tilted?

When you tilt your head, the otoliths press on the hairs protruding into the cupula gel. The hair cell receptors transform this deflection into a change in the output of sensory neurons, signaling the brain that your head is on an angle. Three fluid filled semicircular canals connected to the utricle detect turning of the head and other rotational acceleration. Because the three canals are arranged in the three spatial planes, they can detect angular motion of the head in any direction.

Specific Transcription factors

When, in eukaryotes, high levels of transcription of particular genes at the appropriate time and place depend on the interaction of control elements with another set of proteins, called specific transcription factors.

Lymphocytes

White Blood Cells that originate from stem cells in the bone marrow, and mediates immune responses. Two main classes are B and T cells.

Ultimate causation

Why a behavior occurs

DNA pol II must be able to remove and replace misfired nucleotides; this is no problem if nukes are added to 3' end, BUT if nukes are added to the 5' end (triphosphate end) and then removed, then since the pyrophosphate is already gone, no new nukes could be added, for it lacks an energy source. A ligase-like enzyme would be too slow.

Why does DNA polymerase III only add to the 3' end?

The first few bases may have a very high error rate; thus, a replication system that can recognize these bases and remove and replace them later may be favored.

Why must DNA pol III have that RNA primer to begin?

Walls of Veins

Wider innermost endothelium layer, with valves, then smooth muscle, then connective tissue. Walls not as thick because veins convey blood back to the heart at a lower pressure.

Wood development in temperate regions, seasonally

Wood that develops early in the spring, known as early wood, usually has secondary xylem cells with large diameters and thin cell walls. This structure maximizes delivery of water to leaves. Wood produced later in the growing season is called late (or summer) wood. It has thick walled cells that do not transport as much water but provide more support.

Thomas Malthus

Wrote an essay that contended much of human suffering- disease, famine, war- resulted from the human population's potential to increase faster than food supplies and other resources.

Duchenne muscular dystrophy

X-Linked disorder which affects about 1/3500 males born in the US. Absence of a key muscle protein called dystrophin in the X chromosome. Characterized by a progressive weakening of the muscles and loss of coordination. Affected individuals rarely live past their early 20s.

Name some methods that can show the 3d structures of proteins

X-Ray crystallography, Nuclear magnetic resonance spectroscopy, bioinformatics.

Hemophilia

X-linked recessive disorder defined by the absence of one or more of the proteins required for blood clotting.

Are the functions of proteins emergent properties?

Yes, the function of a protein is dependent on its shape, which is dependent on the sequence of amino acid chains in the polypeptide.

What problems are associated with an aging population with few young people and children?

Young people will need to support more old people in the future, making Medicare and Social Security a larger topic.

Zone of differentiation

Zone of maturation; cells complete their differentiation and become distinct cell types.

Zones of primary growth in roots

Zones of cell division, elongation, and differentiation.

What is the product of the H⁺ and the OH⁻ concentrations in any aqueous solution at 25°C?

[H⁺][OH⁻] = 10⁻¹⁴

What positive regulation does the breakdown of lactose in E. coli use?

cAMP accumulates when glucose is scarce. The regulatory protein, CAP, is an activator. When cAMP binds to CAP, CAP assumes its active shape and can attach to a specific site at the upstream end of the lac promoter. This attachment increases the affinity of RNA polymerase for the promoter, which is actually rather low even when no repressor s bound by the operator. By facilitating the binding of RNA polymerase to the promoter, and thereby increasing the rate of transcription, the attachment of CAP to the promoter directly stimulates gene expression.

What happens to CAP when the amount of glucose in the cell increases?

cAMP concentration falls, and without cAMP, CAP detaches from the operon. Because CAP is inactive, RNA polymerase binds less efficiently to the promoter, and transcription proceeds only at a low level.

Logistic Population Growth model equation

dN/dt = r(inst)N * (K-N)/K

How often does DNA's double helix make a full turn?

every 3.4 nm along its length

How do miRNAs affect mRNA?

niRNAs are capable of binding to complementary sequences in mRNA molecules. A longer RNA precursor is processed by cellular enzymes into an miRNA, a single stranded RNA of about 22 nucleotides that forms a complex with one or more proteins. The miRNA allows the complex to bind to any mRNA molecule with at least 7-8 nucleotides of complementary sequence. The miRNA-protein complex either degrades the target mRNA or blocks its translation.

How do you represent a locus with two alleles?

p represents frequency of 1 allele, and q the other

Explain production of small regulatory RNA molecules and RNAi

siRNAs are derived from longer, double-stranded RNAs produced either in the cell itself, or delivered into the cell experimentally. miRNAs come from RNAs transcribed in the nucleus, which then fold and are processed before being exported into the cytoplasm as double-stranded precursor miRNAs The double-stranded precursors of miRNAs and siRNAs bind to Dicer, an endonuclease protein that cuts the RNA into short, usually 21-nucleotide long segments. The short, double stranded RNAs then bind to an Argonaut protein. One strand of the RNA is selected and remains bound to Argonaut. This strand is named the guide strand. The combination of the RNA and Argonaut, along with other proteins, is called the RNA induced silencing complex, or RISK. siRNAs direct RISK to bind to specific mRNAs. The targeting is precise because its determined by base pairing between the si RNA and the target mRNA. siRNAs often have perfect complementarity to their sites. Once bound, Argonaut catalyzes cleavage of the mRNA, which will then degrade. miRNAs also guide RISK to mRNAs, but only need part of the miRNA, the seed, to bind to the target mRNA sequence. This imprecise binding allows miRNA to target hundreds of endogenous mRNAs. Targeting by an miRNA can lead to mRNA to be degraded or translation be inhibited. Argonauts and their small, regulatory RNA cofactors are found in plants, animals, fungi, and some bacteria.

t variable

time

Support for Endosymbiont Theory?

• Inner membranes of both organelles have homologous enzymes and transport systems to those found in plasma membranes of living prokaryotes. • Mitochondria and plastids replicate by a splitting process that is similar to certain prokaryotes. • Each organelle contained circular DNA, which are not associated with histones or large amounts of other proteins. • RNA sequences and sensitivity to certain antibiotics, the ribosome of mitochondria and plastids are more similar to prokaryotic ribosomes than they are to the cytoplasmic ribosomes.