Biology 2 Unit 1

Symbiosis

is an intimate relationship between partners of two or more species

artificial selection

many varieties of plants and animals could be developed in just a few generations

Which reproductive isolation mechanism explains why a large dog, such as a Newfoundland, would not normally mate with a small dog, such as a Chihuahua?

mechanical isolation

Pili

are appendages that are longer (and fewer) than fimbriae

Serial endosymbiosis hypothesis

assumes certain organelles arose from symbiotic relationships between larger cells and smaller bacteria incorporated to live within them

Phototrophs

capture energy from light

Spherical:

cocci (coccus) Occur singly, in groups of twos (diplococci),in long chains (streptococci), or clumps (staphylococci)

Some protists consist of a single cell with multiple nuclei. This condition is known as:

coenocytic

Which algal group contains individuals that are typically unicellular and form siliceous shells?

diatoms

Chromalveolates•Alveolates

dinoflagellates, apicomplexans, and ciliates

Transformation

A bacterial cell takes up fragments of foreign DNA (or RNA) released by another bacterium, exchanges DNA, resulting in a recombinant cell

Diatoms

Stramenopiles with shells composed of two parts•Cell wall consists of two overlapping silica shells with radial or bilateral symmetry•Some are plankton; others live on rocks or sediments

allopatric speciation

evolution of genetic reproductive barriers between populations that are geographically separated by a physical barrier

inbreeding increases the

frequency of homozygous genotypes

Conjugation

Two cells of different mating types come together; genetic material is transferred

habitat isolation

Two closely related species in the same geographic area live and breed in different habitats in that area

Gene transfer results in

genetic recombination

Zea mays is the scientific name of the corn plant. Zea represents the:

genus

the sum of all genotype frequencies

1.0

When faced with multiple possible cladograms, the criteria of ____ can be employed to pick the "best" hypothesis.

parsimony

Which hypothesis asserts that viruses are remnants of cellular organisms and evolved from small cells that were parasites in larger cells?

regressive hypothesis

if two alleles are dominant and recessive, the dominant phenotype is

the sum of two genotypes (AA and Aa)

Stramenopiles

water molds, diatoms, golden algae, and brown algae

viral reassortment leads to

rapid evolution

mutation

unpredictable change ion DNA

the first cells

vesicle like protobionts they divide by binary fission they maintain homeostasis some show beginnings of metabolism they are highly organized

Aristole

visualized organisms as 'moving toward a more perfect state' -- scale of nature

single stranded rna may have evolved into a more stable double stranded dna

DNA became information storage and rna remained involved in protein enzymes catalyzed most cell reactions

Four of the following ideas are consistent with Darwinian evolution. Which one is the exception?

Traits acquired during an individual's life are passed on to its offspring.

Under which mating condition is the Hardy-Weinberg principle applicable?

Matings between individuals are random.

What type of organism possesses multiple sets of chromosomes from different species?

an allopolyploid

An example of homologous structures is the wing of a bat and the:

arm of a human.

Alfred Wallace

arrived at the same conclusion at the same time as Darwin - Contributions to the Theory of Natural Selection

Prokaryotes reproduce

asexually

most viruses do not cause

disease

temperate viruses

do not always destroy host

Members of the alveolates are characterized by the presence of:

flattened vesicles under the plasma membrane

What best describes all of the alleles for all the loci present in a population?

gene pool

Black bears and brown bears co-occur but black bears spend their time in the woods and brown bears along the river. Which of the following best describes why they don't interbreed?

habitat isolation

diploid organisms

have two alleles at each genetic locus

macroevolution

involved large scale evolutionary changes

autotrophy

self feeding

Darwins four observations on the natural world

variation, overproduction, limits on population growth, differential reproductive success

Membership in a clade cannot be established by shared ancestral traits alone.

True

shortcomings of biological species concept

applies only to sexually reproducing organisms

What process has been used to produce many of today's vegetables, such as broccoli, kohlrabi and cauliflower, which are all derived from wild cabbage?

artificial selection

Mutualism

both partners benefit

macroevolution

changes among species over long periods

The surface of a Paramecium is covered with thousands of short, hair-like ____.

cilia

The bacterium that causes botulism disease is harmless until it:

contains a certain prophage DNA.

The most common outcome in interspecific hybrid offspring is no viable gametes. This happens because of:

defective meiosis

If allele frequencies do change over successive generations,

evolution is occurring

q2

frequency of aa

first cells were

heterotrophs

extreme halophiles

heterotrophs that require large amounts of na for growth

gemetic isolation

if mating takes place, molecular and chemical differences between species prevents fertilization

Variation

individuals in a population exhibit variation in traits; some improve an individuals chances of survival and reproductive success

Diplomonads

Excavates with one or two nuclei, no functional mitochondria, no Golgi complex, and up to eight flagella

genus

First part of scientific name.

Which is an example of adaptive radiation?

Four flowers of different species that evolved from a common ancestor due to selective pressures in slightly different niches

Unlike DNA in eukaryotic chromosomes, prokaryote DNA has

little protein

alveolates

dinoflagellates, apicomplexans, ciliates flattened vesicles inside plasma membrane

Nuclear area:

nucleoid

Commensalism

one partner benefits and the other is neither harmed nor helped

The specificity of viruses to different types of cells is due to ____ sites on the host cell.

receptor

Virus-first hypothesis

states that viruses predate cellular hosts. Viruses originated in a precellular world and were the first self-replicating entities

Which of the following can produce a population of individuals with a relatively high frequency of a harmful or rare allele?

the founder effect

species concepts

the morphological or phenetic species concept: into separate species based on their visible structural difference

An example of homoplastic structures is the wing of a butterfly and:

wing of a bird.

If an animal population is diploid, then each individual possesses:

two alleles for each locus.

Progressive hypothesis

viruses are mobile genetic elements that have evolved the added ability to escape from the cellular genome (escape hypothesis)

Five "informal" supergroups

Excavates •Chromalveolates •Rhizarians •Archaeplastids •Unikonts

A(n) paraphyletic group consists of several evolutionary lines that do not share a common ancestor.

False

If the allele or genotype frequencies deviate from the values predicted by the Hardy-Weinberg principle, the population is:

evolving.

Gram-negative bacteria

do not retain the stain

Which classification level contains the greatest number of species?

domain

Suppose a gene is transferred naturally by a bacterium from a plant genome to an insect genome within the same generation. What process does this illustrate?

horizontal gene transfer

viruses replicate inside

host cells

parapatric speciation

involved spatially distinct populations, between which there is gene flow, diverge and become reproductively isolated

Which is the only process that can lead to adaptations and directed genetic change of a population?

natural selection

Binary fission

one cell divides into two similar cells in which circular DNA replicates, then an ingrowth of plasma membrane and the cell wall forms a transverse wall

A taxon that diverges earlier and is sister to the other taxa being considered in cladistic analysis is a(n):

outgroup

Three Domains

Bacteria, Archaea, Eukarya

what is a population

a group of individuals of one species that live in the same geographic area at the same time

The term "clade" most closely refers to:

a group of organisms that share common characteristics inherited from a common ancestor.

At what stage of the lysogenic cycle would a prophage appear?

integration

Allopatric speciation is often exemplified in which type of geographical area or biome?

islands

Which best describes a population that forms a new species within the same geographical region as the original species?

sympatric speciation

Chromalveolates

A supergroup composed of extremely diverse protists with few shared characters •Probably originated by secondary endosymbiosis in which an ancestral cell engulfed a red alga •Most are photosynthetic •Include alveolates and stramenopiles •Contain alveoli (flattened vesicles) •Similar rDNA sequences

At what stage of the lysogenic cycle would a prophage appear?

Integration

enveloped virus

Virus that cannot infect other cells without a coat (envelope). If the envelope is destroyed (e.g., by heat or soap and water) it is unable to produce infection. Ex.

zooxanthellae

photosynthetic endosymbionts in marine invertebrates, such as corals

modes of selection

stabilizing, directional, disruptive

prezygotic barriers

Barriers that impede mating or hinder fertilization.

postzygotic barriers

Barriers that prevent the hybrid zygote from becoming a fertile adult. if an interspecific hybrid lives it may not reproduce

Parabasilids are excavates that lack functional mitochondria and lack a Golgi complex.

False

Excavates

Group of unicellular protists with flagella and a deep (excavated) oral groove Have atypical, greatly modified mitochondria •Many are endosymbionts and live in anoxic environments •Obtain energy by glycolysis (anaerobic) •Include diplomonads, parabasalids, euglenoids, and trypanosomes

Brown Algae

Largest and most complex of all seaweeds; sizes range from a few centimeters to 75 m

the binomial system

Linnaeus, naming organisms according to genus and species

One critical requirement for life to arise on Earth was time for which to occur?

Molecules to accumulate and react with one another

Methods of obtaining nutrients differ widely among protists

Most algae are autotrophic photosynthesizers •Some heterotrophs obtain nutrients by absorption •Some heterotrophs ingest food •Some protists switch their modes of nutrition and are autotrophic at certain times and heterotrophic at others

Fermentation

Process by which cells release energy in the absence of oxygen

convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

Why is it believed that RNA was the first informational molecule to evolve?

RNA molecules are able to function as both enzymes and substrates for their own replication.

How do retroviruses differ from other RNA viruses?

Retroviruses have reverse transcriptase instead of RNA-dependent RNA polymerase.

Most protists are motile

Some move by pushing out cytoplasmic extensions (pseudopodia) along the leading edge •Others move by flexing individual cells; gliding over surfaces; waving cilia or flagella

_________ is the scientific study of the diversity of organisms and their evolutionary relationships.

Systematics

primary endosymbiosis

The engulfment of a cyanobacterium by a larger eukaryotic cell that gave rise to the first photosynthetic eukaryotes with chloroplasts.

sympatric speciation

The evolution of reproductive barriers within a single initially randomly mating population between two populations in the same geographic range change in ecology and ploidy

q= frequency of the recessive allele

a

prebiotic soup

a hypothetical solution of sugars, amino acids, nitrogenous bases, and other building blocks of larger molecules that may have formed in shallow waters or deep-ocean vents of ancient Earth and given rise to larger biological molecules

prions

a normally harmless protein (prp) sometimes fold into a different shape that causes disease

Evolution is genetic change in ____ that occurs over time.

a population

Which are evolutionary modifications that improve the survival and reproductive success of an organism?

adaptations

To cause disease, a pathogen must be

adapted to adhere to a specific cell type, multiply, and produce toxic substances (exotoxins)

oxygen poisoned obligate anaerobes

aerobic respiration evolved that used oxygen to increase the amount of energy extracted from food -- stabilized oxygen and carbon dioxide levels

behavorial isolation

also known as sexual isolation, many animal species exchange a distinct series of signals before mating

Adaptation

an evolutionary modification that improves the chances of survival and reproductive success in a given environment

Which type of protist is responsible for malaria in humans, parasitic to both humans and mosquitoes?

apicomplexans

bacteriophages infect

bacteria

Which protist group is characterized by having a micronucleus and a macronucleus?

ciliates

Phylogenetic systematics produce branching diagrams called:

cladograms

polyphyletic group

consists of several evolutionary lines that do not share the same recent common ancestor

Genetic equilibrium exists only when these conditions are met

diploid organisms, large population size random mating no natural selection no overlapping generations no net mutations no migrations

When phenotypes are favored at one extreme of a normal distribution, ____ selection occurs.

directional

Protists

eukaryotes that cannot be classified as animals, plants, or fungi mostly aquatic

2pq

frequency of Aa

founder effect

genetic drift that results when a few individuals from a large population found a new colony

Zea mays is the scientific name of the corn plant. Zea represents the:

genus.

taxon

group or level of organization into which organisms are classified

Prokaryotic cells do not

have a nucleus or other membrane-enclosed organelles

Most multicellular protists

have relatively simple body forms without specialized tissues

shared traits from a common ancestor are

homologous traits

iron-sulfur world hypothesis

hypothesis that the metabolic reactions that led to the first cells took place on the porous surface of iron-sulfide-rich rocks at hydrothermal vents

differential reproductive success

individuals with the most favorable combination of characteristics are more likely to survive and reproduce

postzygotic barriers

isolating barriers that act after a zygote begins to develop

natural selection changes allele frequiencies

member of a population that are better adapted to the environment have greater fitness- are more likely to survive and reproduce over generations, the proportion of favorable alleles increases in the population

A taxon that includes all the descendants of an ancestor is called:

monophyletic

A taxon that includes all the descendants of an ancestor is called:

monophyletic.

What is the only source of all new alleles in a closed (isolated) population?

mutation

there are five microevolutionary processes

nonrandom mating mutation genetic drift gene flow natural selection

Parasitism

one partner lives on or in the other; the parasite benefits and the host is harmed

Aerobic bacteria require

oxygen for cellular respiration

uv protection

oxygen reacted to form ozone layer organisms could live closer to land and not always in/around water

Given the diversity in protist ultrastructure and molecular data, biologists regard the protists as a(n) ____ group, meaning that some are descendants of a common eukaryote ancestor.

paraphyletic

a populations gene pool includes all the alleles for all the loci

present

Temporal and habitat isolation is classified as what type of reproductive barrier?

prezygotic barriers

The Hardy-Weinburg Principle

principle that allele frequencies in a population will remain constant unless one or more factors cause it to change.

The five stages of a lytic infection are attachment, penetration, __________, assembly, and release.

replication

node

represents the divergence of two or more groups from a common ancestor

In ____ selection, individuals with a phenotype near the mean are favored over those at the phenotypic extremes.

stabilizing

first cells were prokaryotic

stromatolites composed of layers of microbial biofilms

The first cells were most likely heterotrophic anaerobes because:

they utilized preformed organic molecules and did not need oxygen.

According to the serial endosymbiosis hypothesis, the ancestors of mitochondria are thought to be purple bacteria.

true

Autotroph

use inorganic compounds, such as CO2, to manufacture organic molecules

photosynthetic autotrophs

use light as an energy source cyanobateria

Fragmentation

walls develop within the cell, which then separates into several new cells

Protist classification

•Molecular analysis of the gene for small subunit ribosomal RNA, and other nuclear genes •Ultrastructure data revealed by electron microscopy

If a population of 2000 individuals has 120 aa genotypes, what would the genotype frequency of aa be?

0.06

the phylogenetic species concept

A definition of species as the smallest group of individuals that share a common ancestor, forming one branch on the tree of life. Shared derived characters

Protists

An informal group of primarily aquatic eukaryotic organisms with diverse body forms, types of reproduction, modes of nutrition, and lifestyles

What type of conversion occurs when a bacterium carrying viral genes takes on new, atypical characteristics?

Lysogenic

reverse transciptase

transcribes an RNA template into DNA

Phylogenetic systematics produce branching diagrams called:

cladograms.

Vertical gene transfer

transfers genetic material from parent to offspring

Gene Transfer Takes place by three different mechanisms:

transformation, transduction, conjugation

Currently, protists and other eukaryotes are split into five informal supergroups

Excavates, chromalvaeolates, rhizarians, archaeplastids, unikots

Ancestors of ____ may have possessed mitochondria, which were lost or reduced during evolutionary history.

Giardia

Prokaryotes:

Include two domains: Archaea and Bacteria

What is the outcome of the process of conjugation between two Paramecium cells?

Two new genetically identical cells that differ genetically from what they were before

Gram-positive bacteria

absorb and retain crystal violet stain

A cell wall

around the plasma membrane supports bacterium and keeps the cell from bursting under hypotonic conditions Includes peptidoglycan

Gregor Mendel

basic patterns of inheritance

The distinctive mating signals that have evolved as part of an animal's courtship illustrate what type of reproductive isolating mechanism?

behavioral isolation

Leonardo da Vinci

correctly interpreted fossils as the remains of once existing animals that had become extinct

Robert Koch

demonstrated that bacteria cause infectious disease

assortative mating

example of nonrandom mating in which individuals select mates by their phenotypes

p2

frequency of AA

What are the two major forces contributing to allopatric speciation?

genetic drift and natural selection

Subviral agents

infective agents that are smaller and simpler than viruses

inbreeding

mating of individuals who are more closely related than of they had been chosen at random from the population

linnaeus founded

modern taxonomy- the science of naming, describing, and classifying organisms

What is the only source of all new alleles in a closed population?

mutation

Neutral variation

not all mutations have an effect in the offsrping

Obligate anaerobes

only carry out anaerobic respiration

Heterophs

organisms that cannot make their own food and must feed on other organisms

A taxon that diverges earlier than the other taxa being considered in cladistic analysis is a(n):

outgroup.

species

second part of scientific name

synapomorphy

shared derived character shared by two or more groups and originated in their last common ancestor

A monophyletic group is defined by:

shared derived characters

plasmids

small circular fragments of DNA that may contain genes for catabolic enzymes, genetic exchange, or antibiotic resistance

mechanical isolation

structural differences in reproductive organs prevent successful mating between species

satellites

subviral agents that depend on co-infection of a host cell with a helper virus

outgroup

taxon considered top have branched off earlier than the taxa under investigation allows identification of changes

One group of fruit flies reproduces in August and one group reproduces in September. Which of the following mechanisms is preventing them from cross breeding?

temporal isolation

prezygotic barriers

temporal, habitat, behavioral, mechanical, gametic

gene flow generally increases variation within a population

the migration of breeding individuals between populations with a corresponding movement of alleles increasing genetic variability in the recipient population

population genetics

the study of genetic variability within a population and of the evolutionary forces that act on it

horizontal gene transfer

transfer of genes between species of the same generation

Horizontal gene transfer

transfers genetic material to another organism that is not its offspring

p= frequency of dominant allele

A

p+q =

1

thermophiles

which require very high or very low temperature for growth

classification

The process of grouping things based on their similarities

maximum likelihood

A principle that states that when considering multiple phylogenetic hypotheses, one should take into account the one that reflects the most likely sequence of evolutionary events, given certain rules about how DNA changes over time. STATISTICAL

Ciliates

Complex unicellular alveolates with a pellicle that gives them a definite but changeable shape •Hairlike cilia coordinate movement in motile forms, or draw in food in sessile forms •Two kinds of nuclei: diploid micronuclei function in reproduction; polyploid macronucleus controls growth and metabolism •Reproduce sexually by conjugation •Example: Paramecium

Trypanosomes

Excavate with a single mitochondrion that has an organized deposit of DNA (kinetoplastid) •Colorless•Many are parasitic and cause disease, often live in blood •Example: Trypanosoma brucei, a human parasite that causes African sleeping sickness transmitted by the bite of infected tsetse flies

limits on population growth

Organisms compete for limited resources; not all survive to reproduce

homologous structures

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

Which statement describes a temperate virus?

A temperate virus does not always destroy its host.

modern synthesis

A comprehensive theory of evolution that incorporates genetics and includes most of Darwin's ideas, focusing on populations as the fundamental units of evolution.

shared derived characters

An evolutionary novelty that is unique to a particular clade. = synapomorphy

adaptive radiation

An evolutionary pattern in which many species evolve from a single ancestral species

Endospores

Dormant, extremely durable cells

Antibiotic Resistance

Drug resistance may result from accumulation of mutations in plasmid or chromosomal DNA Overuse of antibiotics is the main cause of drug resistance

Chemoheterotrophs

Energy and carbon from other organisms •Includes decomposers that obtain carbon and energy from dead organic matter •The majority of bacteria are chemoheterotrophs

Chemoautotrophs

Energy from oxidation of inorganic chemical substances such as ammonia (NH3) and hydrogen sulfide (H2S). •Most archaea and some bacteria are chemoautotrophs •Carbon from inorganic compounds

Photoheterotrophs (purple nonsulfur bacteria)

Energy from sunlight •Carbon from other organisms

Photoautotrophs (cyanobacteria)

Energy from sunlight •Carbon from inorganic compounds

restriction enzymes

Enzyme that cuts DNA at a specific sequence of nucleotides

Protists are members of domain

Eukarya

Euglenoids

Most are unicellular flagellates •Some photosynthetic (autotrophic). Chloroplasts acquired by secondary endosymbiosis (three membranes!) •Some heterotrophic species absorb organic compounds by phagocytosis and digest prey in food vacuoles

Which statement about viruses is FALSE?

Viruses can manufacture proteins.

Which characteristic defines a virus?

Viruses cannot metabolize.

Spirals:

spirochete (flexible) or spirillum (rigid)• A comma-shaped spirillum is a vibrio

Phylogeny

the pattern or relatedness among evolutionary units such as individuals, genes, populations. or species

Pleisomorphies

"primitive" ancestral characters

In a certain population, the allele causing sickle cell anemia has an allele frequency of 0.3. If the population is in genetic equilibrium for this locus, what fraction of the population would be carriers for the allele (heterozygous individuals)?

0.42

four requirements of chemical evolution

1. little or no free oxygen: oxygen oxidizes the organic molecules necessary for life 2. a source of energy: lightning; cosmic and UV radiation 3. availability of chemical building blocks: water; dissolved inorganic minerals; gases in the early atmosphere 4. time: earth is approximately 4.6 billion years old

unikont

A eukaryotic cell with a single flagellum; thought to be the ancestor of all animals

bikont

A eukaryotic cell with two flagella; thought to be the ancestor of all plants

Transduction

A phage carries bacterial genes from one bacterial cell into another •Chromosome of new host becomes recombination of its own DNA and DNA from another bacterium

Whose findings of evolution by natural selection were presented with those of Darwin?

Alfred Wallace

the metabolism first hypothesis

An explanation of the origin of life, in which life began as a self-sustaining, organized system consisting of chemical reactions between simple molecules enclosed within a boundary

Parabasilids

Anaerobic, flagellated excavates that live in animals •Examples: Trichonymphs and trichomonads •Trichonymphs have hundreds of flagella and live in the guts of termites and wood-eating cockroaches - endosymbiotic bacteria digest cellulose in the wood •A trichomonad, Trichomonas vaginalis, causes trichomoniasis, a sexually transmitted disease in humans

At what stage of a lytic infection are phage components put together to make new viruses?

Assembly

Fimbriae and Pili

Bacteria use fimbriae and pili to attach to cell surfaces or to each other

Euglenoids and Trypanosomes

Euglenoids and trypanosomes have an unusual flagellum with a crystalline rod in addition to the 9+2 flagellum characteristic of eukaryotes •Have atypical mitochondria

Eukaryotic

Eukaryotic cells have nuclei and other membrane-enclosed organelles such as mitochondria and plastids, 9 + 2 flagella, and multiple chromosomes •Sexual reproduction, meiosis, and mitosis are also characteristic of eukaryotes

A characteristic that is independently acquired by reversal or convergent evolution exhibits homology.

False

Apicomplexans

Group of parasitic, spore-forming alveolates, some of which cause serious diseases in humans•Lack specific structures for locomotion and move by flexing •Have an apical complex of microtubules that attaches the parasite to its host •Produce sporozoites transmitted to next host •Example:•Plasmodium falciparum, which causes malaria •Toxoplasma gondii, which causes toxoplasmosis

What is a prophage?

It is phage DNA that is integrated into bacterial DNA.

Dinoflagellates

Marine plankton that are generally unicellular; a few are colonial•Alveoli contain interlocking cellulose plates with silicates; typically have two flagella; many are bioluminescent•Species may be photosynthetic, heterotrophic, or endosymbionts

What are the viruses that attack bacteria?

Phages

Retroviruses

RNA viruses that have a DNA polymerase (reverse transcriptase)

Stramenopiles: Water Molds

Stramenopiles once classified as fungi•Have a mycelium with coenocytic hyphae that digests organic material•Body consists of a single multinucleate cell•Asexual reproduction: zoosporangium develops into a new mycelium-> biflagellate zoospore•Sexual reproduction: fusion of male and female nuclei; produces thick-walled oospores

Dolphins share synapomorphies with mammals.

True

Prions induce normal Prp on the surface of brain cells to misfold and cause brain damage.

True

Budding

a cell develops a bulge (bud) that enlarges, matures, and eventually separates from the mother cell

homoplasy

a characteristic that appears homologous but is acquired by convergent evolution or reversal

Methanogens

a diverse group that inhabit oxygen-free environments

After a fire, a population of ants was reduced from 1 million to 1000. What type of genetic drift will occur in the gene pool of this population when it expands again?

a genetic bottleneck

The term clade most closely refers to:

a group of organisms that share common characteristics inherited from a common ancestor.

species

a group of similar organisms that are capable of interbreeding with one another

bottlenecks

a population may rapidly and severely decrease due to disease, exploitation, or sudden environmental change

secondary endosymbiosis

a process in eukaryotic evolution in which a heterotrophic eukaryotic cell engulfed a photosynthetic eukaryotic cell which survived in a symbiotic relationship inside the heterotrophic cell

viroid

a very small infectious piece of RNA responsible for some serious diseases in plants

lysogenic cycle

a viral reproductive cycle in which the viral DNA is added to the host cell's DNA and is copied along with the host cell's DNA

In the accompanying figure, note the variation in these closely related birds. What does this illustrate?

adaptive radiation

Fimbriae

are hundreds of hairlike appendages (shorter than flagella) made of protein

At what stage of a lytic infection are phage components put together to make new viruses?

assembly

Rod-shaped:

bacilli (bacillus) Occur as single rods or long chains of rods

microevolution

changes in allele frequencies that occur within populations

microevolution

changes within the populations over a few generations

paraphyletic group

contains a common ancestor and some, but not all, of its descendants

allopolyploidy

contains multiple sets of chromosomes from two or more species

Apomorphy

derived character

speciation

evolution of a new species

disruptive selection

extreme changes in the environment may favor two or more different phenotypes selects against the average phenotypes occurs only if alleles favored under the new circumstances are already present in the population results in a divergence of distinct groups of individuals within a population increases variation in the population

When the reproductive cells of different species are incompatible and cannot accomplish fertilization, it is referred to as:

gametic isolation.

reproductive isolation

gene flow between two species may be prevented by prezygotic or postzygotic barriers

temporal isolation

genetic exchange is prevented because two groups reproduce at different times of the day, season or year

The evolutionary species concept states that for a population to be declared a separate species, it must:

have diverged significantly from other populations.

polyploidy

having more than 2 sets of chromosomes reproductive isolation occurs in a single generation

If individuals in the same town continue to only mate with other individuals from the same town, one would expect to see an increase in ____ within the population.

homozygosity

Archaea have no peptidoglycan

in cell walls or simple RNA polymerase

Overproduction

in every generation each species has the capacity to produce more offspring than can survive

monophyletic group

includes ancestor and all descendants shared derived characters and sister taxa

Aerobes appeared after oxygen

increased in the atmosphere

virus

infective agent consisting of a core or nucleic acid and is dependent on a living host

peripatric speciation

is the divergence of a small population from a widely distributed ancestral form

viruses are considered a obilgate intracellular parasite

must depend on a living host to survive and replicate

Which process provides the genetic variability that natural selection acts on during evolution?

mutation

neutral variation

not all mutations have an effect on the offspring

Evolution occurs in populations

not individuals

Heterotrophs

obtain carbon atoms from organic compounds made by other organisms

Chemotrophs

obtain energy from chemical compounds

The traditional class Reptilia is ____ because it does not include all descendants of the most recent common ancestor of reptiles.

paraphyletic

principle of parsimony

parsimony requires the cladogram with the fewest changes in characters to be accepted as most probable

Darwin

proposed that all species currently living on our planet arose from earlier ones by a process of gradual evolution HMS Beagle

rna world model

proposed that the earliest life forms were mostly RNA

capsid

protein coat surrounding a virus- determine a shape

antigenic drift

seasonal evolution caused by natural selecting altering the structure of surface proteins

negative assortative mating

selection of mates with opposite phenotypes

positive assortative mating

selection of mates with the same phenotype

stabilizing selection

selects against phenotypic extremes, favors individuals with average phenotypes narrows the bell curve reduces variation

Because whales breathe via lungs, have a little hair when born, and nurse their young, these ____ characters allow us to classify them as mammals.

shared derived

the biological species concept

species are groups of interbreeding populations which are reproductively isolated from other such groups not based on attributes of the individual rather delinates species by properties possessed by populations

Thomas Malthus

suggested that limited food supply slows population growth

Jean Baptiste de Lamarck (1744-1829)

suggested that organisms pass traits they acquired during their lifetimes to their offspring

seriel endosymbiosis

suggests that early eukaryotic cells were assemblages of formerly free living prokaryotes chloroplast may have evolved from cyanobacteria that lived inside larger heterotrophic cells mitochondria may have evolved from aerobic bacteria inside larger anaerobic cells

The scientific study of the diversity of organisms and the evolutionary relationships between them is referred to as:

systematics

The scientific study of the diversity of organisms and the evolutionary relationships between them is referred to as:

systematics.

Peptidoglycan is absent in

the archaean cell wall

systematics

the study of relationships postulated to exist among species or higher taxa

chi squared test

to see of observed and expected frequencies are very close

microspheres

type of protobiont formed by adding water to abiotically formed polypeptides

Frequencies of alleles and genotypes in a population do not change from generation to generation

unless influenced by outside factors

directional selection

when an environment changes, phenotypes at one extreme of the normal distribution are favored occurs only if alleles favored under the new circumstances are already present in the population no effect on the amount of genetic variation in a population

outcomes of allopolyploids

• Selective pressures cause one of three outcomes in a new population of allopolyploids: 1. The new species may not compete successfully against established species, and becomes EXTINCT. 2. The new species may assume a new role in the environment and COEXIST with both parental species. 3. If it has greater fitness than one or both parental species, the new species may REPLACE the parent(s).

How Did Eukaryotes Evolve?

•Mitochondria and chloroplasts probably originated from endosymbionts: •Serial endosymbiosis hypothesis assumes certain organelles arose from symbiotic relationships between larger cells and smaller bacteria incorporated to live within them •Mitochondria may have originated as aerobic bacteria and chloroplasts may have originated as a cyanobacterium within a host cell

Diversity in the Protists

•Most are unicellular •Some form colonies •Some are coenocytic (multinucleate mass of cytoplasm) •Some are multicellular

Major Groups of Bacteria

•Proteobacteria (gram-negative) •Cyanobacteria (gram-negative) •Chlamydias (gram-negative) •Spirochetes (gram-negative) •Gram-positive bacteria

lytic reproductive cycle

(Virus)many copies of the phage are made within the bacterial cell and then the bacterium lyses, or breaks open. (the common cold)

Refer to the accompanying table. What is the allele frequency of allele D? Genotype Number DD 200 Dd 700 dd 100

0.55

If a population of 1000 individuals has 120 aa genotypes, 460 Aa genotypes, and 420 AA genotypes, what is the allele frequency of the dominant allele (A)?

0.65

Koch's Postulates

1.The pathogen must be present in every individual with the disease 2.A sample of the microorganism taken from the diseased host can be grown in pure culture 3.A sample of the pure culture causes the same disease when injected into a healthy host 4.The microorganism can be recovered from the experimentally infected host

The allele freqs. of the M and N blood group alleles are 0.6 and 0.4. How many of a population of 500 would be expected to have MN blood type if the population is in HW equilibrium

240

symplesiomorphy

A character shared by a number of groups, but inherited from ancestors older than the last common ancestor

shared ancestral character

A character, shared by members of a particular clade, that originated in an ancestor that is not a member of that clade.

phylogenetic tree

A graphic representation of lines of descent among organisms or their genes.

Which statement describes a virulent phage?

A virulent phage destroys bacteria.

Who is responsible for the first concept regarding the passing on traits or characteristics that were acquired during the lifetime of an organism to its offspring?

Jean Baptiste de Lamarck

Capsules and Slime Layers

Many prokaryote species produce a capsule or slime layer of polysaccharide or protein that surrounds the cell wall

taxonomy

The science of classifying organisms

For the relative proportions of alleles and genotypes in successive generations to stay the same, which condition must be met for the population?

There can be no natural selection.

How many domains form the three main branches of the tree of life?

Three

Three of the following ideas are consistent with Darwinian evolution. Which one is the exception?

Traits acquired during an individual's life are passed on to its offspring.

Golden Algae

Unicellular biflagellates•Freshwater or marine; contain chloroplasts•Primarily asexual reproduction (zoospores)•Make up a significant portion of marine nanoplankton•Important role as producers in marine environment•Classification is controversial•Some biologists group golden algae with diatoms; some with brown algae; some divide them into two phyla•Example: coccolithophorids ("scales" of silica or calcium carbonate)

Carl Woese

two groups - prokaryotes and eukaryotes

cladogram

type of phylogenetic tree in which each branch represents a clade, a group of organisms with a common ancestor

Most protists are ____, with each cell forming a complete organism capable of performing all the functions characteristic of life.

unicellular

mutation

unpredictable change in DNA the source of genetic variation in a population only mutations in reproductive cells are inherited

Facultative anaerobes

use oxygen for cellular respiration if available, but use anaerobic respiration when necessary

neutral variation

variation that does not alter the ability of an individual to survive and reproduce and is, therefore, not adaptive

viruses are not classified in any of the three domains

viruses classified based on host range and size shape etc

regressive hypothesis

viruses may have evolved from small independent cells that were parasites in larger cells and unneeded genes were gradually lost through evolution

pathogens

viruses responsible for serious diseases such as rabies, influenza, and AIDS