IB biology super review for paper 1 + 2

formula for chi-squared test

(the sum of) ((O-E)^2)/E O = observed (what did you gather) E = expected (what was expected)

Evidence for evolution provided by the fossil record

-A fossil is the preserved remains or trace of an organism from the remote past (totality of fossils = fossil records) -The fossil record shows that changes have occurred in organisms over time (evolution) -The law of fossil succession show that certain organisms appear in the fossil record in a consistent order (indicates an evolutionary sequence of development from ancestral forms) -Transitional fossils represent intermediary forms within the evolution of a genus (ex: archaeopteryx)

small intestine

-A long, highly folded tube where usable food substances (nutrients) are absorbed -Consists of three sections: duodenum, jejunum, and ileum

Role of mutagens and oncogenes in development of cancer

-A mutagen is an agent that causes a change in the genetic material of an organism -Chemicals in ciggs may cause cancer as an example -An oncogene is a gene that has the potential to cause cancer -proto-oncogenes code for proteins that promote cell growth and proliferation -tumor suppressor gene code for protein that repress cell cycle progression

relationship between solutes and solvents in a solution

-A solute is a substance that is dissolved in a solvent -Due to its polarity, water is often termed the 'universal solvent' (won't dissolve non-polar molecules)

depolarization

-A sudden change in membrane potential--usually from a (relatively) negative to positive internal charge -involves Na+ opening

How is ATP acting as the energy currency for cells

-ATP is composed of a sugar and a base (adenosine) connected to three phosphate groups -When a phosphate is cleaved (to form ADP + Pi) the energy stored in the bond is released

Two main factors that determine the impact of greenhouse gases

-Ability to absorb long-wave radiation -Concentration within the atmosphere (determined by rate of release and persistence)

process of the kreb cycle

-Acetyl CoA combines with a 4C compound (oxaloacetate) -The resulting 6C compound (citrate) is then broken back down into the original 4C compound (oxaloacetate) -This series of reactions involves decarboxylation (CO2 is released) and oxidation (large amounts of hydrogen carriers are produced) -These reactions also produce one molecule of ATP per cycle

process of muscle contraction

-Action potential in a motor neuron triggers the release of Ca2+ ions from the sarcoplasmic reticulum -Calcium molecules bind to troponin (on actin) and cause tropomyosin to move, exposing binding sites for myosin heads -The actin filaments and myosin heads form a cross-bridge that is broken by ATP -ATP hydrolysis causes the myosin heads to swivel and change orientation -Swiveled myosin heads bind to actin filament before returning to their original conformation (releasing ADP) -Repositioning of the myosin heads move the actin filaments towards the center of the sarcomere -The sliding of actin along myosin therefore shortens the sarcomere, causing muscle contractions

Significance of adhesion and cohesion for water

-Adhesive properties result in capillary action when in contact with charged or polar surfaces -Significant because it allows for transpiration stream in plants (flow of water against gravity) -Cohesive results in water having higher surface tension because of extensive H bonding -Significant as it allows for small insects to move along surface of water

cell differentiation through selective gene expression

-All cells of an organism contain an identical genome -They differentiate through the expression of some genes and not others in the genome -Activation of certain genes by chemicals signals will cause a cell to develop differently from other cells -Differentiation causes different cell types to become more specialized and distinct as the mature

cell theory

-All living things are composed of cells -cells come from preexisting cells -Cells are smallest unit of life

Describe the basic structure of a generalized amino acid

-Amine group on the left -Variable (R) group on the bottom -Carboxyl group on the right -hydrogen on top -Carbon in the middle

Outline structural organization of a polypeptide chain (monomer -> polymer)

-Amino acids are joined via condensation reactions to form dipeptides (a water molecule is produced) -The covalent bond that connects amino acids together in a polypeptide chain is called a peptide bond -Polypeptide synthesis occurs at the ribosome via the process of translation

production of monoclonal antibodies

-An animal (ex: mouse) is injected with antigen to produce specific plasma cells -Plasma cells are removed and fused with tumor cells capable of endless divisions -The resulting hybridoma will synthesize large quantities of the specific antibody (monoclonal)

why are antibiotics effective against bacteria but not viruses

-Antibiotics are compounds that inhibit or kill bacteria by targeting the structures or metabolic pathways of prokaryotes (not eukaryotes) -Viruses don't have metabolism and are therefore not affected1

Compare apoptosis and necrosis

-Apoptosis: programmed cell death (cell suicide). Involves cellular signals and mitochondrial proteins. Membrane bulges and contents are then repackaged for recycling to other cells. -Necrosis: Uncontrolled cell death (ie homicide). Premature death of cell due to injury of trauma. Membrane destabilizes, leading to cell lysis. Released cell contents trigger inflammation.

Role of pili

-Attachment pili allow bacteria to adhere to surfaces -Sex pili ( ͡° ͜ʖ ͡°) allow bacteria to exchange genetic information (plasmids) via bacterial conjugation

how is huntington's disease linked to inheritance

-Autosomal dominant disease -Caused by a mutation to the HTT gene on chromosome 4 -Abnormal production of the Huntingtin protein leads to neurodegeneration and dementia

how is cystic fibrosis linked to inheritance

-Autosomal recessive disease -Caused by a mutation to the CFTR gene on chromosome 7 -Causes the production of sticky mucus leading to obstructed airways and digestive issues

How are auxin concentration gradients established within plant tissues

-Auxin efflux pumps set up concentration gradients of auxin in response to stimuli -These pumps control growth direction by determining areas with high auxin levels

Role of auxin in apical dominance

-Auxin released by the apical meristem in shoots promotes apical growth -It additionally inhibits growth in lateral buds (a condition called apical dominance) -As shoots grow further from lateral buds, inhibition is diminished, allowing spread Grows up, then out

explain bacterial cell division

-Bacterial cells divide by binary fissions (asexual reproduction) -The circular DNA molecule is copied and then is anchored to the plasma membrane -The DNA loops are drawn apart as the cell elongates, before dividing (cytokinesis) to form two clones

why is the ventilation system needed to maintain a concentration gradient within the alveoli

-Because gas exchange is a passive process, a ventilations system is needed to maintain a concentration gradient -the lungs continually cycle fresh air into the alveoli from the atmosphere -the lungs also have a very large surface area, so as to increase the overall rate of gas exchange

significance of the thermal properties of water

-Because water has a high specific heat capacity, it functions as an excellent biological coolant -Sweating results in evaporative cooling, as ambient heat is absorbed to evaporate water (breaks H bonds) -This cools the air surrounding the skin and directly draws heat from the skin

distinguish between primary and secondary tumors

-Benign tumors that remains in its original location is called a primary tumor -A tumor that spreads is a secondary tumor

outline evidence that can falsify the Davison-Danielli and Nicolson-Singer models

-Biochem. evidence: Not all membranes consist of a constant ratio of lipid:protein (precludes 'sandwich' model), and membrane protein vary in size and are insoluble to water (can't form outer layer) -Anti-body tagging: Membrane proteins are mobile and not fixed in place (do not form a static layer) -Freezing Fracturing: fracturing the membrane reveals a rough and irregular internal surface, which are interpreted as transmembrane proteins

How does Independent Assortment give rise to infinite genetic variety

-Bivalents will line up at the cell's equator in a random orientation during Metaphase I -Means there is an equal probability of a gamete containing the maternal OR paternal copy for any chromosome pair -Because human cells have 23 chromosome pairs, there are 2^23 possible chromosomes (23 because there are 23 possible chromosome pairs that can have changes, the formula is 2^n, where n is the amount of chromosomes) (this equates to over 8 million different gamete combinations)

causes and consequences of clotting in the coronary arteries

-Blood clots form in the coronary arteries when the vessels are damaged by cholesterol build-up (antherosclerosis) -The restricted blood flow increases pressure in the artery, leading to damage to the arterial wall (plaques) -If the plaque ruptures, blood clotting is triggered, forming a thrombus that restricts blood flow -clot formation in coronary arteries leads to coronary thrombosis and heart attacks

role of insulin and glucagon in the regulation of blood sugar levels

-Blood glucose levels are regulated by pancreatic hormones insulin (from Beta cells) and glucagon) (from a cell) -Insulin lowers blood sugar levels by stimulating glycogen synthesis and increasing rate of glucose breakdown -glucagon raises blood sugar levels by stimulating glycogen breakdown and decreasing glucose breakdown

pressure changes in the heart during the cardiac cycle

-Blood returning to the heart will flow into the atria and ventricles as the pressure in them is lowered -as ventricles fill, atria contract (atrial systole), increasing pressure in atria and forcing blood into ventricles -as ventricles contract, ventricular pressure exceeds atrial pressure and AV vales close to prevent back flow -When ventricular pressure exceeds pressure in aorta, the aortic valve opens to release blood into the aorta -as blood exists the ventricle, ventricular pressure falls below aortic pressure, so the aortic valve closes -When ventricular pressure drops below atrial pressure, the AV valve opens and cycle begins again

How does Boyle's Law relate to the mechanism of breathing

-Boyle's Law: pressure is inversely proportional to volume (ie more volume = less pressure) -Breathing utilizes antagonistic sets of reparatory muscles to facilitate the passage of air -The muscles change lung volume to create a negative pressure vacuum -when pressure in the lung is less than atmospheric pressure, air flows in to equalize (and vice versa)

Evidence from Pasteur's experiment that demonstrates that abiogenesis no longer occurs

-Broths stored in vessels with long tubings (swan neck ducts) that can prevent passage of dust particles -The broths were boiled to kill any micro-organism present in the growth medium (sterilization) -Growth only occurred in the broth if the flask was broke open, exposing the contents to contamination -From this it was concluded that bacterial growth came from contaminants and did not spontaneously occur

four methods of natural cloning

-Budding (ex: yeast) -Binary fission (hydra) -Fragmentation (starfish) -Parthenogenesis (some fish species)

Effects of different factors on the rate of photosynthesis: CO2 concentration

-CO2 is fixed (via enzyme) to form organic compounds -Activity increases at higher concentrations as there are more frequent collisions -above a certain level activity will plateau as all enzyme active sites are occupies

Changes in atmospheric CO2 levels detected at the Mauna Loa observatory

-CO2 levels fluctuate annually (lower in summer because of higher photosynthesis rates) -CO2 levels are steadily increasing (because of increased burning of fossil fuels) -Global trends conform to northern hemisphere (because of more people and land mass) -CO2 levels are now the highest ever recorded

How did Calvin establish the stages of the Calvin cycle via the 'lollipop' experiment

-Calvin treated algae with radioactive carbon (14C) in a 'lollipop' apparatus -Algae was then subjected to light to promote photosynthesis -Algae was then killed (with alcohol) at different time periods and the carbon compounds were then extracted (via 2D chromatography) and then visualized (via autoradiography) -This allowed Calvin to elucidate the order in which carbon compounds occurred (i.e. RuBP to GP to TP to RuBP)

Two properties of RNA that allows it to play a role in life

-Can self-replicate (although DNA supersedes it because double strands increase stability) -Can act as a catalyst (although proteins supersedes it because of greater variability of subunits)

Causes of lung cancer

-Cancer is the uncontrolled proliferation of cells, leading to abnormal growth (tumors) -factors that can contribute to the development of lung cancer include genetics, age, some diseases, smoking asbestos, and radiation

three ways water transport can be modelled in xylem

-Capillary tubing -porous pots -Filter paper

key events in the light-independent cycle (Calvin cycle)

-Carbon fixation: RuBP is carboxylated by CO2 to form two 3C compounds (GP) -Reduction: GP is reduced by NADPH and reacts with ATP triose phosphate (TP) -Regeneration: One TP molecule is used to make organic compounds, the rest are reacted with ATP to form RuBP

How does the structure of carbon atoms contribute to the formation of organic life

-Carbon forms the base of organic life because of its capacity to form large molecules -Carbon has four valence electrons and can form 4 covalent bond -allows for it to be a stable backbone in a large variety of compounds

benefits and risks with amniocentesis

-Cells are extracted from the amniotic fluid -Occurs later in the pregnancy (~15 weeks) but has a slightly lower risk of miscarriage (~.5%)

Benefits and risks of chorionic Villi sampling

-Cells are extracted from the placenta (chorionic villus) -Occurs earlier in the pregnancy (~11 weeks) but has a slightly higher risk of miscarriage (1%)

The method which cells are obtained for karyotyping

-Cells are isolated and treated with drugs to promote cell division (makes chromosomes visible to microscopes) -Cells are arrested during mitosis and then chromosomes are isolated and visualized

Adaptations cells can make to maximize SA:Vol

-Cells may adopt elongated or flattened shapes -Cells may possess cellular extensions (ex: root hairs) or fold to plasma membrane -cells may reduce volume by including larger central vacuoles, as plant cells do

How are cells organized in multicellular organisms?

-Cells of the same type may group together to form tissue -different tissues interact to form organs -organs combine to form organ systems

How did John Cairns elucidate the length of chromosomes via autoradiography

-Cells were grown in a solution including radioactive thymidine (tritated thymidine) -The radioactive thymidine was incorporated into the DNA of the cell (T present in DNA but NOT found in RNA) -The chromosomes were then isolated and fixed to a photographic surface -This surface was immersed in a solution of silver bromide (which turns into metal grain if exposed to radiation) -The silver grains appear only where the DNA was present, allowing chromosome length to be determined

how do ventilation rates change with exercise

-Cellular respiration produces CO2 as a waste product -rising levels of CO2 in the bloodstream alters the blood pH (lower) -This triggers an increase in ventilation rates

Ethical issues with IVF: for

-Chance for infertile couples to have children -screening of embryos could decrease suffering from genetic disease -Spare embryos can be stored for future pregnancies or used for research

light-dependent reaction

-Chlorophyll absorbs light, which triggers the production of ATP -Light is also responsible for the photolysis of water, which produces hydrogen (carried by NADPH) -The photolysis of water also produces O2 gas as a by-product

identify the function of chloroplast and identify where it is in the plant tissue

-Chloroplast are the organelle responsible for photosynthesis -chloroplast are found in photosynthetic tissues -chloroplast are NOT found in all plant tissues (ex: root cells)

Label a cell membrane

-Cholesterol: the little hexagon things in the membrane -Integral protein: they're transmembrane -Peripheral protein: NOT transmembrane--looks like a clothes hanger -Glycoprotein (receptor molecule): on the outside of the cell and has a little tail Phospholipid bilayer: The lipids that make up the membrane

Importance of chromosome number to the reproduction of a species

-Chromosome number is a characteristic feature of a species -organisms with different haploid numbers will generally be unable to produce viable diploid zygotes (hybrid species are infertile)

Homologous chromosomes

-Chromosome pairs that share the same structural features and have the same genes at the loci position -They represent the maternal and paternal copies of a chromosome

Prophase I

-Chromosomes condense, nuclear membrane dissolves -Homologous chromosomes form bivalents -Crossing over occurs

Effects of different types of fatty acids on lipoprotein levels

-Cis fats raise levels of HDL (lowers blood cholesterol) -Saturated fats raise levels of LDL (raise blood cholesterol) -Trans fats raise levels of LDL and lower levels of HDL (significantly raise blood cholesterol) -Cis fats are generally considered good for health, saturated and trans are considered bad

how do competitive inhibiters affect enzyme activity

-Competitive inhibitors are similar in structure and chemical properties to the substrate -It can bind to the active site and block the substrate binding increasing substrate concentration will reduce the effect of a competitive inhibitor

Peristalsis

-Continuous segments of longitudinal smooth muscle rhythmically contracting and relaxing -Food is moved unidirectionally along the alimentary canal in a caudal direction (mouth to anus)

Segmentation

-Contraction and relaxation of non-adjacent segments of circular smooth muscle in intestines -contractions move chyme in both directions, allowing for a greater mixing of food with digestive juices

example of non-competitive inhibitor

-Cyanide binds to a carrier protein in the electron transport chain and causes a conformational change -The carrier can no longer shuttle electrons, so oxidative phosphorylation (aerobic respiration) is shut down -Without energy (ATP) the cells die, making cyanide a very potent poison

Role of cyclins in the control of the cell cycle

-Cyclins are a family of regulatory proteins that control progression of cell cycle -Cyclins bind to cyclin dependent kinases (CDKs) and form an activated complex -This complex phosphorylates proteins involved in specific cell cycle events -After the event has occurred, the cyclin is degraded and CDKs rendered inactive

how are genes packaged in eukaryotes?

-DNA in eukaryotes is packaged with proteins in the nucleus to form chromatin -Active genes are loosely packaged in an expanded and accessible form called euchromatin -inactive genes are usually tightly packaged in a more condensed form called heterochromatin -Packaging of chromatin varies between cells according to which genes are active and inactive

Prokaryotic chromosome structure

-DNA is circular -DNA is naked (not bounded to proteins) -Single chromosome (called the genophore) -found in the nucleoid region of the cytosol

Eukaryotic structure of a chromosome

-DNA is linear -DNA is bound to histone proteins -Chromosome may exist in pairs (diploid) -Found in the nucleus

list the changes in DNA organization during interphase and mitosis

-DNA is usually loosely packed within the nucleus as chromatin -During mitosis, the DNA supercoils and chromatin condenses to form visible chromosomes -Because DNA is replicated in the S phase, each chromosome is made of identical sister chromatids

what is the organization of DNA into chromatin within eukaryotic cells

-DNA is wrapped around histone proteins to form nucleosomes -Nucleosomes are grouped together (chromatosomes) and then arranged into fibers (chromatin) -DNA is usually organized as chromatin within the nucleus, except during cell division (when chromatin condenses to form chromosomes)

How are nucleotides linked together to form DNA strands

-DNA nucleotides are linked by covalent phosphodiester bonds (between the 5'-phosphate and 3'-hydroxyl of two nucleotides) to form long polynucleotide strands -Two strands join together via complementary base pairing (G pairs with C via 3 H bonds, a pairs with T via 2 H bonds) -The two strands run antiparallel to each other so the bases face each other and form hydrogen bonds -The double stranded DNA then twists into a double helix -Each twist occurs every ~10 nucleotides

Different events that occur during interphase

-DNA replication (S phase) -Organelle duplication -Cell growth -Transcription/Translation -Obtain nutrients -Respiration (cellular) Acronym: DOCTOR

difference between leading and lagging strands as they relate to okazaki fragments

-DNA strands are antiparallel, so DNA pol III moves in opposite direction on the two strands of DNA -On the leading strand, DNA pol III moves in the same direction as the helicase, so synthesis can continue -On the lagging strand, DNA pol III moves in the opposite direction to helicase, so synthesis is discontinuous -The fragments generated on the lagging strand are called Okazaki fragments

How did Franklin and Wilkins use X-ray crytallography to elucidate the structure of DNA

-DNA was crystallized and then targeted with an X-ray (whose beam became diffracted by DNA crystals) -The scattering pattern created by the diffracted x-ray was recorded on film -This pattern was then analyzed to elucidate the structure of DNA

Evolutionary changes of the beaks of Darwin's finches

-Darwin's finches demonstrate adaptive radiation and show marked variation in beak size and shape according to diet -Finches that feed on seeds possess compact, powerful beaks (large beaks are better equipped to crack seed cases) -In 1977, an extended drought resulted in plants producing larger seeds with tougher seed casings -Finches with larger beaks were better adapted and thus produced more offspring with larger beaks (evolution)

Role of oxygen in the electron transport chain

-De-energized electrons must be removed from the electron transport chain for it to continue to function (otherwise the chain would become blocked) -O2 is the final electron acceptor--it takes the electrons (along with the protons from the matrix) to form water (the removal of protons also helps to maintain the gradient needed for chemiosmosis)

Role of decomposers in maintaining nutrient supplies

-Decomposers release enzymes to externally break down organic materials -this allows for inorganic compounds to be replenished within the environment (ex: returned to the soil)

role of deoxynucleoside trophosphates (dNTPs) in the replication process

-Deoxynucleoside triphosphates align opposite their complementary base partner -DNA pol III cleaves two of the phosphates and uses energy to form a covalent phosphodiester bond -In this way, DNA pol III synthesizes a new DNA strand

how are dideoxynucleotides used in DNA sequencing

-Dideoxynucleotides (ddNTP's) lack the 3'-hydroxyl group needed to form a phosphodiester bond -this means the inclusion of the ddNTP will terminate the extension of a DNA sequence at that point -Four PCR cycles are set up, each with a differetn ddNTP (ddA, ddT, ddG, or ddC) and a stock of normal bases -Each time the ddNTP is incorporated the sequence stops, generating fragments -When these fragments are separated and then ordered according to their length, the DNA sequence is discerned -This process can be automated by using flourescently labelled ddNTPs that can be detected by machines

Different methods of biological classification: phylogenetic

-Differentiates organisms based on sequence similarities (genetics) -Organisms with a greater similarity in DNA or amino acid sequences are more closely related

How do DNA methylation patterns differ between identical twins and the significance of this

-Direct methylation of DNA also decreases gene expression (preventing binding of transcription factors) -Hence, genes that are methylated are not expressed, while genes that are not methylated are expressed -Because DNA methylation is influenced by environmental factors, identical twins develop different methylation patterns over time--this explains why twins may look different despite having identical genomes

difference between primary and secondary active transport

-Direct: ATP hydrolysis is used to mediate transport by causing a conformational change in the protein pump (translocate molecules against gradient) -Indirect: Transport is coupled to another molecule moving along an electrochemical gradient

term used to describe a disease that can cross species barriers and identify a specific example

-Disease from animals that can be transmitted to humans are called zoonotic diseases (or zoonoses) -Ex: rabies (dog), some strains of influenza (bird flu) and bubonic plague (fleas on rats)

Sympatric speciation

-Divergence of species within the same geographical location (no physical barrier) -reproductive isolation may be a result of genetic abnormalities (ex: chromosomal errors)

Crossing over

-During Prophase I, homologous pairs of chromosomes connect via chiasmata (between non-sister chromatids) in a process called synapsis--the resulting complex is called a bivalent -Chiasmata represent the point where genetic information has been exchanged (forming recombinants) -Recombination through gene exchange produces new combinations of alleles

process by which amino acids are attached to tRNA molecules

-Each tRNA molecule carries a specific amino acid (designated by the codon / anticodon) -Hence, different tRNA molecules associate with specific tRNA-activating enzymes -Enzyme binds ATP to an amino acid (forming a 'charged' amino acid-AMP complex) -the charged complex is then transferred to the tRNA acceptor stem (and AMP is released) -The purpose of 'charging' the molecule is to provide the energy needed in translation for peptide bond

How is electron tomography used to produce images of active mitochondria

-Electron tomography involves repeated imaging of a mitochondria with a transmission electron microscope -These cross-sections are taken at different angles along distinct planes -The images are then compiled by computer to generate 3D representations of the organelle

How are metabolic pathways controlled by end-product inhibition

-End-product inhibition (or feedback inhibition) is when a product of metabolic pathway inhibits one of the enzymes involved in its production -This allows reaction rates to be tightly regulated

role the environment can play in regulating transcription

-Environmental factors can trigger the production (or change in levels) or transcription factors -Example: hydrangea flowers change color according to the pH of the soil

Substrate concentration on Enzyme activity

-Enzyme activity increases as substrate concentration increases, as there are more substrate particles, leading to a higher rate of successful collisions. -At a certain point, the rate of enzyme activity will plateau, as all the active sites are occupied.

pH on enzyme activity

-Enzymes have an optimal pH at which the rate of reaction is highest. - At higher and lower pH levels, activity will decrease (leading to a bell curve). - This is because pH affects the charge and solubility of the enzyme. -The change in the enzyme's chemical properties causes it to denature.

role of ovaries in menstrual hormones

-Estrogen and progesterone promote development and thickening of the endometrium -They stimulate FSH/LH secretion in the follicular phase and inhibit FSH/LH secretion in the luteal phase

how does synaptic transfer enable complex decision making in the CNS

-Excitatory neurotransmitters will depolarize a post-synaptic neuron (more likely to fire), whereas inhibitory neurotransmitters will hyperpolarize a post-synaptic neuron (less likely to fire) -The sum of excitatory and inhibitory signals determines where the threshold for an action potential is reached -Hence, the composition of neurotransmitters released determines the differential pathways of nerve signals

role of anterior pituitary in menstrual hormones

-FSH acts on ovaries to stimulate follicular growth and stimulates estrogen secretion (from follicles) -LH acts on ovaries to trigger ovulation, which results in a corpus luteum that produces progesterone

Show a basic structure of a generalized dipeptide

-Far left: amino group -Carbon in the middle of the left amino acid -R group on bottom -Hydrogen on top of the carbon -Peptide bond formed from the condensation of the OH of the left-ward amino acid and the right-ward amino acid's Dihydrogen mononitroxide (forms a water molecule that leaves, forming the peptide bond) -Carbon group connects to that -Hydrogen group on top -R group on bottom -Carboxyl group on the far right -This produces a water molecule

role of negative feedback in homeostatic regulation

-Feedback mechanisms involve a change being detected by a receptor and a response initiated by an effector -In negative feedback, the effect is antagonistic (opposite) to the stimulus -This means the detected change is reversed

large intestine

-Final section of alimentary canal, where water and dissolved minerals are absorbed -Consists of the ascending/ transverse/ descending/ sigmoidal colon, as well as the rectum

Secondary protein structure

-Folding of a polypeptide chain into repeating arrangements (alpha helices or beta-pleated sheets) -Formed via hydrogen bonds between the amine and carboxyl groups of non-adjacent amino acids

Two potential applications of DNA profiling

-Forensic investigations -Paternity testing

process of fossilization

-Fossilization preserves hard body parts (although soft parts may leave trace remains--such as imprints) -Fossilization is a rare process that requires the preservation of remains (i.e. no scavenging), anoxic (lack of oxygen for decomposition) conditions, and high pressure (to turn hard body parts into fossilized minerals) -These conditions are most likely to occur on land as a result of rapid burial

Significance of complementary base pairing in conservation of base sequences

-Free nucleotides can only align opposite their complementary base partner (A - T, C - G) -This means a newly synthesized strand will be identical to the complementary partner of a template strand -Hence, the base sequence is conserved

Differentiate between the three gap phases

-G1: Cell growth and prepares for DNA replication (S phase) -G2: cell finishes growing and prepares for cell division (M phase) -G0: non-dividing, resting phase for fully differentiated cells (e.g. neurons)

Purpose and process of gel electrophoresis

-Gel electrophoresis separates fragments of DNA or protein based on size -DNA is run in an agarose gel (moves towards the positive terminus as phosphate is negative) -Proteins are run on a polyacrylamide gel after first being treated with SDS (homogenises protein charge)

process of gene transfer

-Gene of interest and plasmid vector are isolated from cells and amplified with PCR -Gene and plasmid are cut with restriction enzyme -DNA ligase fuses together gene and plasmid to form a recombinant construct -The construct is then inserted into a host cell (via any of a number of different techniques) -Transgenic cells are then selected by growing on antibiotic media (the plasmid has a resistance gene) -The transgenic cells are then grown in culture and the newly expressed protein can then be extracted -An example of this process is the mass reproduction of human insulin by transgenic bacteria

relationship between genes and polypeptides

-Genes are sequences of DNA that encode polypeptides -Typically, one gene equals one polypeptide--however, exceptions exist (ex: tRNA genes)

factors that influence genetic drift and two conditions by which this factor may occur

-Genetic drift is a change in composition of a gene pool because of random events; population size impacts it -Size affects stability of allele frequencies (high drift in small populations / low drift in large populations)

identify factors that contribute to the germination of a plant

-Germinating seeds require: -oxygen (for ATP via aerobic respiration) -water (to metabolically activate cells) -temp. (for optimal enzyme activity) -pH (suitable soil conditions for enzyme) -In addition, particular species may require specialized conditions, such as fire, freezing, washing, and digestion

Three climate conditions that greenhouse gases influence

-Global temps -Weather conditions (more frequent extreme conditions) -Ocean currents (changes can cause longer el niño events)

process if glycolysis

-Glucose is phosphorylated with 2 ATP (destabilizing the molecule) -Molecule is then split in two (lysis) to form two 3C compounds -These compounds are oxidized (NADH is formed) -Four ATP molecules are produced (for a net gain of TWO ATP) -the final product is two molecules of pyruvate (3C)

relationship between greenhouse gases and the greenhouse effect

-Greenhouse effect functions to trap heat within the atmosphere and prevent rapid temp. changes -incoming radiation (from the sun) is shorter wave radiation (ultraviolet radiation and visible spectrum) -the Earth's surface absorbs this radiation and reemits it at a longer wavelength (infrared radiation/heat) -Greenhouse gases absorb and re-radiate the longer wave radiation and hence retain heat in the atmosphere -The higher the concentration of greenhouse gases in the atmosphere, the more heat retained

Different methods of biological classification: natural

-Groups organisms based on similarities first and then identify shared characteristics -Shows how closely related organisms are and allows determination of evolutionary links

Role of stomata in regulating the level of evaporation from the leaf

-Guard cells that flank the stomata can regulate the transpiration ate -Guard cells occlude the opening when flaccid -Abscisic acid regulates guard cell turgor

Cis isomers

-H atom on the same side of the double bond -Double bond creates kink in fatty acid chain -Are loosely packed and usually liquid -Occurs commonly in nature -Generally considered good for health

Trans isomer

-H atoms on opposite sides of the double bond -Double bond does NOT create kink in the chain -Are tightly packed and usually solid -Occurs in process oods -Generally considered bad for health

William Harvery's findings on the circulation of blood

-Harvey disproved the prior theories of Galen by suggesting -The major blood vessels (arteries and veins) are part of a single connected blood network -Blood flow is unidirectional (because of valves) and continuous flows (it is not consumed by the body) -The heart is a central pump (blood carried from the heart by the arteries and to the heart and veins)

How did Morgan discover non-Mendelian ratios via experimentation with Drosophila

-He undertook breeding experiments with Drosophila (fruit flies) and found a clear sex ( ͡° ͜ʖ ͡°) bias in the inheritance of certain traits -Morgan determined that genes located on a shared chromosome would NOT independently assort (+ have non-Mendelian ratios)

List three ways in which energy may be lost from one trophic level to the next

-Heat -Converted into another form of energy -Stored chemical energy remains unconsumed

Helicase in DNA replication

-Helicase unwinds and separates double-stranded DNA molecules (by breaking the hydrogen bonds between the complementary base pairs -breaks hydrogen bonds between complementary base pairs

outline the methodology and conclusions of the Hershey-Chase experiment

-Hershey and Chase demonstrated that DNA was the genetic material by using radioactively-labeled viruses -Viruses were prepared with radioactive phosphorus (labeled DNA) or radioactive sulphur (labels protein) -Viruses then infected bacteria, before the bacteria and virus were separated via centrifugation (bacteria is heavier and forms a pellet, while the smaller virus remains in the supernatant) -When radioactive sulphur was used, radioactivity was detected in supernatant (not transferred to bacteria) -When radioactive phosphorus was used, radioactivity was detected in pellets (WAS transferred to bacteria)

Health implications of high levels of blood cholesterol

-High levels lead to hardening and narrowing of arteries -The cholesterol forms fat deposits in the arterial lining, leading to the development of plaques -If a plaque ruptures, blood clotting will cause the vessel to become blocked -If coronary arteries become blocked, coronary heart disease will result (resulting in heart attacks, etc)

Homologous chromosomes versus sister chromosomes

-Homologous chromosomes are the maternal and paternal copies of a given chromosome -Homologous chromosomes have the same structure and the same genes at the same loci position Sister chromatids are the duplicated copies of a chromosome's DNA (copied during S phase of interphase)

one strategy horticulturalists can use to promote flowering of short-day plants out of season

-Horticulturalists can manipulate flowering by controlling the exposure to light -Short-day plants can be induced to flower by covering with black cloth for ~12 hrs a day

describe chemiosmosis at the electron transport chain

-Hydrogen carriers (e.g. NADH) donate high energy electrons to the electron transport chain -As electrons move through the chain they lose energy, which is used to translocate protons to the intermembrane space--this creates an electrochemical gradient (or proton motive force) -The proton gradient will cause the hydrogen ions to diffuse back into the matrix (chemiosmosis)

hypertonic, hypotonic, and isotonic

-Hypertonic: higher solute concentration relatively, and water flows out of the cell -Hypotonic: low solute concentration, water flows into cell -Isotonic: equal solute concentration, no net movement of water

Ethical issues with IVF: against

-IVF is expensive (access issues) and success rate is low (stressful) -Could lead to eugenics -Often leads to multiple pregnancies (extra risks) -Issues concerning disposal of unused embryos (right to life concern) -Inherited forms of infertility may be passed on to children

benefits of immobilized enzymes in industry, with examples

-Immobilized enzymes have been fixed to a static surface to increase enzyme efficiency -Enzyme concentrations are conserved, as the enzyme is not dissolved--so it cannot be re-used -Product is easily separated from enzymes, as the enzymes are fixed in position -Examples include food production, medicine, and bio-fuel products

formation of fossil fuel: peat/coal

-In anaerobic conditions (ex: waterlogged soils), saprotrophs can only partially decompose organic matter -the remaining carbon-rich material stays within the soil and forms peat -When compressed under sediment, the high pressure and heat force out moisture and turn peat into coal

specific example of end-product inhibition

-In plants and bacteria, isoleucine can be synthesized from threonine -this multi-step reaction involves the enzyme threonine deaminase -Isoleucine can bind to an allosteric site on threonine deaminase and non-competitively inhibit it -Thus when isoleucine levels are high its production is reduced, but when levels are low, production proceeds

Role of negative feedback in the menstrual cycle

-In the follicular and luteal phase, estrogen / progesterone inhibits FSH / LH production -This is an example of this type of feedback as the response (estrogen production) is antagonistic to the stimulus (FSH/LH production

How do increasing concentrations of atmospheric CO2 threaten coral reefs

-Increased concentrations of dissolved CO2 lowers ocean pH (more carbonic acid = more acidity) -More hydrogen ions also means there are less free carbonate ions for calcification (shell formation) -Hence, an increase to water acidity correlates with significant thinning of calcium exoskeletons -Low pH conditions are also detrimental to polyp survival, leading tp coral bleaching

How do abiotic factors affect rate of transpiration in a typical terrestrial plant: temp

-Increasing ambient temp causes an increase to the rate of transpiration -Higher temp leads to an increase in the rate of evaporation within the mesophyll

Effects of different factors on the rate of photosynthesis: light intensity

-Increasing light levels result in more photoactivation of chlorophyll (= increased activity) -At a certain intensity, all chlorophyll are photoactivated and so activity plateaus

independent assortment

-Inheritance of one gene/trait is independent to the inheritance of other gene/trait -Alleles can divide randomly of each other (with each at an equal chance), leading to more genetic variation -As humans have a haploid number of 23, there are 2^23 gamete combination (over 8 million combinations) -For example, if there are 2 blue alleles and 2 red alleles, there is an equal chance that the two blue alleles and two red alleles separate together into Metaphase II as is possible the red and blue pairs split with each other upon getting to Metaphase II

process of clotting

-Injured cells and platelets release clotting factors -Factors convert prothrombin (inactive) into thrombin (active) -Thrombin converts fibrinogen (soluble) into fibrin *insoluble) -fibrin forms a mesh of insoluble fibers that trap blood cells -Clotting factors also cause platelets to become sticky and form a solid plug (clot)

Differentiate between integral and peripheral membrane protein

-Integral are permanently attached to membrane and are typically transmembrane (go through the bilayer) -Peripheral are temporary proteins attached by non-covalent interactions and associate with only one surface of he membrane

hw are the structures of the potassium channel helping diffusion in nerve cells

-Integral proteins with a hydrophilic inner pore via which potassium ions may be transported -inner pore contains a selectivity fire to restrict the passage of alternative ions -channels adopt an open/close conformation based on membrane polarity and binding of neurotransmitters

Meiosis II

-Involves separation of sister chromatids -Is a mitotic division (haploid to haploid) -Does not promote genetic variation

how are stem cells potentially artificially derived?

-Involves the creation of embryos via therapeutic cloning, excess embryo are created in this process, raising the ethical concerns about destruction of embryos. -Nuclear reprogramming: induce change in the gene expression profile of a cell to transform it

Meiosis I

-Involves the separation of homologous chromosomes (bivalent / tretrads) -Reduction division (diploid to haploid) -Promotes genetic variation (crossing over and random assortment)

How does the solubility of molecules affect their mode of transport within the blood

-Ionic compounds (ex: salt) dissociate in the water and are transported within blood plasma in a dissolved state -Glucose and other monosaccharides are water soluble and hence are transported freely within blood plasma -Amino acids are zwitterions and can freely be transported within blood plasma in an ionized state -Oxygen is soluble in water, but only in low amounts (most O2 is complexed to hemoglobin in red blood cells) -Lipids are non-polar and insoluble in water (transported in blood as lipoproteins)

Use of respirometry in measuring respiration rates

-It measures respiration rate--either by amount of CO2 produced or O2 consumed -A manometer can accomplish this by recording the pressure change (as a moving bubble in solution) that occurs when O2 is consumed (must include a CO2 absorbent)

Polarity of water

-It's made up of two hydrogen atoms covalently bonded to an oxygen atom -Oxygen atom has a high electronegativity and attracts the shared electrons more strongly -This results in polarity (the O atom is slightly negative, and the H atoms are slightly positive) -Because of this, water can form hydrogen bonds between the O of one molecule and the H of another

How is the structure of the intestinal villus related to its role

-Its primary role is to absorb digested products -Microvilli--Ruffling of epithelial membrane increases Sa -Rich blood supply--Capillary network transports absorbed products -Single layer epithelium--minimizes diffusion distance -Lacteals--Absorbs lipids from the intestine into the lymphatic system -Intestinal glands--exocrine pits release digestive juices -membrane proteins--facilitates transport of digested materials

List the functions of membrane proteins

-Junctions: Serve to connect and join two cells together -Enzymes: Fixing to membrane localizes metabolic pathways -Transport: Responsible for facilitated diffusion and active transport -Recognition: May function as markers for cellular identification -Anchorage: attachment points for cytoskeleton and extracellular matrix -Transduction: Function as receptors for peptide horomones Acronym: JETRAT

two methods for the treatment of kidney failure

-Kidney dialysis involves the external filtering of blood to remove metabolic waste -Blood is pumped through a dialyzer, which restricts passage of certain materials and introduces fresh fluid -The best long-term treatment for kidney failure is a kidney transplant -A transplanted kidney is grafted into the abdomen, but donors must be a close genetic match to minimize rejection

production of lactose-free milk and its benefits

-Lactose is fixed to agarose beads (lactase purified from yeast or bacteria) -Milk is passed over the immobilized enzyme, becoming lactose free -This milk provides a source of milk and other dairy products for lactose-intolerant individuals -increases sweetness in the absence of artificial sweeteners (monosaccharides are sweeter in taste) -Reduces the crystallization of ice-creams (monosaccharides are more soluble, less likely to crystallise)

role of ADH (vasopressin) in maintaining the water balance of the blood

-Level of water drawn from collecting duct is controlled by the hormone antidiuretic hormone (ADH) -ADH is released from the pituitary gland (posterior lobe) in response to dehydration -ADH produces water channels (aquaporins) to facilitate water reabsorption via osmosis -This means less water remains in the filtrate and the urine becomes more concentrated -when an individual is suitably rehydrated, ADH levels decrease and less water is reabsorbed

Flow of energy in an ecosystem

-Light energy is the initial energy source for almost all communities -It's converted into chemical energy (organic molecules) by producers / autotrophs via photosynthesis -the organic molecules are converted into usable energy (ATP) via cell respiration -Heterotrophs (consumers) ingest these organic compounds to undergo cell respiration -Energy transformations are only ~10% efficient--the majority is lost as heat

Key events in the light-dependent reactions (non-cyclic photophosphorylation)

-Light photoactivates chlorophyll within photosystem II (P680) and photosystem I (P700) -Electrons released from PSI are taken up by hydrogen carriers (forms NADPH) -Electrons released from PSII go through an electron transport chain (causing proton accumulation in thylakoids) -Protons return to the stroma via chemiosmosis through ATP synthase (producing ATP via photophosphorylation) -Electrons lost from PSI are replaced by PSII electrons, while PSII electrons are replaced by photolysis of water

How does the loop of henle maintain hypertonic conditions in the medulla

-Loop of Henle creates a salt gradient within the medulla -Descending limb is permeable to water but not salt -Ascending is inverse -Means as the loop descends into the medulla, the interstitial fluid becomes salty (hypertonic) -Additionally, blood in the vasa recta runs countercurrent to the filtrate, so salts in blood move towards the medulla (and water away) -as the collecting duct passes through the medulla, the salt gradient will draw water from the ducts (osmoregulation)

Functions and organization of the lymphatic system

-Lymphatic system is a transport system that protects the body by producing and filtering lymph -Lymph contains white blood cells and arises from the drainage of fluid from blood and tissues -Lymph is filtered at lymph nodes, where pathogens are removed before fluid is returned to venous circulation -Major lymphatic organs include the spleen, tonsils, thymus and adenoids

How are bioinformatic databases used to identify potential new drugs

-Malaria is caused by the protozoan Plasmodia (whose metabolism is controlled by specific enzymes) -Bioinformatic databases can be searched to identify molecules that structurally resemble specific substrates -Combinatorial chemistry can then be used to modify these molecules to form effective inhibitors -This modelling of desired chemicals is called rational drug design

How do electron micrographs support the Davison-Danielli model?

-Many micrographs show a 3-layer structure: two lighter, outer layers, and a darker, inside phospholipid layer in the middle -Although seeming like that could be right, the interpretation is often cited as incorrect

What is membrane fluidity?

-Means that the bilayer is not static and membrane components like proteins can move positions, allowing membranes to change shape

Suggest ways of measuring enzyme-catalyzed reactions: the breakdown of starch into maltose (by diastase)

-Measure color change with a colorimeter (starch is stained purple by iodine) -measuring volume change via dialysis tubing (starch is impermeable to tubing, maltose is not)

Suggest ways of measuring enzyme-catalyzed reactions: digestion of pectin in cell walls (by pectinase)

-Measuring volume of liquid produced as a consequence of the breakdown in cell wall -measure the digestion of pectin via percentage weight change

Evidence supporting endosymbiosis

-Membranes: Chloroplasts/mitochondria have double membranes -Antibiotics: Chloroplasts/mitochondria susceptible to certain antibiotics -Division: Chloroplasts/mitochondria divide by a fission-like process -DNA: Chloroplast/mitochondria have own circular DNA -Ribosomes: Chloroplasts/Mitochondria have 705 ribosomes Acronym: MAD DR

How do the results of Meselson-Stahl's experiment support semi-conservative DNA replication

-Meselson and Stahl treated DNA with a heavier nitrogen isotope (15N) and then replicated the presence of a lighter nitrogen isotope (14N) so template DNA and newly synthesized DNA could be differentiated -Results supported a semi-conservative model of DNA replication: -After one division, all molecules contained both 15N and 14N -After two divisions, some molecules contained both 15N and 14N, while other molecules only contained 14N

Three types of RNA

-Messenger RNA (mRNA)--An RNA copy of a DNA -Transfer RNA (tRNA)--Transfers amino acids to the ribosome -Ribosomal RNA (rRNA)--The catalytic component of ribosomes

production of methane by methanogens and its oxidation in the atmosphere

-Methanogens produce methane from organic matter as a by-product of ANAEROBIC respiration -the methane can either diffuse into the atmosphere or accumulate within the ground (natural gas deposits) -Methane in the atmosphere is oxidized to CO2 and H2O after ~12 years

Outline structural organization of carbs (monomer -> polymer)

-Monosaccharides are joined together by condensation reactions to form polysaccharides (water produced) -Covalent bond connecting the monosaccharides together is called a glyosidic linkage -Polysaccharides can be digested into smaller oligosaccharides via hydrolysis reactions (water is required)

Role of pollinators in plant reproduction

-Most flowering plants will use mutualistic relationships with pollinators to reproduce -The plant plants use a mechanism of pollen transfer, while the animal gains source of nutrition (ex: nector)

xylem structure and purpose

-Moves materials via the process of transpiration -Transports water and minerals unidirectionally -xylem occupy the inner portion of the vascular bundle -Vessel wall made of fused cells (continuous tube) -Vessels are hollow with no cell content

Consequences of base substitution mutation and the development of sickle cell anemia

-Mutation changes GAG to GUG on the mRNA transcription -Mutation affects the 6th codon of the hemoglobin beta chain gene -the mutation changes the amino acid from Glutamic acid to valine -This causes the hemoglobin to form insoluble strands, which causes them to clump together -The red blood cells adopt the characteristic of a sickle cell shape -The sickle cells break down, leading to anemia and reduces O2 transport -the sickle cell mutation demonstrates co-dominance -The trait shows heterozygous advantage (resistance to malaria)

Osmosis

-Net movement of free water molecules across a semi-permeable membrane from a region of low solute concentration to a region of high-solute concentration until equilibrium is reached

Five types of white blood cells

-Neutrophils: rapid response to microbial infections -lymphocytes: specific (adaptive) immune response -monocytes / macrophages: longer lasting response to microbial infections -eosinophils: target multicellular parasites (too big for phagocytes) -basophils: involved in inflammation (similar to most cells) Acronym: Never Let Monkeys Eat Bananas

How do non-competitive inhibitors affect enzyme activity

-Non-competitive inhibitors bind to a site other than the active site (called an allosteric site) -These inhibitors cause a conformational change in the enzyme, which alters the shape of the active site -Thus the substrate can no longer bind (increasing substrate concentration will have no effect on inhibition)

how can non-disjunctions give rise to aneuploidy

-Non-disjunction describes the failure of chromosomes to separate during cell division -If non-disjunction occurs in anaphase I, all four gametes will be affected (two=n+1; two = n-1) -If it occurs in anaphase II, only two of the gametes are affected (two = n; one = n+1; one = n-1) -If a gamete with one extra chromosome fuses with a normal gamete, the offspring will have trisomy

Role of nucleosome in the regulation of gene expression

-Nucleosomes are involved in the supercoiling of DNA (supercoiled DNA is inaccessible for transcription) -Acetylation of the histones make the DNA less tightly coiled (increases gene expression) -Methylation of the histones makes the DNA more tightly coiled (decreases gene expression)

Label an animal cell

-Nucleus is the bigger sphere in the cell -Nucleolus is the smaller sphere -rough ER is the ER closer to the nucleus -Smoother ER is farther from the Nucleus -mitochondrion is the bean near the smooth ER (important for ATP production) -lysosome is near the golgi apparatus, and looks like a small potato -Golgi apparatus is the big thing with the many curved lines -Plasma membrane is on the outside of the cell -ribosomes are the small dots all across the cell -cytoskeleton /cytosol are the cytoplasm

Which blood group is the universal donor and acceptor

-O is the universal donor -AB is the universal acceptor

Lateral meristems

-Occurs at the cambium -Responsible for secondary growth (width) -Produces secondary xylem and phloem -Produces the bark on trees

Apical Meristems

-Occurs at the tips of roots and shoots -Responsible for primary growth (adds length) -develops into primary xylem and phloem -produces new leaves and flowers

Allopatric speciation

-Occurs when a geographical barrier physically isolates populations of an ancestral species -the two populations begin to genetically diverge until they can no longer interbreed (speciation)

Artificial selection

-Occurs when humans make a determination to select for some traits over others (via genetic modification or selective breeding) -Think of crops and how they're selected for

temporal reproductive isolation

-Occurs when two populations differ in their periods of activity or reproductive cycle ex: leopard frogs and wood frogs reach sexual maturity at different times in the spring and hence cannot interbreed

formation of fossil fuels: oil/natural gasses

-Oil and natural gas form as the result of the decay of marine organisms on the ocean floor -Sediments are deposited on top of the organic matter, creating anoxic conditions that prevent decomposition -The compacted and heated organic matter forms oil and gas, which accumulates within porous rocks

Organic v inorganic compounds

-Organic molecules contain carbon and are synthesized by living organisms (everything else is inorganic) -Exceptions include carbides, carbonates, oxides of carbon and cyanides

anaerobic respiration

-Oxygen not required -Only 2 ATP yield -products: -Animals: Lactic acid Plants: ethanol and CO2 Location: Cytosol

Aerobic respiration

-Oxygen required -High yields (36-38 ATP) -Products: CO2 and H2O -Happens in the Cytosol and mitochondria

Systematic circulation

-Oxygenated blood returns from the lungs (via pulmonary vein) to the LEFT side of the heart -It is pumped (by left atrium/left ventricle) to the body via the aorta

purpose and process of the polymerase chain reaction (PCR)

-PCR is used to rapidly amplify minute quantities of DNA -It involves a thermal cycler and three repeating steps: -Denaturation: DNA is heated to separate strands -annealing: primers are introduced to designate copying points -Elongation: TAQ polymerace (heat resistant so it does not denature from heat) synthesizes new strand -These three steps double the amount of DNA, so a typical reaction of 30 cycles will produce over 1 billion copies of desired DNA sequence

Purpose and process of the polymerase chain reaction (PCR)

-PCR is used to rapidly amplify minute quantities of DNA -It involves a thermal cyler and three repeating steps 1: Denaturation: DNA is heated to separate strands 2: Annealing: primers are introduced to designate copying points 3: elongation: Taq polymeras--with heat resistance to avoid denaturing during PCR--synthesize the new strand -These three steps double the amount of DNA, so a typical reaction of 30 cycles will produce of 1 billion copies of desired DNA sequences

Sexual reproduction results in diploid zygotes with two alleles for each characteristic

-Parents each pass on one copy of every chromosome to offspring via haploid gametes -The resulting zygote is diploid and therefore possesses two copies of every gene -These alternative copies of genes are called alleles

Process of facilitated diffusion

-Passive transport mechanism for materials that cannot freely cross the membrane -Large and charged substances cannot freely cross the bilayer (ions, macromolecules) -Membrane-bound proteins help them cross (ex: channel proteins forming hydrophilic pores)

Passive v active transport

-Passive: movement from a region of higher concentration to a region of lower concentration along a gradient, and does not require the use of ATP--ex: simple diffusion, facilitated diffusion, osmosis -Active transport: Movement from a region of low concentration to a region of higher concentration (against the gradient) and requires the use of ATP--Ex: membrane proteins (integral) (protein pumps)

differentiate between phagocytosis and pinocytosis

-Phago: process by which solid substances are ingested (ex food particles) (usually brought to lysosome to be broken down) -Pino: process by which liquids/solutions (dissolved substances for example) are ingested by cell (allows for quick entry in large amounts)

how do phagocytic leukocytes ingest and present pathogens in the blood and body tissue

-Phagocyte (macrophages) circulate in blood but move to tissue upon infection -pathogens are engulfed by the phagocyte and internalized in a vesicle -the vesicle may then fuse with a lysosome to digest the pathogen -Antigenic fragments from the pathogen are presented on the macrophage -These fragments are then presented to lymphocytes to help stimulate the production of specific antibodies

five non-specific defense mechanisms the body uses to combat infection

-Phagocytosis: pathogens are engulfed and destroyed by phagocytic leukocytes -inflammation: blood flow is increase to site of infection to increase leukocyte access -complement proteins: active a cascade that promotes pathogen detection and destruction -Fever: increase body temp. to assist in pathogenic destruction -natural killer cells: non-specifically target viral-infected cells

structure of the phloem

-Phloem tubes are composed primarily of two main types of cells: sieve elements and companion cells -Sieve elements are long, narrow cells connected by porous sieve, with no nuclei and reduced organelles - companion cells sustain the sieve elements and possess an infolding plasma membrane to increase SA:Vol ratio -Plasmodesmata connect the two cell types to mediate symplastic exchange

melatonin in controlling circadian rhythms

-Photoreceptors detect light and send signals to the hypothalamus -Light exposure inhibits the melatonin secretion from the pineal gland (hence, increased melatonin rates at night) -High levels of melatonin promote sleep in diurnal animals (ex: humans)

hormonal role of the placenta

-Placenta takes over hormonal role as corpus luteum degenerates -Estrogen stimulates growth of the uterine myometrium and mammary glands -progesterone maintains the endometrial lining and reduces uterine contractions

Why is the osmolarity of a solution affecting animal and plant cells differently

-Plant cells have rigid cell walls which prevent uncontrolled osmosis -Plant cells may swell, but they cannot burst or rupture like animal cells -Equally, the cell membrane may shrink from the cell wall, but overall structure remains in tact

Role of auxin in phototropism in both the shoots and roots

-Plant tropisms are caused by a differential elongation of cells in response to stimulus -Auxin controls rates by changing patterns of gene expression in plant cells -In shoots, auxin promotes cell elongation, while in roots, auxin inhibits cell elongation -Plant turns away from side with cell elongation, so the shoots grow towards light (positive tropism) and the roots grow away from light (negative tropism)

Five differences between plant and animal cells

-Plants may have chloroplast, while animals dont -plants have cell walls while animals dont -plant cells have larger, central vacuole whereas animal cells have small, temporary vacuoles, if even -animal cells have cholesterol in their plasma membrane, plants don't -plant cells store excess glucose as starch, while animals store is as glycogen

how are stem cuttings used to clone plants

-Plants retains pluripotent cells (called meristem) and can reproduce asexually via vegetative propagation -hence new plant clones can be grown from stem cutting

Two types of vectors for gene transfer

-Plasmids -Viruses

Role of plasmids in bacterial cells

-Plasmids are circular DNA molecules capable of autonomous replication and transcription -They can be transferred between bacteria via bacterial conjugation -They are also used as a vector for gene transfer in scientific experiments

Outline the role of vesicles in the transport of materials between organelles

-Polypeptides destined for secretion are synthesized by ribosomes on rough ER -They are transported to the Golgi body via vesicles (formed from ER membrane) -Golgi body potentially sorts, stores, and modifies these secretory products -The proteins are then transported by another vesicle to the cell membrane for secretion -External materials can be internalized into cellular vesicles via endocytosis (for digestion by lysosome)

cnidaria (invertebrate)

-Possess radial symmetry -Have mouth but no anus (single opening) -Has tentacle and stinging cells (cnidocytes) Ex: cool-looking jelly

events that precede the meiotic divisions of a developing egg cell

-Process begins during fetal development, when a large number of primordial cells are formed by mitosis -Primary oocytes remain arrested in prophase I until puberty, when a girl begins her menstrual cycle -Each month, hormones unlock some oocytes to begin the second meiotic division (but are arrested in metaphase II) -If the oocyte is fertilized by a sperm, meiosis II is completed and the mature egg form an ovum

Pancreas

-Produces a broad spectrum of enzymes that are released into small intestine via the duodenum -Also secretes a certain hormones (insulin, glucagon), which regulate blood sugar concentrations

differentiate between prokaryotes and Eukaryotes

-Prokaryote's dna is naked, molecules are circular, dna is freely floating, doesn't have organelles, ribosomes are 70S in size, reproduce by binary fission, reproduction is asexual (cells haploid) and are the smaller of the two -Eukaryotic cells' dna are bound to histone protein, dna molecules are linear, dna is contained within the nucleus, has membrane-bound organelles, 80S in size, may reproduce via numerous methods, reproduction can be sexual or asexual (diploid cells like ovum and sperm) and are larger than prokaryotes

Lamarck's theory of evolution

-Proposed that organisms evolved new characteristics as a consequence of habitual use or disuse -Ex: a giraffe willed its neck longer and longer to reach the leaves

Darwin's theory of evolution

-Proposed that organisms randomly develop new characteristics that were passed on for being beneficial -Ex: long-necked giraffes survived over short neck giraffes because they could reach more leaves

Why are carbs and lipids better than proteins for an energy source

-Protein digestion produces nitrogenous waste (bc of the presence of an amine group) -Nitrogenous wastes are toxic to cells (must be removed via excretion to the kidneys)

Bound (ER) versus free (Cytosolic)

-Proteins synthesized by bound ribosomes have different destinations to those synthesized by free ribosomes -ER-bound ribosomes = secretory proteins (or lysosome) -Free ribosomes = intracellular proteins

why are energy pyramids shaped as pyramids?

-Pyramids of energy show the amount of energy at each trophic level of the food chain -They will never appear inverted as some of the energy at each trophic level is always lost -Each level should be roughly 1/10 of the size of the previous level -Producers will always occupy the bottom

two methods of population sampling

-Quadrats -Transects

process of transcription, including the role of RNA polymerase

-RNA polymerase attaches to the promoter (requires the presence of transcription factors) -RNA polymerase unwinds the DNA and separates the strands -Nucleoside triphosphates (NTPs) align opposite complementary bases and are joined by RNA polymerase This continues until the terminator at which point the enzymes and transcript dissociate from the DNA

Role of RNA polymerase in the process of transcription

-RNA polymerase unwinds and separates the double stranded DNA and then synthesizes a new RNA strand -Based on the antisense template, the RNA strand is then released and the DNA double helix reforms

impact of non-competitive inhibitors on reaction rate GRAPH

-Rate of reaction is slowed -Maximal rate of reaction is less -Increasing substrate concentration will NOT increase maximum reaction rate

Role of cholesterol in animal membranes

-Reduces membrane fluidity (immobilizes phospholipids at higher temp.) -reduces membrane permeability (to hydrophilic ions) -prevents crystallization (increases flexibility at lower temps)

how to tell if muscle fibers are contracted or not

-Relaxed if there is a visible H band and wide I band -Contracted if there is a narrow I band and no H zone

specific example of competitive inhibitors

-Relenza is a drug designed to treat infection with the influenza virus -Influenza virions tether to infected cells via hemagglutinin and are released by the enzyme neuraminidase -Relenza competitively inhibits the neuraminidase active site, preventing cleavage from hemagglutinin -Thus virus cannot be released and the spread of infection is diminished

Three therapeutic examples of stem cells

-Replace dead nerve cells in individuals with Parkinson's disease (Freed et al, 2001) -Replace bone marrow in individuals with leukemia (cancer of the blood) -replace pancreatic beta cells in individuals with type 1 diabetes (cannot regulate blood sugar)

Process of translation

-Ribosome binds to mRNA and moves along it in a 5' - 3' direction, reading the sequence in codons -Each codon encodes a specific amino acid, which is brought to the ribosome by tRNA molecule -Each tRNA is specific for a particular codon because of the presence of a complementary anticodon -The tRNA molecules bring the amino acids to the ribosome in an order the codon sequence determined -The ribosome moves along the mRNA, joining the amino acids together via peptide bonds -Translation of a polypeptide begins at a START codon (AUG) and it finishes at a STOP codon

role short tandem repeats (STRs) play in DNA profiling)

-STRs are short repeating sequences in non-coding DNA -Different individuals have different numbers of repeats, so by comparing STR loci, unique profiles emerge

Label the parts of the digestive system

-Salivary glands -(O)esophagus -Liver -Stomach -Gall bladder -Pancreas -Small intestine -Large intestine

three potential applications of the completed Human Genome Project

-Screening for known genetic conditions -Discovering new drug treatments and medications (ex: phamacogenomics) -Establishing ancestral lineage

Type II pneumocyte

-Secrete pulmonary surfactant -Reduces surface tension within alveoli (easier to inflate alveoli, preventing collapse)

evidence for evolution provided by selective breeding

-Selective breeding involves the international mating of animals with desired characteristics (artificial selection) -As human intervention drives the selection process, changes will occur over fewer generations and will promote the evolution of phenotype extremities (hence, easier to identify the evolutionary pathway) -Examples: horses bred for speed vs power, cows (Belgian blue = muscle mass), large variations of dogs

Different methods of biological classification: artificial

-Selects unifying characteristics first and then groups organisms accordingly -Easy to develop and relatively stable (unlikely to change) but don't show evolutionary relationship

Two qualities of Stem cells

-Self renewal: Stem cells are capable of continues division -Potency: Stem cells are capable of differentiation (are effectively unspecialized precursors)

two key qualities of plasma membranes

-Semi-permeability (some things an cross the membrane, other things can't cross) -Selectivity (cells can control the passage of certain materials across the membrane)

role of tandem repeats in DNA profiling

-Short tandem repeats (STRs) are short repeating segments within satellite DNA -the number of repeats for a particular loci will differ between individuals -the STRs can be excised and separated on a gel to create a distinct DNA profile of a given individual (the more STR loci included in the profile, the more unique the DNA profile will be for the individual)

Three functions of carbs in cells

-Short-term memory energy source (ex glycogen and starch) -Structural component (ex cellulose in plant cell walls) -Cell recognition and signalling (ex glycoproteins in plasma membranes

Items moved by simple diffusion v facilitated transfusion

-Simple diffusion: O2, CO2, lipophilic substances (ex: steroids) -Facilitated transfusion: Ions (Sodium, potassium, etc) and macromolecules (glucose, starch, etc)

Differentiate between the 3 classes of lipids

-Simple lipids: Triglycerides -Compound lipids: phospholipids, sphingolipids, etc -Derived lipids: steroids, cholesterol

role of surface barriers in the physical protection against infection

-Sin protects external structures and is a thick and dry region composed predominantly of dead cells -Mucous membranes protect internal cavities and is a thin region composed of living cells that secrete mucus -Sebaceous glands secrete biochemical agents / acids to inhibit bacterial growth -Commensals (gut bacteria) prevent the colonization of harmful pathogens in the digestive tract

structure of a muscle fiber

-Skeletal muscles consist of bundles of muscle fibers (formed of fused cells) that have key characteristics -Multinucleated: muscle fibers are formed from multiple individual muscle cells fusing together -Large number of mitochondria: contractions requires a lot of mitochondria -Tubular myofibrils: Tubular myofibrils run the length of the fiber and are responsible for contraction -Sarcolemma: The sarcolemma is the continuous membrane surrounding a muscle fiber -Sarcoplasmic reticulum: internal membrane network that is specialized for muscle contractions (high calcium)

How is carbon stored in aquatic ecosystems

-Some CO2 in water stays as dissolved gas, however most reacts to form hydrogen carbonate ions -When the ions come into contact with rocks/sediments, they commonly form calcium carbonate (limestone) -In animals, the calcium carbonate can be used to form hard exoskeletons (ex: coral and shells)

how is water transported around the plant via a transpiration stream

-Some of the light energy the leaves absorb change into heat, converting water to vapor -the vapor diffuses out and is evaporated, creating a negative pressure gradient in the leaves -The xylem draws new water from roots (which enter from soil via osmotic uptake) -Water rises up (against gravity) through xylem vessels via mass flow because of cohesion and adhesion -The flow of water from the roots to the lead (via xylem) is called the transpiration system

phyletic gradualism

-Speciation occurs following continuous change at a constant pace over a long period of time -Arises via a gradual accumulation of mutations (big changes result from many small changes)

Punctuated equilibrium

-Speciation occurs rapidly in bursts with long periods of stability in between -In stable periods, characteristics are maintained, but this is punctuated by periods of environmental change

metaphase I

-Spindle fibers from opposing centrosomes connect to bivalent (at centromeres) and align them along the middle of the cell

Digestion of starch (and subsequent transport of products)

-Starch is composed of glucose monomers in either linear (amylose) or branched (amylopectin) arrangement -Amylase is an enzyme that digests starch (amylose into maltose; amylopectin into short dextrin chains) -The pancreas plays a fundamental role in the digestion of starch molecules -It secretes amylase and hormones (insulin and glucagon)that regulate glucose uptake by the liver

application of stem cells to treat stargardt's disease

-Stargardt's disease is caused by a gene mutation that impairs photoreceptor cells in the retina -this leads to genetically inherited macular degeneration, resulting in blindness -May be treated by replacing damaged retinal cells with healthy ones derived from stem cells

what are the therapeutic use of stem cells

-Stem cells can be used to replace damaged/diseased cells with healthy ones -Stem cells can be harvested from embryos, umbilical cord blood or certain adult tissues like bone marrow -Biochemical solutions are used to trigger the differentiation of stem cells -cells are surgically implanted into patient's own tissue and the host immune system is suppressed to prevent rejection of cell

Five different functions of lipids

-Storage of energy (ex: triglycerides) -Hormonal role (ex: steroids) -Insulation (ex: sphingolipids) -Protection of organs (ex: triglycerides, waxes) -Structural components (ex: phospholipids) Acronym: SHIPS

seven functions of protein, providing an example for each

-Structure (ex: spider silk, collagen) -Hormones (ex: insulin, glucagon) -Immunity (ex: antibodies) -Transport (ex: hemoglobin) -Sensitivity (ex: rhodospin) -Movement (ex: actin, myosin) -Enzymes (ex: catalase, Rubisco) Acronym: SHITSME

How can polyploidy result in a speciation event

-Sympatric speciation is most commonly caused as the result of a meiotic failure during gamete formation -I meiotic cells fail to undergo cytokinesis, chromosomal number will double in the gamete (diploid not haploid) -This results in offspring that has an additional set of chromosomes (polyploidy) -Speciation will result if the polyploid offspring are fertile but cannot interbreed with the parent population -More common in plants that can self-fertilize and reproduce asexually (vegetative propagation)

Systole and diastole

-Systole described the period of heart contraction -Diastole describes the period of heart relaxation

Liver

-Takes the raw materials the small intestine absorbed and uses them to make key chemicals -Its role includes detoxification, storage, metabolism, bile production and hemoglobin breakdown

two factors in denaturation

-Temp. as thermal energy breaks hydrogen bonds responsible for tertiary structure which results in loss of function -pH as amino acids are zwitterions--possessing both positive and negative regions (amine and carboxyl groups)--so altering the pH will change the charge and solubility of the proteins, changing the structure

Effects of different factors on the rate of photosynthesis: temperature

-Temperature affects enzyme activity (enzymes control photosynthesis) -Activity initially increases as a rise of kinetic energy results in more frequent collisions -Above a certain temperature, activity decreases as enzymes denature

Somach

-Temporary storage tank where food is mixed by churning and protein digestion begins -It is lined by gastric pits that release digestive juices, which create an acidic environment

effects of HIV on the immune system

-The Human immunodeficiency virus (HIV) is a retrovirus that infects helper T cells -HIV is integrated into the genome of T cells and after years of inactivity the virus spreads -Infected TH cells are lysed (destroyed) to release the virus from the cells -This results in reduced immunity (AIDS) as antibody production is compromised

Role of the medulla and epinephrine (adrenaline) in regulating heart beat

-The SA node (pacemaker) maintains the heart's normal sinus rhythm (60-100 bpm) -The peacemaker may be regulated by the medulla (brainstem), with sympathetic nerves increasing heart rate -By releasing noradrenaline and parasympathetic nerves decreasing the heart rate by releasing acetylcholine -Heart rate may also be increased by the release of epinephrine (aka adrenaline) into the bloodstream

antibody production

-The antigenic fragments of pathogens are presented on the macrophages -lymphocytes are a class of white blood cells that develop in the bone marrow -macrophages present antigen fragments to helper T lymphocytes (TH cells) -TH cells release cytokines to activate an antigen-specific B lymphocyte (B cell) -The B cell divides and differentiates into plasma cells that produce antibodies -A small portion of clones develop into memory cells (for long-term immunity)

Catabolism

-The break down of complex molecules into simple subunits (monomers) -Requires hydrolysis reactions to proceed (water consumed as part of the reaction) -Ex: cell respiration

Anabolism

-The build up of complex molecules from more simple subunits (monomers). -Requires condensation reactions to proceed (water is produced as a by-product). -Ex: photosynthesis

mitosis

-The division of a nucleus to produce two genetically identical daughter cells (diploid -> diploid) -Mitosis occurs in human body cells and result in cloned copies

role of hormones and positive feedback in the process of birth

-The fetus begins to stretch the uterine walls, which trigger the release of two hormones: oxytocin and estrogen -Estrogen inhibits progesterone (which was preventing contractions) and oxytocin stimulates uterine contractions -As the uterus contracts, stretch receptors are further stimulated (positive feeback) -Contractions will stop when the baby is birthed (no more stretching of the uterus)

four different types of basis in nucleic acids

-The four DNA basis are: Guanine (G), Cytosine (C), Adenine (A) and Thymine (T) -RNA has uracil (U) instead of thymine -G and A are double-ringed purines, while C, T, and U are single0ringed pyrimidines -G and C pair via three hydrogen bonds; A and T/U pair via two hydrogen bonds

how is biochemical evidence used to demonstrate evolutionary relationships

-The genetic code is (almost) universal and hence DNA and protein can be compared to determine relatedness -mutations naturally accumulate and so sequence differences demonstrate the degree of divergence -more similar the base sequence, the more likely the two species are to be related) -Non-coding DNA mutates the fastest, followed by gene sequences, with amino acid sequences mutating slowest.

How does the universality of genetic code allow for gene transfer

-The genetic code is universal, meaning (almost) all organisms follow the same set of genetic instructions -This means that a DNA sequence from one organism can be successfully translated by another organism -Example, the gene for insulin is extracted from human cells and inserted into bacterial cells -The bacteria can now produce human insulin, as they reproduce very quickly -This can be used for the production of insulin for people with type I diabetes

primary protein structure

-The order / sequence of amino acids within a polypeptide chain -formed via peptide bonds between the amine and carboxyl groups of adjacent amino acids -Primary structure determines all subsequent levels of protein structure

Tertiary protein structure

-The overall three-dimensional shape of the polypeptide chain -Formed via a variety of bonds / interactions between the variable side chains (R groups) -These interactions may include hydrogen bonds, ionic bonds, disulphide bridges or hydrophobic interactions

humoral immunity

-The pathway by which antibodies are produced by plasma cells to target exogenous antigens -Antigens are presented on the MHC class II markers of macrophages to helper T cells -The helper T cells then secrete cytokines to activate the appropriate B lymphocytes -The specific B cells divide and differentiate (clonal selection) to form antibody producing plasma cells

cell mediated immunity

-The pathway that does not result in antigen production but instead targets endogenous antigens -Cancerous and virus-infected cells involve the body's own cell and thus are not recognized as foreign -These cells present antigenic fragments as a complex with their own self markers (MHC class I) -When helper T cells identify these cells, they stimulate cytotoxic T cells that lyse the compromised cells

How are the properties of phospholipids used to maintain the structure of a cell membrane?

-The phospholipids form a bilayer -The hydrophilic phosphate face outwards into the aqueous solutions (intracellular and extracellular) -The hydrophobic fatty acid tails face inwards and are held in place by weak hydrophobic associations -because the associations are weak, phospholipids are able to move within the bilayer (membrane fluidity)

How does the structure of the placenta relate to its function

-The placenta is a disc-shaped structure that nourishes the developing embryo -It is formed from the trophoblast of a developing embryo (outer layer) -An umbilical cord connects a fetus to the placenta and maternal blood pools via open-ended arterioles into lacunae -Fetal chorionic villi extends into these lacunae and facilitate maternal exchange

label a prokaryotic cell

-The plasmid is the little clothes hanger thing -The glycocalyx is the slime capsule -cell membrane is the membrane of the cell -nucleoid is the little bundle of things on the image that are the DNA, but not bound to a nucleus -Cell wall is the little shadow under the membrane -Flagellum is the little tail on the end

Trophic level

-The position of an organism occupies within a feeding source -Producers always occupy the first level

Quaternary protein structure

-The presence of multiple polypeptides or prosthetic groups to form a biologically active protein -Not all proteins have this structure

Purpose of meiosis

-The process by which sex cells (gametes) are made in the reproductive organs -It involves the reduction division o fa diploid germline cell into four genetically distinct haploid cells

Light-independent reaction

-The products of the light-dependent reaction (NADPH and ATP) are used in the light-independent reaction -These reactions fix carbon (from CO2) to form organic molecules (such as carbohydrates)

repolarization

-The restoration of a membrane potential following depolarization (i.e. restoring a negative internal charge) -involves K+ channels opening

Genetic factors

-The sex chromosomes will determine sex: Females have XX, males have XY -Y chromosome contains SRY gene that causes gonads to develop into testes (in its absence, ovaries develop)

Tropism and 2 examples

-The turning of an organism in response to a directional external stimulus Phototropism: growth response to light Geotropism: growth response to gravity

How did florey and chain demonstrate the antibiotic properties of penicillin

-The use of penicillin as a viable antibiotic was shown by florey and chain (1940)

How many different amino groups are there and how are they different

-There are 20 different groups within nature -They're different according to the chemical composition of their variable side chain (the 'R' group) NOTE: you will not have to memorize all 20, only that there are 20

What are the four processes needed for the spontaneous origin of life on earth

-There was non-living synthesis of simple organic molecules (from primordial inorganic molecules) -These simple organic molecules became assembled into more complex polymers -Certain polymers formed the capacity to self replicate (enabling inheritance) -These molecules became packaged into membranes with a distinct internal chemistry (protobionts)

role of thyroxin in body temp. regulation

-Thermoreceptors (in skin) send signals to the hypothalamus and thyroxin is released from the thyroid gland -Thyroxin increases the basal metabolic rate (which generates heat) -When body temp. is low, thyroxin is released, and when temp. is high, thyroxin is not released

Challenges to cell theory: muscle fibres

-They are fused cells, so they're long and have multiple nucleus -challenges cells are autonomous units

function of the genetic code

-This is a set of rules by which information encoded by mRNA is translated into polypeptides -Amount of specific amino acid encoded by each triplet of mRNA bases are identified (codon) -There are 64 possible codon combinations, but only 20 possible amino acids -This means some codons code for the same amino acid (degeneracy)

how does the myelin sheath enable salutatory conduction

-This myelin sheath functions to improve transmission speed (via saltatory conduction) -The action potential 'hops' between the gaps in the myelin sheath (called nodes of Ranvier) -This increases transmission speed by ~100x

DNA polymerase

-This synthesizes a new strand (complementary to the template strand) -Nucleotides align opposite their partner, and DNA Pol III covalently joins them together -DNA Pol III synthesizes a new strand in a 5' - 3' direction

How do sodium-potassium pumps work?

-Three sodium ions attach to intracellular binding sites on the protein pimp -ATP hydrolysis phosphorylates the pump and changes its conformation -Sodium ions are translocated and released from the cell, exposing extracellular binding sites from K -Two K ions attach to these sites and the pump is dephosphorylated -this returns the pump to its original condition

The four processes that involve mitosis

-Tissue repair -Organismal growth -Asexual reproduction (ex: vegetative propagation) -Development of an embryo Acronym: toad

Metabolism

-Totality of all enzyme-catalyzed reactions in a cell or organism

Differentiate totipotent, pluripotent, multipotent, and unipotent stem cells

-Totipotent: can form any cell type AND form extra-embryotic structures (can form new organism), ex: blastocyst (baby ones) -Pluripotent: Can form any cell type, but not extra embryotic structures, ex: embryotic stem cells (extra baby ones) -multipotent: can differentiate into closely related cell types, ex: hematopoietic stem cells (bone marrow) form a variety of blood cells -Unipotent: can divide but not differentiate, ex: muscle cells can self-replicate

role of the promoter and transcription factors in the regulation of transcription

-Transcriptional activity is regulated by transcription factors which mediate binding of RNA polymerase to the promoter (the initiation point for transcription of a gene sequence) -the presence of certain transcription factors may be tissue-specific (explaining why different genes are activated in different tissues) and environmentally sensitive (explaining why expression patterns can change)

Explain the Nicolson-Singer model

-Transmembrane proteins are embedded within a phospholipid bilayer -This model is referred to as the "fluid-mosaic model"

genetic conditions that cause Down Syndrome and identify contributing factors

-Trisomy 21 causes it -increased maternal age increases risk of non-disjunction

Explain the Davson-Danielli model

-Two layers of protein flank a central phospholipid bilayer -This model is also referred to as a "lipo-protein sandwich"

function of the pulmonary surfactant

-Type II Pneumocytes secrete pulmonary surfactant which reduces the surface tension in alveoli -As alveoli expand with gas intake, the surfactant becomes more spread out across the moist alveolar lining -this increases surface tension and slows the rate of expansion, ensuring all alveoli inflate at the same time

Meristems

-Undifferentiated cells in plants capable of indeterminate growth (analogous to stem cells) -Meristematic tissues have specific regions of growth in plants (allows regrowth of vegetative propagation)

the role and location of valves in the circulation of blood

-Valves in veins and the heart ensure the circulation of blood is unidirectional by preventing back flow -Heart valves include AV valves (tricuspid and bicuspid) and semilunar valves (pulmonary and aortic)

Theory of vitalism and how it was falsified

-Vitalism proposed that organic molecules could ONLY be synthesized by living organisms -Fredrick Woehler falsified it in 1828 -He was able to synthesize urea from an inorganic salt under lab conditions

thermal properties of water

-Water molecules can form extensive hydrogen bonding between molecules, which requires energy to break -This means it takes a lot of thermal energy to change temp. (state) of water -Hence, water has a high heat capacity (and high heat of vaporization/fusion)

The Miller-Urey experiment demonstrated that

-Water was boiled to vapor to reflect the high temps. common to earth's original conditions -The vapor was mixed with a variety of gases to create a reducing atmosphere (no o2) -This mixture was then exposed to an electrical discharge (simulating effects of lighting as energy source) -The mixture was then allowed to cool (concentrating components) and left for a period of one week -Later, the condensed mixture was analyzed and found to contain traces of simple organic molecules -Supports idea came from an intense electric impulse

How did Watson and Crick propose the structure of DNA via model making

-Watson and Crick used the above knowledge and constructed DNA models through trial and error -They demonstrated that DNA strands were antiparallel and formed a double helix -They also showed complementary base pairings

how does immunity occur

-When a B lymphocyte divides to form plasma cells, a small portion will differentiate into memory cells -Memory cells are long living and survive many years, producing low levels of circulating antibodies -If re-infection occurs, memory cells produce antibodies faster so disease does not develop (immunity)

combustion of hydrocarbons

-When hydrocarbons are heated in the presence of oxygen, they undergo a combustion reaction to release CO2 and H2O as a by-products (this reaction is exergonic--produces energy) -Sources of combustible hydrocarbons include biomass and fossilized organic matter (fossil fuels)

how does random gamete fusion promote variation within a species

-When two haploid gametes fuse, they form a diploid zygote which can grow a new organism -Because gamete fusion is random, each successive offspring will be composed of a distinct combination of maternal and paternal chromosomes -This means every member of a species is unique (promoting biodiversity)

Cohesion in relation to water

-When two identical molecules 'stick' together (via intermolecular bonding) -Water molecules are cohesive (they an 'stick' together via hydrogen bonding)

early development of an embryo

-Zygote undergoes several divisions to form a morula and subsequent unequal divisions results in a blastocyst -Blastocyst contains an inner cell mass (forms embryo), outer layer (trophoblast: forms placenta) and a cavity -Occurs in the oviduct and when the blastocyst reaches the uterus, it embeds into the endometrium

nutrient

-a substance (found in food) used by an organism to survive, grow and reproduce -There are 6 major nutrients: carbs, lipids, proteins, vitamins, minerals, and water

the secretion and reabsorption of acetylcholine

-acetylcholine is a neurotransmitter that serves excitatory and inhibitory function--it is used to stimulate -muscular contractions and it also promotes parasympathetic responses -Acetylcholine is broken down in synapses by acetylcholinesterase (AChE) to prevent overstimulation of receptors

Sense v antisense strands

-antisense strands are the DNA strand that ARE transcribed (complementary to eventual RNA sequence) -Sense strand is the strand that is NOT transcribed (identical to the RNA sequence - except the DNA strand has T and not U)

sex linkage ( ͡° ͜ʖ ͡°) and two examples

-any gene/trait that is located on the sex chromosome ( ͡° ͜ʖ ͡°) -Example 1: Hemophilia example two: red-green color blindness

how can aphid stylets be used to measure translocations rates

-aphids are insects that feed on sap in phloem via a stylet (which can be severed to collect the sap) -if plants are exposed to radioactive CO2, they will produce radioactively labelled sugars -translocation rate can be identified by the time taken for radioisotopes to be detected at various points

role of leptin in the control of appetite

-appetite suppression is regulated by the hormone leptin (secreted by adipose tissue) -leptin binds to receptors in the hypothalamus to inhibit/suppress appetite (lower food intake = lower weight gain) -Over-eating causes more adipose cells to be produced, so more leptin is released, leading to desensitization

capacitation

-biochemical changes occur when sperm enters the female reproductive tract -Uterine chemicals dissolve the sperm's cholesterol coat, improving its motility

How are different biomacromolecules identified through their chem. formulas

-carbs: Have C,H,O in a common ratio according to formula (CH2O)n -Protein: May contain Sulphur (some include it) -Nucleic Acids: Will contain phosphorus in relatively large amounts (contain phosphate groups)

Endosymbiosis and how to the evolution of eukaryotic cells

-cells which lives inside another cell with mutual benefits -Eukaryotes are believed to have evolved from early prokaryotes that were engulfed by phagocytosis -The engulfed cell remained undigested as it contributed new functionality to the engulfing cell -Over generations, the engulfed cell lost its independence utility and became a supplement organelle

Challenges to cell theory: Giant algae

-certain species may grow large -challenges idea cells are microscopic and larger organisms are composed of many

What are the conditions needed for non-living synthesis of organic matter (and potential location)

-conditions: reducing atmosphere (no o2), high temps (>100degreesC), or electrical discharge -Location: Volcano, hydrothermal vent, or meteor

principles of vaccination

-contain attenuated forms of a pathogen that cannot cause disease -vaccinations induse active immunity by stimulating production of memory cells -When exposed to actual pathogen. the memory cell is triggered faster/stronger secondary immune resources

cortical reaction

-cortical granules release enzyme that destroy sperm-binding proteins on the jelly coat (after fertilization) -Prevents other sperm from penetrating the fertilized egg (polyspermy)

birds (vertebrate)

-covered in feathers (made of keratin) -have internal fertilization (lay hard eggs) -Breathe via lungs (with parabronchial tubes) -are endothermic

Fish (vertebrate)

-covered in scales (bony plate of skin) -Reproduce via external fertilization -breathe through gills -Are ectothermic

reptiles

-covered in scales (made of keratin) -have internal fertilization (lay soft eggs) -breathe via lungs (with extensive folding) -are ectothermic

mammals (vertebrate)

-covered in skin (with keratin hair follicles) -internal fertilization (and mammary glands) -breathe via lungs (with alveoli) -Are endothermic

Pulmonary circulation

-deoxygenated blood returns from the body (via vena cava) to the RIGHT side of the heart -It is pumped (by right atrium/right ventricle) to the lungs via the pulmonary artery

Role of positive feedback in the menstrual cycle

-during ovulation, estrogen stimulates LH / FSH production (leading to a surge) -this is an example of this type of feedback as the response (estrogen production) promotes the stimulus (FSH / LH production)--this feedback will cease when the follicle ruptures (ovulation)

how can organisms be cloned artificially?

-embryonic cells retain pluripotency, and by dividing the embryo into two cell masses, and each can grow into a new organism. Because these cells have identical genetic information, they will form clones -Nucleus removed from diploid body cell of an adult, egg is enucleated via uv radiation, and diploid nucleus is inserted into enucleated egg. Egg stimulated to divide by electric shock, and as a result, all DNA comes from diploid nucleus, and resulting embryo will be a clone of the adult.

Three domains of life

-eukarya (all eukaryotic organisms) -Archaea (prokaryotic extremophiles) -Eubacteria (common pathogenic bacteria)

Speciation

-evolutionary process that results in the formation of new species from pre-existing species -occurs when reproductive isolating mechanisms prevent two organisms from producing fertile offspring

Vascular bundle

-exists centrally between both layers (allowing equal access) -contains xylem for water to leaf transport and phloem for food transport from leaf remember it as the big red blocky circle

Challenges to cell theory: aseptate fungal hyphae

-filamentous hyphae that are not partitioned will have continues cytoplasm -Challenges idea living structures are composed of discrete cells

difference between genophore and plasmid

-genosphere: circular DNA molecule that contains genetic material -Plasmids are additional autonomous DNA molecules that can be transferred via bacterial conjugation

linkage groups

-group of genes whose loci are on the same chromosome -Function as a single inheritable unit and do not follow independent assortment (aren't likely to be inherited together during crossing over; other times they are) -RIP Mendel :(

amphibian (vertebrate)

-have moist skin, permeable to gases -reproduce via external fertilization -breathe via skin (may have simple lungs) -are ectothermic

How is the structure of the arteries related to its function

-have thick walls and narrow lumens because they transport blood at high pressure -Have muscular/elastic walls to stretch with pulse flow

How is the structure of the veins related to its function

-have thin walls with wide lumens and valves because they transport blood at low pressure -have valves to prevent backflow

coniferophyta

-have vascularization -have seeds (found in cones) -leaves narrow with a thick, waxy cuticle Think: literally has 'cone' in it

angiospermophyta

-have vascularization -have seeds in fruits -have flowers as reproductive organs Think: flowers in these, which hold pollen (plant sperm), which sperm is in the name

Filincinophyta

-have vascularization -spores in sporandia on underside of leaf -have large fronds divided into leaves Think: filin sounds kinda like fern

the electrical events that trigger the contraction of the heart muscle fibers

-heart beat is myogenic--means cardiac contraction is initiated by the heart -electrical signals are initiated by the sinoatrial (SA) node (the peacemaker) -It stimulates the atria to contract and also relays signals to an atrioventricular node -the atrioventricular node sends signals via the Bundle of His to Purkinje fibers -These fibers innervate the ventricles and cause them to contract

How are pentadactyl limbs of vertebrates providing evidence of evolution

-homologous structures are anatomical features that share a common underlying structure despite having distinct functions--the pentadactyl limb of mammals is an example of a homologous structure -The rapid diversification of the anatomical feature is the result of adaptive radiation -Closely related species will have more similarities in their homologous structures

three types of immune-system disorders

-hypersensitivity disorders (allergies) -autoimmune disorders (multiple sclerosis, lupus) -Immunodeficiency disorders (HIV/AIDS)

How do abiotic factors affect rate of transpiration in a typical terrestrial plant: light

-increasing light intensity to which a plant is exposed increases the rate of transpiration -increasing light exposure causes more stomata to open to facilitate photosynthetic gas exchange

How do abiotic factors affect rate of transpiration in a typical terrestrial plant: humidity

-increasing the humidity is predicted to cause a decrease in the rate of transpiration -less vapor will diffuse from the leaf if there is more vapor in the air

How do abiotic factors affect rate of transpiration in a typical terrestrial plant: wind

-increasing the level of wind exposure causes an increase in the rate of transpiration -Wind/air circulation removes water vapor from near the leaf, effectively reducing proximal humidity

structure of the xylem

-inner lining is composed of dead cells that have fused into a continues tube -these cells lack a membrane, allowing water to enter the xylem freely -the cell walls have thickened cellulose and are reinforced with lignin (annular or spiral) -The outer layer is perforated (has pores), enabling water movement out of the xylem

process of spermatogenesis

-involves mitosis followed by cell growth followed by meiosis (two divisions) and differentiation -Occurs in seminiferous tubules (testes) and produces four gametes per germ cell -Gametes differentiate into spermatozoa via a process that occurs continuously from puberty

selective reabsorption

-located in the convoluted tubules (mainly proximal but sometimes distal) -involves the reuptake of usable substances from filtrate -substances are actively transported across apical membrane before diffusing across basolateral membrane -Tubules are lined by microvilli (increased SA) and reabsorb the following materials: glucose and amino acids (symport with Na+), ions and vitamins (via protein pumps), water (follows via osmosis)

Homologous structures

-look different -because of selective pressures -organisms share common ancestry -arise via divergent evolution example: pentadactyl limb in vertebrates

analogous structures

-look similar -because of common selective pressures -organisms do not share a common ancestry -arise via convergent evolution -example: fins on dolphins and sharks

consequences of lung cancer

-lungs are vital to normal body function and thus the abrogation of their function is detrimental to health -abnormal growth can impact normal tissue function, with symptoms varying according to size and location -Lungs possess a rich blood supply, increasing the likelihood of the cancer spreading (metatosis)

Suggest ways of measuring enzyme-catalyzed reactions: conversion of hydrogen peroxide to oxygen gas by catalase:

-measure time taken for an enzyme-soaked disc to rise in solution. -Measure gas formation via pressure change (w/ data logger) or displacement of a syringe cap

Type I pneumocyte

-mediate gas exchange with capillaries -are long and thin (lower diffusion distance) -compromise most of the alveolar surface

different mutations

-missense mutations are when a mutation in RNA happens, and it causes a change in the sequence -A silent mutation is when a mutation in the RNA occurs, but no change happens -Nonsense mutations create a STOP codon, which prematurely ends the polypeptide chain

discrete and continuous variation

-monogenic traits have a finite pattern of expression (i.e. discrete variation) -Polygenic traits normally exhibit a bell-shaped distribution (i.e. continuous variations)

Phloem purpose

-moves materials via active translocation -transports nutrients bidirectionally -phloem occupy the outer portion of a vascular bundle -vessel wall made of cells connected by sieve plates -vessels are composed of living tissue

advantages of mitochondrial DNA as a phylogenetic tool

-mtDNA is commonly used for comparing species that are closely related -It is inherited maternally (more direct lineage) -It lacks recombination (as mtDNA is circular) -Has a relatively stable (and high) mutation rate

bryophyta

-no 'true' leaves, roots, nor stems -no vascularization (no xylem/phloem) -spores in capsule at the end of stalk think: moss

things the blood plasma transports

-nutrients -antibodies -CO2 -hormones -O2 -Urea -Heat

ultrafiltration

-occurs in glomerulus / bowman's capsule -Non-specific filtration of blood under high pressure (separates blood cells and proteins) -Glomerular capillaries are fenestrated and the capsule is lined with podocytes that have extensions -Blood freely enters the capsule by passing between the extensions, so the only barrier is a basement membrane -Blood enters the glomerulus via a wide afferent arteriole and exits via a narrow efferent arteriole -This makes it difficult for blood to exit the glomerulus, increasing the hydrostatic pressure in the glomerulus

process of oogenisis

-occurs in ovaries (completed in oviduct), with only one gamete produced per germ cell -There is unequal division of cytoplasm (forms one egg and up to three polar bodies) -Occurs in staggered stages (fetal development -> puberty -> fertilization)

Behavioral reproductive isolation

-occurs when two populations exhibit different specific courtship patterns Ex: certain populations of crickets may be morphologically identical but only respond to specific mating calls

Geographic reproductive isolation

-occurs when two populations occupy different habitats or separate niches within a common region Ex: lion and tigers occupy different habitats and do not interbreed (usually)

Spongy mesophyll

-on the lower surface of the leaf, the cells are interspersed by space and near stomata -this increases gas exchange for photosynthesis Remember S is on bottom

location of the palisade mesophyll

-on the upper surface of the leaf, the cells are packed tight and rich in chloroplasts -This increases light absorption for photosynthesis Remember P as top

how does flowering occur in short-day plants and long-day plants

-phytochrome exists in two forms: an inactive form (Pr) is predominant at night, while an active form (Pfr) is predominant during day (the active form triggers flowering and requires a critical night length) -In long-day plants, Pfr activates flowering so flowering is induced when night is short (upped Pfr) -In short-day plants, Pfr inhibits flowering so flowering is induced when night is long (lower Pfr)

How can photosynthetic pigments be separated through chromatography

-pigments are dissolved in a fluid (mobile phase) -fluid is then passed through a static material (stationary phase) -Different pigments pass through the static material at different speeds, becoming separated -A retardation factor (Rf) can be assigned to each pigment, which allows for identification

process of active translocation

-plants transport organic molecules from source (photosynthetic tissue) to sink (storage organs) -these organic molecules are transported via a tube system called the phloem in a viscous fluid called sap -organic molecules are are loaded / unloaded via companion cells (either by a symplastic or apoplastic pathway) -active loading of solutes into phloem creates high concentration that draw water (from xylem) via osmosis -Incompressibility of water causes the sap volume/pressure to increase resulting in mass flow -Organic molecules are actively unloaded at the sink which causes water to return to the xylem

porifera (invertebrate)

-possess an asymmetrical body plan -having no mouth or anus (have pores) -May have structural support ex: sea sponge

platyhelmintha (invertebrate)

-possess bilateral symmetry -Have mouth but no anus (single opening) -Flattened body increass SA:Vol ratio Ex: flatworm

annelida (invertebrate)

-possess bilateral symmetry -have separate mouth and anus -body composed of rings segments Ex: worms

Mollusca (invertebrate)

-possess bilateral symmetry -have a separate mouth and anus -may have shell ex: octopus

Anthropoda (invertebrate)

-possess bilateral symmetry -have a separate mouth and anus -have jointed appendages and exoskeleton ex: scorpions

how can potometers be used to measure transpiration rates

-potometers estimate transpiration rate by measuring the rate of water loss or uptake by a plant -they record the distance moved by an air bubble or meniscus to indicate the rate of water uptake

oxidative phosphorylation in terms of chemiosmosis

-protons build up in the intermembrane space, creating a gradient -the protons can only return to the matrix via a transmembrane enzyme called ATP synthase -The movement of protons through this enzyme triggers the formation of ATP (from ADP and Pi) -Because the proton gradient was created by the oxidation of NADH, this form of ATP production is called oxidative phosphorylation

Indirect active transport

-protons pump expel H+ ions into the soil, displacing the cationic minerals from clay -Displaced minerals will passively diffuse into the root (along a concentration gradient) -Anionic minerals may bind to the H+ ions and be reabsorbed with the proton

process of the link reaction

-pyruvate is transported from the cytosol into the mitochondrial matrix -Pyruvate is decarboxylated and oxidized (CO3 and NADH is produced) -It is then converted to an acetyl compound and attached to coenzyme A to form acetyl CoA (2C)

impact of competitive inhibitors on reaction rate GRAPH

-reactions are slowed -Maximal rate sill achievable (but needs higher substrate concentration)

Structure of ribosomes

-ribosomes are composed of a large and a small subunit (made of protein and rRNA) -The small subunit binds to mRNA -the large subunit contains three tRNA binding sites (E, P, and A)

Concept of the 'molecular clock' as a means of dating evolutionary relationships

-some genes or protein sequences may accumulate mutations at a constant rate (i.e. molecular clock) -The time of divergence can be calculated based on the total number of mutations -different genes may change at different rates and rate of change may differ between species -over long periods, earlier changes may be reversed by later changed (confounding accuracy of predictions)

relationship between CO2 levels and temp

-strong positive correlation between CO2 levels and global temps -there have been fluctuating cycles that can be attributed to global warm ages and ice ages -CO2 levels are the highest ever recorded (however CO2 increases may not always precede temp increases)

The role regulatory proteins play in moderating gene expression levels

-the binding of RNA polymerase to the promoter can be controlled by regulatory proteins -activators bind to enhancer sequences and make it easier for the enzyme to bind (increasing expression) -Receptors bind to silencer sequences and make it harder for the enzyme to bind (decreases expression)

action potential

-the charge difference across a membrane when the neuron is firing (~30 mV) -involves depolarization and repolarization

resting potential

-the charge difference across a membrane when the neuron is not firing (~70 mV) -Maintained by the sodium-potassium pump

Evolution

-the cumulative change in the heritable characteristics of a population -a change in the allele frequency of a gene pool across successive generations

Adaptive radiation

-the rapid evolutionary diversification of a single ancestral line (ex: variety of beak size in Darwin's finches) -It occurs when members of a species occupy a variety of niches with different environmental selective pressures

how does natural selection lead to evolution

-there is genetic variation within a given population (which can be inherited) -There is competition for survival because of overproduction of offspring -environmental selection pressures lead to differential reproduction -organisms with beneficial adaptations are better suited for survival and more likely to reproduce and pass on genes -Over generations, there is a change in the allele frequency within a population (evolution)

Acrosome reaction

-to enter the egg, sperm must penetrate the protective jelly coat (zona pellucida) -Acrosome vesicles release enzymes which soften the glycoprotein matrix -Egg and sperm membranes fuse and the sperm nucleus (+ centriole) enter the egg

role of histamine in the allergic response

-when a B cell encounters the allergen, it differentiates into plasma cells and makes specific antibodies (IgE) -The IgE antibodies attach to mast cells, effectively 'priming' them towards the allergen -upon re-exposure, the IgE-primed mast cells release large amounts of histomine which causes inflammation

role of hCG in early pregnancy

-when a blastocyst is implanted into the endometrium it begins to secrete hCG (human chorionic ganadotropin) -hCG sustains the corpus luteum and prevents its degeneration (continues to make estrogen and progesterone) -Estrogen inhibits FSH and LH, preventing further egg release, while progesterone maintains the endometrium -When a placenta develops and begins to produce progesterone, hCG levels drop and he corpus luteum degenerates

three different types of chemical energy

1. ATP: an immediate energy source used by cells to fuel biological processes 2. hydrogen / electron carriers (e.g. NADH): an intermediate / transitional energy form 3. Organic molecules: stored energy (e.g. carbohydrates and triglycerides)

four conditions under homeostatic regulation

1. Body temp. (thermoregulation) 2. Blood glucose concentration 3. CO2 levels and blood pH 4. Water balance (osmoregulation)

simple dichotomous key to identify five vertebrate classes

1. Does it have hair / fur (NO: go to 2, YES: Mammal) 2. Does it have feathers? (NO: go to 3, YES: bird) 3. Does it have internal fertilization? (NO: go to 4, YES: reptile) 4: does it have gills as an adult (NO: amphibian, YES: fish)

three aspects of the smallpox virus that allowed for a successful vaccination campaign

1. Easily identifiable 2. Infection period short and virus was stable (not mutating) 3. Transmission required direct contact and there were no animal vectors or reservoirs to sustain the virus

Steps in enzymatic binding and catalytic activity

1. Enzyme and substrate collide in an appropriate orientation (substrate binds to the enzyme's active site) 2. Enzyme and substrate form a complex, leading to catalysis (enzyme-substrate interaction shows specifically) 3. Substrate is converted into a product (enzyme may stress the bonds within the substrate to catalyze this process) 4. Enzyme and product dissociate (enzyme is not consumed by the reaction and may be re-used)

examples of polygenic inheritance

1. Human height 2. Skin color / pigmentation

Three examples of post-transcriptional modifications

1. Methyl cap added to the 5'-end (protects against degradation and allows recognition by ribosome) 2. polyadenylation occurs at the 3'-end (improves stability and facilitates nuclear exports) 3. Splicing occurs (introns are removed)

Three types of mutagens

1. Physical (ex: radiation) 2. Chemical (ex: tobacco and other carcinogens) 3. Biological (certain viruses)

Four main components of blood

1. Plasma 2. Red blood cells (erythrocytes) 3. White blood cells (leukocytes) 4. Platelets (thrombocytes)

diagram of ovarian tissue

1. Primordial follicle 2. Primary follicle 3. secondary follicle 4. Graafian follicle (mature) 5. oocyte 6. corpus luteum 7. corpus albicans

How does a nerve impulse pass along a non-myelinated neuron

1. Sodium-potassium pump maintains a resting potential -It expels 3 sodium per 2 potassium admitted (active transport) -This results in a negative membrane potential (roughly ~70mV) 2. Sodium channels open in response to signal at receptor / dendrite. -There is a passive influx of sodium ions to cause depolarization 3. Potassium channels open in response to depolarization -There is a passive efflux of potassium ions (repolarization) 4. The neuron needs a length of time needed before it can re-fire again -During this refractory period, the resting potential is re-established by the NA+/K+ pump

Key events of the menstrual cycle

1. follicular phase: -FSH stimulates growth of several follicles, the dominant follicle secretes estrogen which stops the growth of other follicles (lower FSH) and also stimulates endometrial development 2. Ovulation -A surge in LH causes ovulation (egg release) and the rupturing of the follicle creates a corpus luteum 3. Luteal phase -Corpus luteum makes estrogen / progesterone, which stimulates endometrial growth and inhibits FSH / LH -Corpus luteum degrades over time, so estrogen / progesterone levels drop and endometrium is sloughed away

four stages of aerobic respiration

1. glycolysis (cytosol) 2. link reaction (from cytosol to matrix) 3. Kreb cycle (matrix) 4. electron transport chain (inner mitochondrial membrane)

examples of when molecular evidence was used to reclassify existing schemes

1. species of the figwort family have been reclassified based on chloroplast DNA 2. the homininae sub-family was created to group gorillas and humans together

process of micropropagation and provide three examples of potential applications

1. tissue sample (explant) grown in nutrient agar 2. Development prompted by growth hormones 3. Growing shoots divided (multiplication phase) 4. Cloned plants transferred to new soil -------------------------------------------------------------- 1. rapid bulking: cloning desirable stock plants 2. virus-free strains: cloning non-infection tissue 3. Propagation of rare species: prevents extinction

nucleotide structure

5 carbon sugar, phosphate group, nitrogenous base

Chemical equation for the process of photosynthesis

6CO2 + 12H20 + sunlight = C6H12O6 + 6O2 + 6H20

Photosynthesis equation

6CO2 + 6H2O ------> C6H12O6 + 6O2

Substrate

A compound that binds to an enzyme's active site and is converted into a product (the substrate is complementary in shape and chemical properties to the active site)

enzyme

A globular protein that speeds up the rate of a chemical reaction by lower the activation energy (biological catalyst)

Species

A group of organisms that can potentially interbreed to produce fertile viable offspring

community

A group of populations living together and interacting with each other within a given area

Denurturation

A loss of protein structure resulting in loss of biological activity

Law of limiting factors

A reaction will only proceed as fast as the component nearest its minimum value (rate-limiting factor)

Monomer

A recurring subunit within a more complex polymer

Gene

A section of DNA that codes for a particular characteristic (via production of specific proteins)

define prokaryote

A simple cell that lacks a nucleus and all membrane-bound organelles, ex: bacteria

Recombinants of a cross that's (AB/ab) x (ab/ab)

Ab/ab AND aB/ab

Sites on a tRNA molecule and their function

Acceptor stem - Carries the amino acid T arm - associated with the ribosome (via E, P, A sites) Anticodon - associates with mRNA (via complementary codon) D arm - associates with tRNA--activating enzyme

the conclusions drawn from william harvey's investigation into sexual reproduction of deer: after Harvey

According to Harvey: menstrual blood does not contribute to the development of the fetus, but he was unable to detect the correct mechanism (viable light microscopes had not yet been invented)

the conclusions drawn from william harvey's investigation into sexual reproduction of deer: BEFORE Harvey

According to the soil and seed theory: a male "seed" mixes with the menstrual blood "soil" to form an egg that develops in a fetus

Action spectrum and absorption spectrum

Action: The range of wavelengths used by a plant for photosynthesis (red and blue is used for high photosynthetic rate, but green is not) Absorption spectrum:The range of wavelengths absorbed by a plant (each pigment has its own spectrum). For chlorophyll, red and blue are absorbed, but green is reflected.

induced fit model

Active site is not a perfect fit, but undergoes a confrontational change in shape to accommodate substrate. This stresses bonds in the substrate and gives rise to broad specificity.

determining size of an image

Actual size = Image size/magnification magnification is usually on the image

two key properties of the adaptive immune system

Adaptive: it can differentiate between pathogens and target a response that is specific to a given pathogen memory: it can respond rapidly upon re-exposure to a specific pathogen, preventing disease symptoms

Heterozygous

Alleles are different for a given characteristic

Homozygous

Alleles are the same for a given characteristic

What waste products do fish produce

Ammonia (very toxic but very water soluble)

Allele

An alternate form of a gene

Mesocosm

An enclosed environment that allows a small part of the natural environment to be viewed under controlled conditions

Convergent evolution

Ancestral relatedness: species do NOT share a common ancestry Evolutionary effect: adopt similar phenotypic features because of shared selection pressures type of adaptation: analogous structures

Cytokinesis in plants versus animals

Animals: Microtubules filaments form a ring around the cell center which then contracts. separation is centripetal because it starts at the outside and moves in. Plants: Vesicles form in a row at the center of the cell (equatorial plane) which fuse to form an end plate. Separation is centrifugal because it starts in the center and then moves out.

system of antigenic presentation on human red blood cells (i.e. the ABO blood system)

Antigen on blood cell: Type A: A antigen Type B: B antigen Type AB: both A and B antigen Type O: No antigen Antibodies in bloodstream: Type A: anti-B antibody Type B: anti-A antibody Type AB: no antibodies Type O: Anti-A and Anti-B antibodies Blood donors: Type A: can take A or O, but not B or AB Type B: can take B or O, but not A or AB Type AB: Can take any (universal acceptor) Type O: Can only take O (universal donor)

Antigen v antibody

Antigen: substance that the body recognizes as foreign and that will elicit an immune response Antibody: proteins produced by lymphocytes that recognize and neutralize specific antigens

Two arguments against human-induced climate change and counterpoints to each

Argument 1: Solar activity has caused the current climate change -There is no evidence of an increased number of sunspots Argument 2: Current climate changes reflect a natural climatic cycle -Changes do not usually occur as abruptly and past abrupt changes were always destructive to life

temperature on enzyme activity

At low temps, there is insufficient activation energy for reaction to proceed. -As temp. increases, the rate of reaction increases. -At a certain temp. the enzyme peaks. -After that, the enzyme denatures

Benefits and risks associated with the use of genetically modified crops

Benefits: improve yields. Potentially long shelf life. reduces need for chemical pesticides. Allows growth in wider areas (ex: salty soils) Risks: Risks of cross contamination (ex: super weeds). Threatens native biodiversity. Difficult to police internationally. parenting could lead to monopolies

Arteries

Blood speed: fast Blood pressure: high Size of lumen: narrow Valves: no Wall composition: Thick walls with large amounts of muscle and elastic fibers Function: carry blood from heart

Capillaries

Blood speed: low Blood pressure: low Size: extremely narrow Valves: no Wall composition: extremely thin wall composed of single layer epithelium Function: gas/material exchange

Veins

Blood speed: slow Blood pressure: low Size of lumen: wide valves: yes Wall composition: thin walls with small amounts of muscles and elastic fibers Function: carry blood to heart

Cell respiration equation

C6H12O6 + 6O2 ------> 6CO2 + H2O + energy

Chemical formula for an unsaturated fatty acid

CH3 - (CH2)n - COOH

four greenhouse gases

CO2, Methane, nitrogen oxides, fluorinated gases (e.g. CFCs)

Occlusions to the coronary arteries

Causes: Atherosclerosis can be caused by age, hypertension, obesity, diseases (ex: diabetes), smoking, genetics, diet, and lack of exercise Consequences: coronary heart disease occurs when coronary arteries become narrower. Coronary arteries oxygenate heart tissue so their occlusion results in myocardial infarctions (heart attack)

health consequences of Hiroshima and Chernobyl

Chernobyl: released more fissionable material with longer half lives Hiroshima: Bomb was detonated above ground and radiation was dispersed Therefore, chernobyl responsible for more severe long-term health effects (ex: cancer)

Main photosynthetic pigment in plants and where it is found

Chlorophyll is the main pigment, and is found in chloroplast in plants

prophase II

Chromosomes condense, nuclear membranes dissolves, centrosomes move to opposite poles (perpendicular to before)

Telophase II

Chromosomes condense, nuclear membranes reform, cells divide (cytokinesis) to form four haploid daughter cells

Telophase I

Chromosomes decondense, nuclear membranes may reform, cell divides (cytokinesis) to form two haploid daughter cells

Three human activities that trigger carbon fluxes

Combustion of fossil fuels deforestation agricultural practices (produces methane gases)

xerophyte

Conditions: arid/dry and high temps Issues: increased water loss via evaporation. Reduced water uptake via roots Adaptation: reduced leaves (lowers evaporation). Thick cuticles (prevent water loss). Stomata in pit (traps water vapor). CAM physiology (open stomata at night)

Clade

Consists of a single common ancestor and all the descendants of that ancestor

Identify the properties of a phospholipid

Consists of: -Phosphate head (hydrophilic = water loving) -2x Fatty Acid (hydrophobic = hates water) -The phosphate group is connected to the fatty acid tails via a glycerol group

relationship between the structure of the chloroplast and its function: stroma

Contains appropriate enzymes and suitable pH for the calvin cycle to occur

How does crossing over give rise to infinite genetic variety?

Crossing over involves the exchange of genetic material between non-sister chromatids of a bivalent -Bivalents are connected at points called chiasma during the process of synapsis (during prophase I) It is at these chiasma that recombination occurs

cyclic and non-cyclic photophosphorylation

Cyclic photophosphorylation: Photosystems: PSI only Products: ATP only Purpose: cannot be used to make organic molecules --------------------------------------- non-cyclic photophosphorylation: Photosystems: PSI and PSII Products: ATP and NADPH Purpose: Used to make organic molecules via light independent reaction (calvin cycle)

five mechanisms of disease transmission

Direct contact: transfer of pathogens via physical association Exchange of body fluids: from blood transfusions or sexual intercourse ( ͡° ͜ʖ ͡°) Contamination: infestations of pathogens growing on, or in, edible food sources Airborne: certain pathogens can be transferred in the air via coughing and sneezing Vectors: intermediary organisms that transfer pathogens without developing symptoms themselves Acronym: Driven Elves construct automated vans

relationship between the structure of the chloroplast and its function: thylakoid

Disc shaped with small lumen (small volume maximizes proton gradient)

factor that determines the likelihood of recombination between two linked groups

Distance: further apart two genes on a chromosome, the more likely they are to recombinate

Disruptive selection

Effect: where both phenotypic extremes are favored at the expense of the intermediate phenotypes Example: pigmentation of peppered moth (dark or light coloration for camouflage)

directional slelection

Effect: where one phenotypic extreme is selected at the cost of the other phenotypic extreme Example: antibiotic resistance in bacteria (presence of antibiotic = resistance up)

implications of stem cell therapy using cells derived from different sources

Embryo: Growth potential is high, tumor risk is high, can be generated artificially by SCNT, and requires the destruction of an embryo Cord blood: growth potential is high, tumor risk is lower than embryo, its easily obtained and stored, but cells must be stored from birth at high cost Adult tissue: Growth potential is low, tumor risk is lowest, difficult to obtain, invasive to extract, and may be limited in scope of application

Emergent properties of cells

Emergent properties are functions present in multicellular organisms that are not present in any of the individual component cells. Emergent properties arise from the interaction of individual cells to produce new functions in multicellular aggregates. An example is increased antibiotic resistance seen in biofilms

How do enzymes catalyze chemical reactions

Enzymes speed up the rate of a chemical reaction by lowering the activation energy threshold

how does compartmentalization of eukaryotic cells allow for greater complexity

Eukaryotic cells contain sub-cellular structures called organelles, which compartments perform specialized functions that provide eukaryotic cells with a greater level of functional complexity

Discuss evidence for and against health risks associated with diets rich in lipids

Evidence for: A positive correlation exists between intake of saturated fats and incidence of CHD. Intervention studies demonstrate that lowering intake of saturated fats reduce onset of CHD. In patients that have died from CHD, fatty deposits with high levels of trans fats were found in arteries. Evidence against: Certain populations have high fat intakes but low rates of CHD (eg: maasai tribe in africa). Genetic factors play significant role. Cohort size and comparison and study duration influence results from intervention studies

How does alternative splicing increase the number of different proteins an organism can produce

Exons can be selectively removed via alternative splicing to produce different protein variants from the same gene--this increases the number of proteins an organism can produce relative to the number of genes

Food chain v food web

Food chain: linear feeding relationship between species in a community Food web: multiple food chains all in one place

Three primary sources of genetic variation

Gene mutations Meiosis (crossing over and independent assortment) Sexual reproduction (random fusion of sperm and egg)

active transport in the digestive system

Glucose and amino acids are co-transported with Na+ ions

Location of key events in aerobic respiration

Glycolysis: -oxidation = 2 NADH -ATP formation = NET 2 ATP (substrate level, 2 lost to start it) Link reaction: -Decarboxylation = 2 x CO2 -Oxidation = 2 NADH Krebs cycle: -Decarboxylation = 4 x CO2 -Oxidation = 6 NADH AND 2 FADH2 -ATP formation = 2 ATP (substrate level) Electron transport chain: -ATP formation = 32 ATP (oxidative phosphorylation) Total: -Decarboxylation = 6 CO2 - Net ATP formation = 36 ATP (38 total, 2 lost in glycolysis)

Why is an intestine cell shaped like it is?

Has microvilli to increase SA (allows for more material absorption)

Components of DNA replication

Helicase: unwinds and separates double stranded DNA (breaks H bonds between the base pairs) DNA Gyrase: Relieves torsional strain created by helicase action (i.e. prevents supercoiling) SSB Protein: Prevents DNA strands from re-annealing (SSB proteins will be displaced by DNA pol III) DNA primase: Lays down a short RNA primer to provide an initiation point for polymerization (DNA Pol III can only add nucleotides to the 3'-end of an existing nucleotide chain) DNA Pol III: Extends the nucleotide chain from the primer (dNTP's align opposite complementary bases and DNA pol III covalently joins them together) DNA Pol I: Removes and replaces RNA primers with DNA nucleotides DNA Ligase: covalently joins Okazaki fragments together (on lagging strand)

Where does DNA replication happen

In the nucleus during S phase

Consumer

Ingest organic molecules from living or recently killed organisms

relationship between the structure of the mitochondrion and its function

Inner membrane: highly folded (increases SA:Vol ratio so more oxidative phosphorylation occurs) Matrix: Has appropriate enzymes and suitable pH for the Kreb cycle to occur Outer membrane: Has appropriate carrier proteins for shuttling pyruvate into mitochondria Intermembrane space: small volumes (maximizes proton gradient with the accumulation of hydrogen ions)

Stages of the cell cycle

Interphase, M phase, G0 (Gap), G1 (growth), S phase (DNA replication), G2 (Growth/proofreading), mitosis (nuclear division), Cytokinesis (cytoplasmic division)

Seven levels of hierarchy of taxa

Kingdom, phylum, class, order, family, genus, species Acronym: Katy Perry Comes Over For Gay Sex

Fragments

Larger fragments move more slowly though gel matrices and hence do not travel as far

advantages and disadvantages of light and electron microscopes

Light: Can view living specimens and natural colors, but lower magnification and lower resolutions Electron: higher magnification and resolution, but can only view dead specimen and view is monochrome--false color

Scientists that contributed to the elucidation of DNA structure

Linus Pauling: Identified molecular distances and bond angles for basic molecular structures Phoebus Levene: Identified structure of nucleotide (sugar & phosphate base) Erwin Chargaff: Determined that there is an equal number of purines and pyrimidines Rosalind Franklin: Identified the organization of DNA into helical structures

High density v low density lipoproteins

Low density (LDLs): transport cholesterol from the liver to the rest of the body High density (HDLs): Scavenge excess cholesterol and return it to the liver for disposal

Class I and class II MHC proteins

MHC I: where found: all nucleated body cells (not RBCs) Antigens presented: endogenous antigens cells presented to: cytotoxin T cells (and TH cells) MHC II: Where found: antigen-presenting cells (ex: macrophages, B cells) Antigens presented: exogenous antigens Cells presented to: B cells (and TH cells)

Why are X-linked disorders more common in males?

Males only have one X chromosome and so cannot be carriers for recessive conditions

excretory system of insects and mammals

Mammals possess autonomous kidneys insects possess Malpighian tubules that are connected to the insect's digestive system

Conditions which photosynthesis can be detected and how they can be measured: CO2 production

Measure by a change in pH if plant is in solution (CO2 dissolves in water to form carbonic acid--that decreases pH)

Conditions which photosynthesis can be detected and how they can be measured: change in biomass

Measure by a change in weight (plant sample must first be desiccated to account for change in mass because of water)

Conditions which photosynthesis can be detected and how they can be measured: oxygen uptake

Measure by pressure change (data logger) or displacement of syringe cap

Meiosis v mitosis

Meiosis: -Type of cells: sex cells( ͡° ͜ʖ ͡°) Number produced: 4 number of divisions: 2 Ploidy of daughter cells: haploid Genetics of daughter cells: shows genetic variations Mitosis: -Type of cell produced: body (somatic) cells -Number produced: 2 -Number of divisions: 1 -Ploidy of daughter cells: diploid -Genetics of daughter cells: Are genetically identical

role of the ER (Endoplasmic reticulum)

Membrane network that transports materials between organelles via vesicles

Key components of translation

Messenger RNA - contains the genetic instructions Ribosome - site of translation Codon - triplet bases denoting a specific amino acid Anticodon - complementary sequence on tRNA molecule Transfer RNA - transfers amino acids to ribosome Amino acid - monomeric component of a polypeptide chain Peptide band - the covalent bond formed between amino acids Polypeptide - the end product of translation Acronym: MR CAT APP

Functions of life

Metabolism: living things undertake essential chemical reactions Reproduction: Living things produce offspring Sensitivity: living things are responsive to stimuli Homeostasis: living things maintain a stable internal environment Excretion: living things require the removal of waste products Nutrition: living things exchange materials with their environment Growth: living things can move and change shape or size Acronym: MR SHENG

Methodology and conclusions drawn from Mendel's pea plant experiment

Method: Mendel crossed pure breeding pea plants (P generation), then crossed large numbers of the off spring (F1). He did this for a variety of different characteristics (ex: flower color, plant height, etc) Conclusion: Mendel concluded that organisms have discrete factors that control inheritance of traits (genes). There are different versions of these factors (alleles) and each parents passes on one copy to offspring. Only one version gets expressed (dominance/recessiveness)

Difference between monocot stem and dicot stem

Monocot: less centered, with dots all over the place Dicot: ringed, and has half circles on them

Protein

Monomer: Amino acid Polymer: polypeptide Bond involved: peptide band

Cellulose

Monomer: B-glucose Bonding: 1-4 linkages -Shape: Linear (sheets) -Function: structural components of plant cell walls

Lipid

Monomer: Glycerol + fatty acids (x3) Polymer: Triglyceride Bond involved: Ester linkage

Carbohydrates

Monomer: Monosaccharide Polymer: polysaccharide Bond involved: Glyosidic linkage

Nucleic acid

Monomer: Nucleotide Polymer: DNA or RNA Bond involved: Phosphodiester bond

Amylose

Monomer: a-glucose Bonding: 1-4 linkages Shape: linear (helical) -short term energy storage in plants (type of starch)

Amylopectin

Monomer: a-glucose Bonding: 1-4 linkages AND 1-6 linkages Shape: less branched (~20 per units) Function: Short-term energy storage in plants (type of starch)

Glycogen

Monomer: a-glucose Bonding: 1-4 linkages AND 1-6 linkages Shape: more branched (~per 10 units) Functions: Short-term energy storage in ANIMAL cells

Three examples of monosaccharides, disaccharides and polysaccharides

Monosaccharides: Glucose, Glactose, Fructose (good flavor :) Disaccharides: Lactose, sucrose, Maltose (length supports movement) Polysaccharides: Cellulose, Glycogen, starch (hint: can be stored)

how do neonicotinoid pesticides affect acetylcholine transmission

Neonicotinoid pesticides bind irreversibly to acetylcholine receptors in insects -AChE cannot break down neonicotinoids--this causes fatal overstimulation of receptors

Abiotic factors

Non-living chemical and physical factors in an environment (which affects ecosystem)

Diploids

Nuclei passes pairs of homologous chromosomes (ex: body cells = 2n)

Parts of the plant cell

Nucleus is the large circle Nucleolus is the smaller circle chloroplast are the things with a lot of circles in them The central vacuole is he large space with nothing in it the cell wall is the wall of the cell mitochondrion are the place near the chloroplasts where the dark reaction happens

heterotrophs

Obtain their organic molecules form other organisms

Complete dominance

One allele (dominant) masks expression of other allele (recessive) in heterozygotes

Type I diabetes

Onset: childhood (early onset) effects: body doesn't produce insulin Cause: Beta cells destroyed (maybe autoimmune) Treatment: insulin injection

Electrons

Oxidation: loss Reduction: Gain

Metabolic functions of paramecium and chlorella

Paramecium: Heterotrophic for nutrition, engulfs food and absorbs gases through absorption, and solids are removed through anal pore, liquids through vacuole Chlorella: autotrophic, contains chlorophyll for photosynthesis, all essential materials are both absorbed and eliminated through passive absorption

polyclonal activation

Pathogens contain multiple distinct antigenic fragments on their surface and hence a single pathogen is likely to stimulate several different T and B lymphocytes to produce a variety of specific antibodies

Organization of photosynthetic pigments into photosystems

Photosynthetic pigments absorb different wavelengths of light, so to maximize light absorption they are grouped into photosystems (with accessory pigments passing electrons to a central reaction center)

Structural adaptation

Physical difference (ex: neck length of a giraffe)

Explain how evolution occurred in the peppered moth population of England during the industrial revolution

Polymorphic variants: melanic coloration (light versus dark pigmentation) Selection pressure: predation by local birds When high levels of soot blackened the local trees during the industrial revolution, the dark moth was better camouflaged and experienced less predation (so the dark pigmentation allele became more frequent as dark moths reproduced)

5 specific actions of antibodies and outline how they contribute to the overall immune response

Precipitation: soluble pathogens become insoluble and precipitate Agglutination: Cellular pathogens become clumped for easier removal Neutralization: antibodies may occlude pathogenic regions Complement activation: complement proteins perforate membranes Acronym: PANIC -Collectively, the actions of antibodies enhance the immune system by aiding the detection (opsonization) and removal of pathogens by the phagocytic leukocytes of the innate immune system (macrophages)

Different levels of protein folding

Primary: Order/sequence of amino acids within a polypeptide chain. Formed via peptide bonds between the amine and carboxyl group of adjacent amino acids. Primary structure determines all subsequent levels of protein structures. Secondary: the folding of a polypeptide chain into repeating arrangements (alpha helices or beta-pleated sheets) (Looks kind of like RNA) Tertiary: Overall three-dimensional shape of the polypeptide chain. Formed via a variety of bonds / interactions between the variable side chain (R groups). These interactions may include hydrogen bonds, ionic bonds, disulphide bridges or hydrophobic interactions. Quaternary structure: The presence of multiple polypeptides or prosthetic groups to form a biologically active protein. Not all proteins have this form of structure.

what is endocytosis?

Process by which large substances enter the cell without crossing the membrane

Stages of mitosis

Prophase: Chromosomes condense (DNA supercoils). Nuclear membrane dissolves. Paired centrosomes move to opposite poles of the cell and start producing spindle fibres Metaphase: spindle fibres connect to centromeres of chromosomes. Contraction of spindle fibres cause chromosomes to align along the middle of the cell -Anaphase: Spindle fibres continue to contract which results in the separation of the identical sister chromatids. Each chromatid is now referred to as a chromosome. The identical chromosomes move to opposite poles -Telophase: Chromosomes decondense. Nuclear membranes reform around the two separate sets of identical chromosomes. Cytokinesis occurs concurrently to split the cell into two

Direct active transport

Protein pumps use ATP to translocate ions against their concentration gradient

role of bones

Providing anchorage for muscle attachment and acts as a lever

Purpose and products of fermentation

Purpose: Restore stock of NAD+ needed for glycolysis; allows ATO to continue to be produced in the absence of O2 (otherwise respiration would stop) -Fermentation in animals reversibly converts pyruvate to lactic acid (and frees up NAD+) -In plants, it reversibly converts pyruvate to ethanol and CO2 (frees up NAD+)

Meiosis

Reduction division of a diploid cell to produce four haploid daughter cells

Role of the nucleolus

Region in the nucleus where ribosomes are assembled

Autosome

Represent non-sex-related chromosomes

Function of the abscisic acid

Responsible for abscission and regulating transpiration

difference between smooth and rough ER

Rough ER has ribosomes and is therefore responsible for the transport of proteins Smooth ER is NOT embedded with ribosomes and is involved in the transport and synthesis of carbs and lipids

Five examples of non-coding DNA

Satellite DNA (ex: short tandem repeats) Telomeres (the terminal sections of chromosomes) Introns (non-coding sequences within DNA Non-coding genes (ex genes for tRNA or rRNA) Gene regulatory sequences (ex promoters, enhancers, silencers) Acronym: STING

saturated and unsaturated fatty acids

Saturated: lack a double bond (possess maximal amount of H atoms) Unsaturated: fatty acids possess double bonds (may be monounsaturated or polyunsaturated)

Leaf tissue

See bioninja topic 9.1 for more

H20 and CH4 (methane)

Similarities: Both have similar size and weight. They have comparable valence structures Differences: water has a higher boiling and melting point. Water has a higher specific heat capacity. this is because water is polar and can form hydrogen bonds (methane is non-polar so it cannot form H bonds)

prokaryotic ribosomes

Smaller than eukaryotic ribosomes Prokaryote = 70S ribosomes Eukaryotes - 80S ribosomes

pepsin (protease)

Source: gastric pit (stomach) substrate: proteins Product: Short polypeptides optimal pH: ~2

(Pancreatic) lipase

Source: pancreas substrate: Triglycerides product: glycerol + fatty acids optimal pH: ~8

(salivary) amylase

Source: salivary gland Substrate: starch Product: Maltose Optimal pH: ~7

spermatogenesis v oogenesis

Spermatogenesis: number of gametes produced: 4 Cytoplasmic division: equal Duration of process: continuous Timing of gamete release: lifelong (from puberty) Oogenesis: Number of gametes produced: 1 (+ polar bodies) Cytoplasmic divisions: unequal Duration of process: in staggered stages Timing of gamete release: finite (menarche to menopause)

Anaphase II

Spindle fibers contract and separate the sister chromatids, chromatids (now called chromosomes) move to opposite poles

anaphase I

Spindle fibers contract and split the bivalent, homologous chromosomes move to opposite sides of the cell

Metaphase II

Spindle fibers from opposing centrosomes attach to chromosomes (at centromere) and align them along the cell equator

Somatic versus germline mutation

Stomatic: affects body cells and cannot be inherited by offspring Germline: Affects sex cells and will be passed onto offspring

key steps required for in vitro fertilization

Stop menstrual cycle with drugs Hormone treatments (FSH triggers superovulation) Extract multiple eggs Sperm selection Fertilization (in vitro) Implantation of embryos Test for pregnancy Acronym: SHE'S FIT

Compare the use of carbs and lipids as an energy source

Storage: triglycerides=long term, carbs=short term Osmotic effects: Triglycerides have less effect on osmotic pressure (they are hydrophobic/not a solute) Digestion: carbs are easier to digest (more readily consumed and can be digested anaerobically) ATP yield: lipid digestion has higher ATP yield (~2x as much energy per gram) Solubility: Triglycerides are insoluble in water and hence harder to transport

Hydrophilic

Substances that are soluble in water (lit. "water loving)

Lock and key model

Substrate and active site are complementary in both shape and chemical properties. Enzymes are specific for reactions they catalyze.

DNA

Sugar: Deoxyribose Bases: G, C, A, T Strands: double stranded

RNA

Sugar: ribose Bases: U, A, C, G Strands: one (usually)

autotroph

Synthesize their own organic molecules from simple inorganic substances (ex: CO2, nitrates) -Energy derived from sunlight OR oxidation of molecules

Factors that can affect an enzyme's molecular motion and collision with a substrate

Temp: increases kinetic energy of particles, leading to more frequent collisions Substrate concentration: increases frequency of collisions with enzymes Enzyme concentration: increases frequency of collision with substrate

Composition of the bacterial wall

The bacterial cell wall is composed of peptidoglycan

mechanical digestion

The breakdown of food by physical actions (chewing, churning, segmentations, etc)

Assimilation

The conversion of nutrients into fluid / solid parts of the organism

Arrows in food chains/webs

The direction of energy

Homeostasis

The maintenance of a constant interval environment within physiological tolerance limits

Absorption

The movement of fluids or dissolved substances across a membrane

Simple diffusion

The net movement of particles form a region of high concentration to a region of low concentration (until equilibrium is reached)

Transcription

The process which RNA sequences are produced from DNA templates (gene)

Locus

The specific location of a gene on a particular chromosome

Hormonal factors (male)

The testes produce testosterone to develop the male sex characteristics (pre-natal development of male genitalia, production of sperm at onset of puberty and development of secondary sex characteristics)

Proteome

The totality of proteins expressed within a cell, tissue, or organism at a given time

Hemizygous

There is only one allele (occurs in males for sex chromosome ( ͡° ͜ʖ ͡°) traits)

Frameshift mutation

This mutation changes the reading of a frame, causing the codons to all be changed, resulting in a completely different protein than the one coded

Haploid cells

This nuclei possesses only one copy of each chromosome (ex: gametes = n)

relationship between the structure of the chloroplast and its function: grana

Thylakoids organized into stacks (increases SA:Vol ratio)

Differences between transmission electron micrograph and a scanning electron micrograph

Transmission electron microscopy (TEM) generate cross-sections through a specimen (internal image) Scanning electron microscopy (SEM) generates a surface rendering of a specimen

Cladogram

Tree diagram where branch points show splitting of two new groups from a common ancestor

Importance of surface size and volume

Volume: Rate of metabolism Surface area: rate of exchange between cell and environment As cell grows, volume increases faster than SA Cells therefore can't get too big or the cell will burn more nutrients than it is taking in--cell growth limited

How is DNA replication semi-conservative?

When a new double-strand molecule is formed: -One strand is from the original template molecule (conserved) -One strand is newly synthesized (not conserved)

purpose of inflammation

When tissue damage occurs, most cells and basophils release histamine which causes local vasodilation and increases capillary permeability to improve the recruitment of leukocytes to the region

Adhesion in water bonding

When two different molecules 'stick' together (via intermolecular bonding) -Water molecules are adhesive with polar or charged substances

ecosystem

a community AND its abiotic environment (ex: habitat)

Function of the ethylene

a gas which stimulates ripening

population

a group of organisms of the same species that are living in the same area at the same time

polysome

a group of ribosomes moving along an mRNA sequence simultaneously

seminal vesicle

adds nutrients (provides energy for the sperm) and secretes prostaglandins

label a tissue layer of the small intestine

also know a top-down view

purpose of the alveoli

alveoli are the small air-filled sacs within lungs that greatly increase surface area and are responsible for GAS EXCHANGE

Divergent evolution

ancestral relatedness: species share a common ancestry Evolutionary effects: adopt dissimilar phenotypic features because of different selection pressures type of adaptation: homologous structures

two water molecules bonding

awww how cute <33333333

Four plant phyla easy identification

big fillups cost a-lot

Hydrophobic

bigoted against water, so it is insoluble in water (lit. "water hating")

three examples of selection pressure

biotic factors (predators/pathogens) abiotic factors (weather events, nutrient supply, etc) random phenonena (fires, floods, earthquakes, etc)

Concentration of protein within blood plasma, filtrate and urine

blood: present Filtrate: absent urine: absent Remains in blood because of ultrafiltration

Concentration of urea within blood plasma, filtrate and urine

blood: present filtrate: present Urine: present Reason: eliminated as a nitrogen waste product

Concentration of water within blood plasma, filtrate and urine

blood: present filtrate: present Urine: present reason: variable excretion to regulate water levels in body (osmoregulation)

Concentration of glucose within blood plasma, filtrate and urine

blood: present filtrate: present urine: absent reason: it's selectively reabsorbed in tubules

codominance

both alleles are expressed within a heterozygous phenotype

overhydration

can potentially lead to tissue damage (cell lyse from osmosis)

consequences of dehydration

causes blood pressure to drop and heart rate to raise to compensate

natural active immunity

challenge and response to a pathogenic infection

polygenic inheritance

characteristics that are controlled by more than two gene loci

diagram the human lungs

check bioninja topic 6.4 for the actual image

Horomone

chemical messengers released from endocrine glands into the bloodstream to act on specific target cells

Sex chromosome ( ͡° ͜ʖ ͡°)

chromosomes that determine sex

consequences of emphysema

common symptoms of emphysema include shortness of breath, phlegm, production, expansion of the ribcage, cyanosis and an increased susceptibility of chest infections

halophytes

conditions: saltine (salty soil/water) Issues: reduced water uptake because of hypertonic. Soil conditions (high levels of salt uptake) Adaptations: cellular sequestration (salt in vacuoles). tissue partitioning (lead abscission). Salt excretion (active salt removal). Root-level exclusion (avoid salt uptake)

role of tendons

connect bone to muscle

role of ligaments

connects bone to bone

cell respiration

controlled release of energy from organic compounds to produce ATP

which blood vessels supply the heart tissue with oxygen and nutrients

coronary arteries

one diagnostic and one therapeutic use for monoclonal antibodies

diagnostic: detection of pregnancy (anti-hCG antibody) Therapeutic: treatment of cancer or rapid infection (ex: rabies)

Inhilation

diaphragm and external intercostal muscles, increasing volume of thorax pressure in the lungs is decreases, so air flows in

exhalation

diaphragm relaxes and internal intercostals contract, decreasing thoracic volume. Pressure in the lungs is increased, so air flows out

behavioral adaptation

differences in activity patterns (ex: opossums feigning death when threatened)

biochemical adaptation

differences in molecular composition/enzyme functions (ex: blood groups, lactose intolerance)

Psychological adaptation

differences in responses to vital organs (ex: homeothermy, color perception)

Pathogens

disease-causing agents (ex: microorganisms, viruses, and prions)

endocytosis in the digestive system

dissolved materials are absorbed en masse by the process of pino cytosis (cell drinking)

role of the nucleus

double membrane structure that stores DNA, and is the site of transcription (RNA synthesis)

Stabilizing selection

effects: intermediate phenotype is favored at the expense of both phenotypic extremes Example: human birth weights (too large = birthing compilations; too small = risk of death)

causes of emphysema

emphysema is the abnormal enlargement of alveoli (forms huge air spaces--'bullae') -Emphysema is often caused by smoking, as chemicals in cigs damage alveoli -The recruited phagocytes release elastase and the elastase destroys fibers in alveolar walls

fate of energy and nutrients in an ecosystem

energy flows through an ecosystem and is lost--requires resupply from a constant energy source (ex: sun) -Nutrients are finite and are recycled within a closed ecosystem

endergonic reactions

energy is absorbed (think: sounds like in-dergonic--energy goes in)

allergen

environmental substance that triggers an immune response despite not being intrinsically harmful

euchromatin versus heterichromatin

euchromatin: more loosely packed and corresponds to active segments of DNA (active genes) Heterochromatin: more densely packaged and corresponds to inactive segments of DNA -Different cells have different segments of DNA packaged a euchromatin and heterochromatin

exons

expressing sequences that are translated into protein

carnivore

feeds exclusively on animal matter

Herbivore

feeds exclusively on plant matter

omnivores

feeds on both plant and animal matter

seed dispersal

fertilized ovule (seed) moves away from parent plant to reduce competition

fertilization

fusion of male gamete nuclei (in pollen) with female gamete nuclei (in ovule)

bionomial system of nomenclature

globally recognized classification scheme whereby every organism has a two-part scientific name: genus is written first and capitalized (ex: Homo) and species following it in lower case (ex: Homo sapiens)

four substances that can be detected via urinary tests, and significance of positive samples

glucose: indicates diabetes Protein: certain diseases / hormonal conditions

example of metabolic pathways that forms a chain

glycolysis

clone

group of genetically identical cell or organism

How is the structure of the capillaries related to its function

have walls that are a single cell thick because they exchange materials between blood and tissue

genotypes of blood

here's that map

simple diffusion in the digestive system

hydrophobic materials (ex: lipids) may diffuse freely across the epithelial membrane

alternative name for an antibody

immunoglobulin

detrivore

ingest organic molecules found in non-living remnants of organisms

process of translation

initiation: small ribosomal subunit binds to mRNA and moves along it in a 5' -> 3' direction until the START codon (AUG). Specific tRNA (carrying Met) binds to the START codon (via complementary anticodon). Large ribosomal subunit binds to the tRNA molecule (via the P-site), completing the ribosome Elongation: another tRNA molecule binds to the next codon in the mRNA sequence (via the ribosomal A-site). The ribosome transfers the amino acid in the P-site to the amino acid in the A-site (via a peptide bond) Translocation: Ribosome moves one codon position along the mRNA sequence (in a 5' -> 3' direction). Deacylated tRNA molecule moves to E-site and is released, while tRNA in the A-site moves to the P-site. A new tRNA enters the empty A-site and the elongation and translocation stages are continually repeated. Termination: The ribosome reaches a STOP codon and a releasing factor is recruited. This causes the completed polypeptide chain to dissociate the ribosome to disassemble.

introns

intruding sequences within a gene that are removed prior to translation (not expressed)

Function of the cytokinin

involved in secondary growth (ex: branching)

Function of the gibberellin

involved in seed germination

role of the golgi apparatus

involved in sorting, storing, modification, and exportation of secretory products of the cell

Function of the auxin

involved in the primary growth and tropic responses

active immunity

involves the production of antibodies by the body itself and the subsequent development of memory cells

Unit of measurement in pyramids of energy

kJ (kilojules)

Bactericidal

kills the invading bacteria

example of a metabolic pathway that forms a cycle

krebs cycle (citric acid cycle) or calvin cycle

initial source of energy for almost all communities

light (from the sun)

two stages of photosynthesis

light dependent reaction light independent reaction (Calvin cycle)

biotic factors

living components of an environment which affect an ecosystem

transpiration

loss of water vapor from the leaves and stems of the plant

osmoregulators

maintain a constant osmolarity, independent of environment ex: people

osmoconformers

match their internal osmolarity to that of their environment Ex: fish

materials that are exchanged between maternal blood and fetal blood within the placenta

maternal -> fetal: nutrients, O2, and maternal antibodies will be taken up by fetus Fetal -> maternal: CO2 and toxic waste (ex: urea) will be removed by mother

Osmolarity

measure of solute concentration, as defined by osmol/L

Spirometry

measures the speed (flow) or amount (volume) of inhalation or exhalation -This data can be recorded with a spirometer

label the parts of the heart

memorize this baka

dicotyledonous flower

memorize this flower

antigen

molecules that are capable of inducing an immune response

difference between monocot roots and dicot roots

monocot: less centered and bigger veins (bigger) Dicot root: more centered and smaller veins (smaller)

Facilitated diffusion in the digestive system

monosaccharides, vitamins, and some minerals are transported by channel proteins

how efficient are most biological energy transfers

most energy transformations are only ~5-20%

why are antagonistic muscle pairs necessary

muscles can only cause movement by contracting (i.e. muscles cause movement in one direction) -To enable opposing movements, muscles must work in antagonistic pairs (resets bone back to its original position)

functional unit of a kidney

nephron

natural passive immunity

newborns receiving antibodies via mother's breast milk

structure of the nucleosome (and identify its function)

nucleosome consists of DNA and histosone proteins -DNA is wrapped around an octamer of histone proteins -Nucleosomes are linked by an interconnecting H1 histone -Nucleosomes serve two key functions -Help supercoil DNA (improved packaging) -Help to regulate transcription

Natural selection

occurs when the environment determines which adaptations are beneficial or detrimental

Type II diabetes

onset: late onset (adulthood) effects: body does not respond to inulin Cause: insulin receptors down-regulated Treatment: dietary management

Hormonal factors (female)

ovaries make estrogen and progesterone to develop the female sex characteristics (pre-natal development of reproductive organs, development of secondary sex characteristics and maintenance of menstrual cycle)

oxygen

oxidation: gain Reduction: loss

hydrogen

oxidation: loss Reduction: gain

what is the range of wavelengths absorbed via photosynthesis

photosynthesis uses the visible spectrum (white light), which ranges from 400nm to 700nm

Difference in absorbed red, green, and blue light by plants

plants predominantly absorb red and blue light, but reflects green light

antibiotic resistance and how they lead to evolution

polymorphic variants: drug-resistant versus drug-susceptible strains Selection pressure: presence of antibiotics (ex: methicillin) If exposed to an antibiotic, only the drug resistant strand survives. This increases the frequency of the drug resistant strand in the population

Photosynthesis

process by which cells use light energy to synthesize organic compounds from inorganic molecules

what is exocytosis

process by which large substances exit the cell without crossing the membrane. Vesicles fuse with plasma membrane, expelling heir contents into the extracellular environment. Exocytosis adds vesicular phospholipids to the ell membrane, replacing those lost via endocytosis

translation

process of protein synthesis, whereby genetic information encoded in the mRNA is translated into an amino acid sequence at the ribosome

three sections of a gene

promoter - initiation point (where RNA polymerase binds) Coding region - Sequence that is transcribed -Terminator - termination point

antibody

proteins produced by lymphocytes that recognize and neutralize specific antigens

role of muscles

provide the force required for the movement of bones

decomposer

release digestive enzymes and then absorb the external products of digestion

Exergonic reaction

release energy (think: Ex(it)gonic--energy exits/leaves)

direction of DNA replication

replication occurs in a 5' -> 3' direction (on the newly synthesized strand)

photoperiodism

response of a plant to the length of day or night

role of the mitochondria

responsible for aerobic respiration

role of the ribosomes

responsible for protein synthesis and an be found freely within the cytosol or may be embedded in the rough ER

role of lysosomes

responsible for the breakdown of macromolecules (digests toxic metabolites too)

Passive immunitty

results from the acquisition of antibodies from another source and hence memory cells are not as developed

prostate gland

secretes alkaline fluids which help to neutralize vaginal acids

Label a chromosome

see Bioninja's website on topic 3.1's note packet for this activity

testis tissue

see bioninja topic 11.4 for more

carbon cycle

see bioninja topic 4.3 for the diagram

Label a diagram of a seed

see bioninja topic 9.4 for more

role of sensory neurons

sends signals from receptors to the central nervous system

role of motor neurons

sends signals from the central nervous system to effectors

role of relay neurons

sends signals within the central nervous system

dihybrid crosses

set up the possible genotypes, and do a system similar to foil, and then you SHOULD see a 9x3x3x1 for a normal dihybrid cross

'blunt' and 'sticky end' restriction endonucleases

sticky ends are overhanging sequences which allow for specificity in ligation (only complementary sequences can ligate together) -- blunt ends have no overhang

gene pool

sum of all genes (and their alleles) present in an interbreeding population

bacteriostatic

suppresses its potential to reproduce

tap roots

tap roots penetrate deeply (for stability) and have many connected lateral branches

Chemical digestion

the breakdown of food by chemical agents (stomach acids, bile, enzymes)

State the composition of a plant cell wall

the cell wall of a plant cell is composed of cellulose

habitat

the environment in which a species normally lives, or the location of a living organism

gas exchange

the exchange of O2 and CO2 between the alveoli and bloodstream (via diffusion)

ventilation

the exchange of air between atmosphere and lungs--achieved by the physical act of breathing

What is the threshold potential represent

the minimum level of depolarization required for an action potential to occur (all or nothing rule)

different parts of the mitochondria

the part below the blue kool-aid is the intermembrane space

excretion

the removal from the body waste products of metabolic activity

biomass

the total dry weight of organic matter in organisms or ecosystem

adaption to the kidneys of desert mammals that increases water conservation

these animals have a longer loop of Henle (increased water absorbtion)

fibrous roots

these roots are thin and very spread out

genome

totality of genes in a cell, organism, or organelle

pollination

transfer of pollen from the anther to the stigma (usually between different plants)

active passive immunity

transfusion of monoclonal antibodies (ex: treatment of rabies)

define cancer

uncontrolled cell proliferation

What waste products do mammals produce

urea (which is non-toxic and so can be stored at higher concentrations)

What waste products do birds produce

uric acid (requires minimal water to flush)

artificial active immunity

vaccination

adhesion in plants

water molecules form polar associations with the wall of the xylem vessel

Cohesion

water molecules stick together by H-bonding

most common greenhouse gas

water vapor

herd immunity

when individuals who are not immune to a pathogen are protected from exposure by the large amounts of immune individuals (usually >95%) within a community

role of epididymus

where sperm matures and develops capacity to 'swim'