Genetics and Molecular Biology Concepts, Exams of Biology

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IB Biology Exam with correct answers

How do you calculate the magnification of a drawing/image?

• .......🔷ANSWERS🔷......✔✔ Magnification=Image size(with ruler) / Actual size(according to scale bar) How do you calculate the actual size of a magnified specimen?
• .......🔷ANSWERS🔷......✔✔ Actual size=Image size(with ruler) / magnification By which process do potassium ions move through potassium channels in axons?
• .......🔷ANSWERS🔷......✔✔ Facilitated diffusion -at rest, the Na-K+ pump expels Na+ ions out of cell, while K+ are put within -when the neuron fires--> the ions swap locations via facilitated diffusion via Na- K+ channels What is the theory of endosymbiosis? - .......🔷ANSWERS🔷......✔✔ -eukaryotic cells are believed to have evolved from early prokaryotes that were engulfed by phagocytosis -the engulfed prokaryotic cell remained undigested -contributed new functionality to the engulfing cell -over generations, the engulfed cell lost some of its independent utility and became a supplemental organelle What general evidence supports the theory of endosymbiosis?
• .......🔷ANSWERS🔷......✔✔ -membranes have a double membrane bound -antibiotics(susceptibility) -division(mode of replication) -DNA(presence and structural composition) -ribosomes(size)

How do mitochondria and chloroplasts provide evidence for endosymbiosis?

• .......🔷ANSWERS🔷......✔✔ eukraryotic mitochondria and chloroplasts have their own circular DNA What are the phases of cell cycle? - .......🔷ANSWERS🔷......✔✔ 1. Interphase

2. Mitosis
3. Cytokinesis What are the phases of interphase? What are their roles? - .......🔷ANSWERS🔷......✔✔
4. First growth phase(G1)=growth and normal metabolic roles
5. Synthesis(S)=DNA replication
6. Second growth phase(G2)=growth and preparation for division What visually occurs during interphase? - .......🔷ANSWERS🔷......✔✔ -DNA is present as uncondensed chromatin(not visible under microscope) -DNA is contained with a clearly defined nucleus -Centrosomes and other organelles have been duplicated -Cell is enlarged for preparation for division What are the phases of mitosis? - .......🔷ANSWERS🔷......✔✔ prophase, metaphase, anaphase, telophase peter makes apple toast What happens during prophase? - .......🔷ANSWERS🔷......✔✔ -DNA supercoils and chromosomes condense(becoming visible under microscope) -Chromosomes are comprised of genetically identical sister chromatids(joined at centromere) -paired centrosomes move to opposite poles -spindle fibers form -nuclear membrane breaks down -nucleus dissolves

What happens during metaphase? - .......🔷ANSWERS🔷......✔✔ -spindle fibers from bother centromeres connect to the centromere of each chromosome -microtubule depolymerisation-->spindle fibers shorten in length and contract -chromosomes align along the center of the cell(metaphase plate) What happens during anaphase? - .......🔷ANSWERS🔷......✔✔ -genetically identical sister chromatids separate(caused by contraction of spindle fibers) -once the chromatids separate, they are considered individual chromosomes -genetically identical chromosomes move to opposite poles what happens during telophase? - .......🔷ANSWERS🔷......✔✔ -once the chromosome sets arrive at the poles, spindle fibers dissolve -chromosomes decondense(no longer visible under light microscope) -nuclear membranes reform around each chromosome set what is cytokinesis? - .......🔷ANSWERS🔷......✔✔ -process of cytoplasmic division -cell splits into identical daughter cells -different in plants and animals how does cytokineses occur in animal cells? - .......🔷ANSWERS🔷......✔✔ -after anaphase-->microtubules filaments form a concentric ring around the center of the cell -microfilaments form a cleavage furrow -when the furrows meet in the center, the cell pinches off and forms two new cells -centripetal=separation occurs from outside to inside how does cytokineses occur in plant cells? - .......🔷ANSWERS🔷......✔✔ -after anaphase--> carbohydrate-rich vesicles form in a row at the center of the cell -vesicles fuse together -early cell plate forms at the middle of the cell

-cell plate extends outwards and fuses with the cell wall -dividing the cell into two distinct daughter cells -centrifugal=separation occurs from inside to outside what is the mitotic index? why is it important? - .......🔷ANSWERS🔷......✔✔ -the ratio of dividing cells in a cell population -prognostic tool in predicting the response of cancer cells to chemotherapy how do you calculate mitotic index? - .......🔷ANSWERS🔷......✔✔ number of cells in mitosis/total number of cells calculate the mitotic index based on the following amount of cells in each stage: prophase= metaphase= anaphase= telophase= interphase=30 - .......🔷ANSWERS🔷......✔✔ total= number in mitosis= 20/50=0. explain the difference between catabolism and anabolism/their type of rxt

• .......🔷ANSWERS🔷......✔✔ 1. catabolism=breakdown of complex molecules into simpler molecules-->hydrolysis rxts breakdown macromolecules into monomers

2. anabolism=synthesis of complex molecules from simpler molecules--

condensation rxt forms macromolecules from monomers In which processes are macromolecules broken down into monomers?

• .......🔷ANSWERS🔷......✔✔ catabolism and hydrolysis Which molecule in the body is most suitable long-term energy storage in humans? what does it look like? - .......🔷ANSWERS🔷......✔✔ triglycerides

What are properties of water? - .......🔷ANSWERS🔷......✔✔ -dipolarity allows for polar associations with other charged molecules(polar or ionic; adhesion) -high specific heat capacity -highly cohesive(important for transport in xylem; can form hydrogen bonds) -high heat of vaporization -high heat of fusion -high melting/boiling point -polar be able to read/analyze nomograms - .......🔷ANSWERS🔷......✔✔ how are enzyme activity affected by temperature? - .......🔷ANSWERS🔷......✔✔ -too low temperature=insufficient thermal energy for the activation of an enzyme- catalyzed rxt to proceed -too high temperature=enzyme stability decreases-->thermal energy disrupts the enzyme's hydrogen bonds -optimal temperature=rate of enzyme activity will be at its peak how is enzyme activity affected by substrate concentration?

• .......🔷ANSWERS🔷......✔✔ -higher substrate concentration=increased activity of a corresponding enzyme -increased chance of enzyme and substrate colliding in a given period What effect do changes in pH have on enzymes? a. all enzymes increase in activity as pH increases b. the activity of all enzymes is reduced by a pH above or below 7 c. low pH causes reversible denaturation in all enzymes d. extreme pH can alter the active site of all enzymes - .......🔷ANSWERS🔷......✔✔ -d -each enzyme has its own optimal pH, and a drastic change causes irreversible damage

For what did Messelon and Stahl's work provide evidence for?

• .......🔷ANSWERS🔷......✔✔ -the semi-conservative replication of DNA -when a double-stranded DNA molecule is formed, one strand will be from the original template molecule, and the other will be newly synthesized -occurs b/c each nitrogenous base can only pair with its complementary partner what are the nitrogenous base pairs? - .......🔷ANSWERS🔷......✔✔ adenine and thymine(apples in tree) cytosine and guanine(car in garage) both anaerobic and aerobic respiration begins with... - .......🔷ANSWERS🔷......✔✔ - glycolysis -breaks down glucose(6-carbon) into two molecules or pyruvate(3C) -small yield of ATP(2 molecules) briefly explain anaerobic respiration - .......🔷ANSWERS🔷......✔✔ -occurs in absence of O -does not produce ATP molecules -restores stocks of NAD+- (molecule needed for glycolysis) -in animals: pyruvate is converted to lactic acid(lactate) -in plants and yeast: the pyruvate is converted to ethanol/CO which compound is a waste product of anaerobic respiration in humans? a. CO b. ethanol c. lactate d. pyruvate - .......🔷ANSWERS🔷......✔✔ -correct=d -CO2 and ethanol and produced in plants/yeast -pyruvate is what's being converted, not produced -lactate production in humans maximizes power of muscle contractions

briefly explain aerobic respiration - .......🔷ANSWERS🔷......✔✔ -requires O2 and occurs in mitochondria -pyruvate is broken down into CO2 and H2O -yields large amount of ATP(34-36 molecules) -consists of the link reaction, krebs cycle, and electron transport chain what are respirometers? what are they composed of? - .......🔷ANSWERS🔷......✔✔ - device that measures an organism's respiration rate by the rate of exchange of O and CO -living specimen=enclosed in sealed container -CO2 production=measured by data logger or pH change(if the specimen is immersed in water) -oxygen consumption=measured by change in pressure(can be detected using manometer) which factors detect respiration rate? - .......🔷ANSWERS🔷......✔✔ 1. increase in CO levels-->indicates an increase in respiration rate(product of aerobic respiration)

2. decrease in O2 levels-->indicates an increase in respiration(O2=requirement of aerobic respiration) What is the expected direction of movement for the fluid in the manometer and the function of the fluid with the specimen? a. down, absorb CO b. down, produce O c. up, absorb CO d. down, produce O2 - .......🔷ANSWERS🔷......✔✔ -fluid moves down -function of other=absorb CO If a karyotype shows an XY sex chromosome, and two chromosomes at the 22nd chromosome, then... a. child=female with down syndrome

b. female without DS c. male with DS d. male withou DS - .......🔷ANSWERS🔷......✔✔ d. male w/o DW -chromosome XY=male -DS requires three chromosomes A variety of Pelargonium has yellow leaves. When plants of this variety are crossed, the resulting seeds produce green, yellow, and white seeding in the ratio 1:2:1. If plants with yellow leaves are crossed with green-leaved plants, what would the expected phenotypes of the offspring be? - .......🔷ANSWERS🔷......✔✔ green=2, yellow=2, white= explain the key for pedigree charts - .......🔷ANSWERS🔷......✔✔ -male=square -female=circle -shaded=affected, unshaded=not -horizontal line between male and female=mates -left to right=oldest to youngest Explain autosomal dominant inheritance - .......🔷ANSWERS🔷......✔✔ -if BOTH parents are affected & an offspring is UNAFFECTED=trait must be dominant -affected individuals MUST have at least one affected parent -if both parents are unaffected, the offspring must ALSO be unaffected(homozygous recessive) -will see affect in every generation explain autosomal recessive inheritance - .......🔷ANSWERS🔷......✔✔ -if both parents are UNAFFECTED & an offspring is AFFECTED=trait must be recessive -if both parents SHOW the trait, an offspring must ALSO have the trait(homozygous recessive) explain the general concept of determining x-linked inheritance

• .......🔷ANSWERS🔷......✔✔ -it is not possible to confirm sex linkage from pedigree charts b/c autosomal traits could generate the same results

-BUT certain trends can be used to confirm that a trait is not x-linked dominant or recessive explain x-linked dominant inheritance - .......🔷ANSWERS🔷......✔✔ -if a male shows a trait, so must ALL his daughters and his MOTHER -an unaffected mother cannot have affected SONS or FATHER -tend to be more common in females explain X-linked recessive inheritance - .......🔷ANSWERS🔷......✔✔ -if a female shows a trait, so must ALL her sons and her FATHER -an unaffected mother can have affected sons IF she is a carrier(heterozygous) -tend to be more common in males what is PCR used for? - .......🔷ANSWERS🔷......✔✔ to separate fragments of DNA by size define species - .......🔷ANSWERS🔷......✔✔ a group of organisms that can interbreed to produce fertile, viable offspring define population - .......🔷ANSWERS🔷......✔✔ a group of organisms of the same species, living in the same area @ the same time define community - .......🔷ANSWERS🔷......✔✔ a group of populations living together and interacting with each other in a given area define habitat - .......🔷ANSWERS🔷......✔✔ the environment in which a species normally lives, or the location of a living organism define ecosystem - .......🔷ANSWERS🔷......✔✔ A community and its abiotic environment(ex=habitat) define ecology - .......🔷ANSWERS🔷......✔✔ the study of the relationship between living organisms, or between living organisms and their environment

diagram of the largest mass of carbon per year(ask peano)

• .......🔷ANSWERS🔷......✔✔ what material is formed when organic matter is not fully decomposed in acidic waterlogged soils? - .......🔷ANSWERS🔷......✔✔ peat what are the two key limitations to using morphological differences as a basis for classification? - .......🔷ANSWERS🔷......✔✔ adaptive radiation(divergent) and convergent evolution define convergent evolution - .......🔷ANSWERS🔷......✔✔ -independent evolution of similar features in species with distinct lineages -may occur when different species occupy the same habitat, making them subjected to the same selection pressures -common adaptation causes structural similarity -ex=wings in birds, bats, and insects explain homologous structures and give an example - .......🔷ANSWERS🔷......✔✔ - traits that are similar b/c they derived from a common ancestor -arise via divergent evolution -example=pentadactyl limb in vertebrates -similar structure, different function explain analogous structures and give an example - .......🔷ANSWERS🔷......✔✔ -due to common selective pressures -arise via convergent evolution -example=wings in insects, birds, and bats -different structure, similar function state the seven main taxonomic ranks - .......🔷ANSWERS🔷......✔✔ Kingdom(katy) Phylum(perry)

Class(comes) Order(over) Family(for) Genus(grape) Species(soda) the kingdom animalia can be subdivided into two main groups..

• .......🔷ANSWERS🔷......✔✔ 1. invertebrates(no backbone)

2. vertebrates( chordata) describe characteristics of the porifera phylum - .......🔷ANSWERS🔷......✔✔ - asymmetrical -no mouth or anus -silica/calcium carbonate for structural support -ex=sea sponges -invertebrate describe characteristics of the cnidaria phylum - .......🔷ANSWERS🔷......✔✔ -radial symmetry -mouth -no anus -may have tentacles w/ stinging cells for prey -ex=jellyfish -invertebrate describe characteristics of the Platyhelmintha phylum - .......🔷ANSWERS🔷......✔✔ - bilateral symmetry -mouth -no anus -flattened body shape to increase SA:VOL ratio

-may be parasitic -ex=tapeworms -invertebrate describe characteristics of the Annelida phylum - .......🔷ANSWERS🔷......✔✔ - bilateral symmetry -separate mouth and anus -body composed of ringed segments w/ specialization of segments -ex=earthworms and leeches -invertebrate describe characteristics of the Mollusca phylum - .......🔷ANSWERS🔷......✔✔ - bilateral symmetry -separate mouth and anus -body composed of visceral mass, muscular foot, and a mantle(possibly shell) -ex=snails, slugs, octopi, squid -invertebrate describe characteristics of the Arthropoda phylum - .......🔷ANSWERS🔷......✔✔ - bilateral symmetry -separate mouth and anus -jointed body sections, hard exoskeleton -ex=insects, spiders, centipedes -invertebrate describe characteristics of the chordata phylum - .......🔷ANSWERS🔷......✔✔ - bilateral symmetry -separate mouth and anus -notochord and a dorsal nerve for some period of their life -ex=mammals, birds, reptiles

an organism has the following characteristics, what phylum would it most likely be classified in? -single opening for digestion and egestion -radial symmetry -tentacles with stinging cells a. anneilada b. cnidaria c. platyhelminthes d. porifera - .......🔷ANSWERS🔷......✔✔ b. cnidaria give an example of a member of filicinophyta - .......🔷ANSWERS🔷......✔✔ ferns explain the four main tissue layers of the small intestine from outer to center

• .......🔷ANSWERS🔷......✔✔ 1. serosa=protective outer covering composed of a layer of cells reinforced by fibrous connective tissue

2. muscle layer=outer layer of longitudinal muscle and inner layer of circular muscle
3. submusoca=composed of connective tissues separating the muscle layer from the inntermost musoca
4. mucosa=highly folded inner layer which absorbs material through its surface epithelium from the intestinal lumen which part of the body secretes amylase, lipase, and endopeptidase for use in digestion of food? a. mouth b. pancreas c. stomach d. small intestine - .......🔷ANSWERS🔷......✔✔ b. pancreas after a red blood cell picks up oxygen in the lungs, which pathway could it take when passing through the heart during its circuit of the body?

• .......🔷ANSWERS🔷......✔✔ pulmonary veins-->L atrium-->bicuspid valve-->L ventricle-->aortic valve-->aorta-->body after blood has passed through the body(and is low in oxygen), what path does it take through the heart in order to travel to the lungs? - .......🔷ANSWERS🔷......✔✔ superior vena cava-->R atrium-->tricuspid valve-->R ventricle-->pulmonary valve--

pulmonary artery what is non-specific immunity to disease? - .......🔷ANSWERS🔷......✔✔ endocytosis of pathogens by white blood cells how do your find the threshold potential of a cell looking at an action graph?

• .......🔷ANSWERS🔷......✔✔ The number that the line begins at what is the role of the hormone leptin? - .......🔷ANSWERS🔷......✔✔ to inhibit appetite how does the hormone FSH fluctuate during the menstrual cycle?
• .......🔷ANSWERS🔷......✔✔ -low during beginning of cycle -rise at day 14 -drops again -increases at the end again explain the processes through action potential - .......🔷ANSWERS🔷......✔✔ 1. resting state

2. threshold
3. depolarization
4. repolarization
5. refractory period
6. resting state

in a normal resting period, sodium ions are predominantly _________ the neuron, and potassium ions are mainly _____________ - .......🔷ANSWERS🔷......✔✔ outside, inside what occurs during depolarization? - .......🔷ANSWERS🔷......✔✔ -sodium channels open within the membrane of the axon -potassium channels close -influx of sodium into the cell causes it to become more positive(depolarization--cell is meant to be more negative on the inside) what occurs during repolarization? - .......🔷ANSWERS🔷......✔✔ -sodium channels close -potassium channels open -passive efflux of potassium out of the cell -causes membrane potential to become more negative what occurs during the refractory period? - .......🔷ANSWERS🔷......✔✔ -period of time following a nerve impulse before the neuron is able to fire again -following depolarization(sodium influx) and repolarization(potassium efflux), the ion distribution is reversed -sodium and potassium channels are closed, Na+K+ pump opens to even ion concentrations -before a neuron can fire again, resting potential must be restored by the pump what will a graph look like that expresses a cell's surface area to volume ratio?

• .......🔷ANSWERS🔷......✔✔ curved decrease then level An image shows an electron micrograph part of a cell. What does the nucleus and chloroplasts? a. they are surrounded by a double membrane b. they contain 70S ribosomes c. they contain naked DNA

d. they are only found in leaf cells - .......🔷ANSWERS🔷......✔✔ a. they are surrounded by a double membrane a mammalian fetus is beginning to develop in the womb. which of the following changes/processes is necessary to occur? a. egg production--meiosis b. embryonic development--cell differentiation c. excretion--exocytosis d. feeding--phagocytosis - .......🔷ANSWERS🔷......✔✔ b. embryonic development--cell differentiation Which process(es) occur(s) by osmosis? a. uptake of water by cells in the wall of the intestine b. loss of water from a plant cell in a hypertonic enviornment c. evaporation of water from sweat on the skin surface - .......🔷ANSWERS🔷......✔✔ a & b only What do disaccharides consist of? - .......🔷ANSWERS🔷......✔✔ -sugar formed when two monosaccharides are joined by glycosidic linkage Which substance must be transported in the blood by lipoprotein complexes? a. cholesterol b. oxygen c. sodium chloride d. amino acids - .......🔷ANSWERS🔷......✔✔ a. cholesterol What is found in insulin molecules? a. phosphates b. nucleotides c. peptide bonds d. glycerol - .......🔷ANSWERS🔷......✔✔ c. peptide bonds

what are the general amino acid pairs? - .......🔷ANSWERS🔷......✔✔ cytosine-- guanine adenine--thymine what is the exception to the amino acid pairs when translating DNA and mRNA sequences? - .......🔷ANSWERS🔷......✔✔ A(dna)--U(mrna) what is the exception to the amino acid pairs when translating mRNA and tRNA sequences? - .......🔷ANSWERS🔷......✔✔ U(m)--A(t) A(m)--U(t) The gene that codes for a particular polypeptide includes the base sequence showed below. What is the base sequence of the mRNA molecule which is complimentary to this sequence? GAGTACCCT - .......🔷ANSWERS🔷......✔✔ CUCAUGGGA the system of sex determination in chimpanzees is the same as in other mammals. A chimpanze has 48 chromosomes in the nuclei of its body cells. What can be deduced from this information? a. the sex of the chimpanzee b. the number of genes in each chromosome c. whether non-disjunction has ocurred d. the number of autosomes in a diploid cell - .......🔷ANSWERS🔷......✔✔ d. the number of autosomes in a diploid cell at which stage of meiosis are bivalents formed? a. interphase b. prophase I c. prophase II d. metaphase II - .......🔷ANSWERS🔷......✔✔ b. prophase I bivalent=structure of two homologous chromosomes

creeper in chicken is a condition where the chicken is born with very short legs. The creeper allele(C) is dominant over the normal allele(c). Embryos which are homozygous for the dominant allele will fail to develop into viable chickens and die before they hatch. What phenotypic ratio would you expect in the live offspring of a cross between two creeper chickens? a. all creeper b. 1 creeper; 2 normal c. 2 creeper; 1 normal d. 3 creeper; 1 normal - .......🔷ANSWERS🔷......✔✔ c. 2 creeper; 1 normal Explain red-green color blindness - .......🔷ANSWERS🔷......✔✔ -genetic disorder -mutation to the red or green retinal photoreceptor--located on the X chromosome what are heterotrophs? - .......🔷ANSWERS🔷......✔✔ -they obtain organic molecules from other organisms via different feeding mechanisms/food sources -classified according to food source what are consumers by definition? - .......🔷ANSWERS🔷......✔✔ heterotrophs that feed on living/recently killed organisms by ingestion what are the three kinds of consumers? - .......🔷ANSWERS🔷......✔✔ herbivoes=feed on plant matter carnivores=feed on animal matter omnivores=diet composed of plant and animal matter what are scavengers? - .......🔷ANSWERS🔷......✔✔ -type of consumer -feeds on dead/decaying carcasses rather than hunting prey -vultures what are detrivores? - .......🔷ANSWERS🔷......✔✔ -heterotrophs that obtain organic nutrients from detrius or humus via internal digestion

-detrius=organic material/fecal matter -earthworms what are sapotrophs? - .......🔷ANSWERS🔷......✔✔ -heterotrophs that obtain organic nutrients from dead organisms via external digestion -do not ingest food -use enzymatic secretion to facilitate external digestion -bacteria, fungi which organism can be best described as a saprotoph? a. a fungus that digests its food externally and absorbs the products of digestion b. a beetle that feeds by ingesting the dung of other animal species and digesting its food internally c. a single-celled eukaryote that is able to photosynthesize and consumes smaller organisms by endocytosis d. a giraffe that feeds by ingesting leaves from an acadia tree

• .......🔷ANSWERS🔷......✔✔ a. a fungus that digests its food externally and absorbs the products of digestion` explain each of the trophic levels - .......🔷ANSWERS🔷......✔✔ 1. producer, trophic level 1=occupy first level in feeding sequence

2. primary consumer, trophic level 2=feed on producers
3. secondary consumer, trophic level 3=feed on primary consumers
4. teritary consumers, trophic level 4=feed on secondary consumers which organisms produce methane in anaerobic enviornments such as waterlogged soils? a. arachaea b. fungi c. eukaryotes d. eubacteria - .......🔷ANSWERS🔷......✔✔ a. archaea

which are examples of homologous structures? a. wings of bats and butterflies b. fins of fish and whales c. hindlimbs of frogs and grasshoppers d. forelimbs of primates and penguins - .......🔷ANSWERS🔷......✔✔ d. forelimbs of primates and penguins which is an example of natural selection? a. a giraffe stretching its neck to reach higher levels b. a juvenile bird learning to sing c. development of antibiotic resistance in bacteria d. selective breeding in tail-less cats - .......🔷ANSWERS🔷......✔✔ c. development of antibiotic resistance in bacteria where in the human body is lipase produced? a. stomach b. pancreas c. gall bladder d. liver - .......🔷ANSWERS🔷......✔✔ b. pancreas which feature of capillaries distinguishes them from arteries and veins? a. narrow diameter b. valves to prevent backflow c. thick muscular walls d. elastic tissue - .......🔷ANSWERS🔷......✔✔ a. narrow diameter what happens when you get a cut on your skin? - .......🔷ANSWERS🔷......✔✔ 1. tissue damage

2. clotting factors from plateletes, damaged cells, and plasma

3. enzymatic cascade
4. thrombin is converted to fibrinogen
5. fibrinogen is converted to fibrin
6. scar forms which statement applies to HIV? a. HIV infects red blood cells resulting in decrease production of hemoglobin b. HIV can be effectively treated sing antibiotics c. HIV can only be transmitted by sexual intercourse d. HIV causes a reduction in production of antibodies - .......🔷ANSWERS🔷......✔✔ d. HIV causes a reduction in production of antibodies what happens at the peak of an action potential curve? a. sodium channels close b. calcium channels close c. sodium channels open d. potassium channels close - .......🔷ANSWERS🔷......✔✔ a. sodium channels close where are estrogen and progesterone produced? where are FSH and LH produced? - .......🔷ANSWERS🔷......✔✔ estrogen and progesterone=ovaries; LH and FSH=pituitary glans Cultivated rice, Oryza sativa, is one of the most important human foods. The two main sub-species of cultivated rice are O. sativa indica and O. sativa japonica. O. rufi pogon is a wild species from which they probably evolved. State the reason that O. sativa and O. rufi pogon are classified as different species.

• .......🔷ANSWERS🔷......✔✔ Organism cannot interbreed to produce fertile offspring=definition of species the O. sativa indica has a much larger amount of the ancestral allele for all of is three genes, meaning that it is.... - .......🔷ANSWERS🔷......✔✔ more closer related to their shared ancestor than the other two roots

state one function of having a control group - .......🔷ANSWERS🔷......✔✔ need something to compare the testing variables to outline the function of codons - .......🔷ANSWERS🔷......✔✔ -has three bases -on mRNA -codes for one amino acid use the following sequence of mRNA to determine the amino acids AUGAGCCGAAGGUAGCUG - .......🔷ANSWERS🔷......✔✔ methionine(AUG), serine(AGC), arginine(CGA), arginine(AGG), stop(UAG) determine the DNA base sequence transcribed to form this sequence of mRNA AUGAGCCGAAGGUAGCUG - .......🔷ANSWERS🔷......✔✔ TAC TCG GCT TCC ATC GAC suggest a hypothesis that accounts for the slightly different meaning of some codons in a very limited number of organisms - .......🔷ANSWERS🔷......✔✔ genetic code is not universal state the type of reaction that removes water while linking amino acids together to form polypeptides - .......🔷ANSWERS🔷......✔✔ dehydration synthesis(or condensation) reaction state the function of Rubisco in relation to its three-dimensional conformation

• .......🔷ANSWERS🔷......✔✔ -function=enzyme involved in light independent stage of photosynthesis -globule protein allows for 3D structure state the function of spider silk in relation to its three-dimensional conformation
• .......🔷ANSWERS🔷......✔✔ -function=fiber spun by spiders to form webs -collagen protein allows for linear conformation & 3D shape

outline cell theory - .......🔷ANSWERS🔷......✔✔ 1. all living things must be composed of cells(or cell products)

2. cell is the smallest unit of life
3. cells can only arise from pre-existing cells state the functions of life(1/2) - .......🔷ANSWERS🔷......✔✔ -metabolism=L.T. have essential chemical rxts -reproduction=L.T produce offspring -sensitivity=L.T respond to external and internal stimuli -homeostasis=L.T. maintain stable internal environment state the functions of life(2/2) - .......🔷ANSWERS🔷......✔✔ -excretion=L.T. exhibit removal of waste products -nutrition=L.T. exchange materials and gases with the environment -growth=L.T. can move and change shape or size list three characteristics of eukaryotic homologous chromosomes

• .......🔷ANSWERS🔷......✔✔ -same size, shape, and order of genes -both present in diploid cell -both associated with histones in anaerobic cell respiration, a very small yield of ATP occurs in both yeasts/plants and humans. Do they both require oxygen? Do they both produce ethanol/CO2? Do they both produce lactate? - .......🔷ANSWERS🔷......✔✔ -neither require oxygen -plants/yeast produce ethanol/CO2 -humans product lactate State the immediate consequence of a species producing more offspring than the environment can support. - .......🔷ANSWERS🔷......✔✔ -lack of resources causes competition among a species

Explain the consequence of overpopulation on the survival and reproduction of better adapted individuals within a population. - .......🔷ANSWERS🔷......✔✔ -natural selection -individuals with beneficial traits will live long enough to pass genes onto offspring -causes better adapted individuals in a population be able to draw/label the Singer-Nicolson model of an animal cell membnrane

• .......🔷ANSWERS🔷......✔✔ Outline the principles used by scientists to classify organisms.
• .......🔷ANSWERS🔷......✔✔ -taxonomy -binomial classification -domains -kingdoms -molecular biology -sequencing proteins/amino acids -similar clade/branch Explain the movement of energy and inorganic nutrients in an ecosystem.
• .......🔷ANSWERS🔷......✔✔ -energy flows, not cycles -heterotrophs -carbon cycle -food chain -energy is not recycled, matter is Outline how two parents could have a child with any of the four ABO blood groups.
• .......🔷ANSWERS🔷......✔✔ -parent 1 needs Ai blood type -parent 2 needs Bi -makes every square in the punnet square different

What feature of both striated muscle and aseptate fungal hyphae is different from typical cell structure? A. They have multiple nuclei within a structural unit. B. They have a cell wall that is not made of cellulose. C. They have plasmids. D. They have an absence of cholesterol in the plasma membrane.

• .......🔷ANSWERS🔷......✔✔ A. They have multiple nuclei within a structural unit. Common pesticides used by gardeners contain neonicotinoids. What is the effect of a neonicotinoid pesticide on the transmission of a nerve impulse between neurons in an insect? A. It prevents the release of acetylcholine from the presynaptic membrane. B. It widens the synaptic cleft so diffusion of acetylcholine across the gap is slower. C. It irreversibly binds with acetylcholine receptors on the postsynaptic membrane. D. It interferes with the enzymatic breakdown of acetylcholine by acetylcholinesterase. - .......🔷ANSWERS🔷......✔✔ C. It irreversibly binds with acetylcholine receptors on the postsynaptic membrane. How does potassium move across the membrane of a neuron during repolarization? A. Simple diffusion B. Facilitated diffusion C. Endocytosis D. Active transport - .......🔷ANSWERS🔷......✔✔ B. Facilitated diffusion Which organelle provides evidence that eukaryotic cells originated when large prokaryotes engulfed small free-living prokaryotes? A. Chloroplast B. Nucleoid C. 80S ribosome D. Vacuole - .......🔷ANSWERS🔷......✔✔ A. Chloroplast