Cell Biology and Biochemistry, Exams of Advanced Education

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DAT NATURAL SCIENCES PRACTICE EXAM

TERMS 2023- 2024

what does the endodermis do? - Answer regulates passage of substances from the soil into the vascular cylinder What is allelopathy? - Answer the chemical inhibition of one plant (or other organism) by another, due to the release into the environment of substances acting as germination or growth inhibitors. What is intraspecific competition? - Answer competition between members of the same species What is a deuterostome? - Answer blastopore becomes anus What is a protostome? - Answer Type of coelomate whose mouth develops before the anus What are peripheral proteins? how could you take them off? what does centrifugation do? - Answer They are bound to the surface of the membrane;;;;; by changing the salt concentration;;;;;;; disrupts cell membrane and releases its contents and fragments What do detergents do? what is the difference between microtubles and microfilaments? - Answer solubilize membranes and disrupt proteins;;;;; microtubules are at centrioles, and microfilaments are in muscles and composed of actin Glycolysis is exergonic because it releases energy overall;;; what are fungi cell walls made up of that make them unique? Oligodendrocytes = CNS Schwann cells = PNS - Answer glucans and chitin Fish in freshwater environments:? In contrast, fish in saltwater environments (i.e. marine fish): NAME characteristics - Answer Are hyperosmotic relative to their environment Drink very little water Salt enters the gills via active transport Produce large volume of urine Are hypoosmotic relative to their environment Constantly drink Salt leaves the gills via active transport

Produce low volume of urine what is the function of the allantois? - Answer Storage of waste until the placenta takes over, early blood formation and development of the urinary bladder. What is aneuploidy? - Answer Abnormal number of chromosomes. What is brackish water? Which biome is characterized as the largest biome on Earth with long harsh, snowy winters, short rainy and humid summers and with a landscape dominated by conifers? - Answer salt water;;;; Taiga what is a deciduous forest biome? what is a chaparral biome? - Answer cold winters with warm summers and moderate levels of precipitation and soil is rich;;;;; highly seasonal precipitation with rainy winters and dry summers. Embryonic mesoderm in humans develops into what? - Answer muscle and connective tissue which includes blood and bone, as well as circulatory and reproductive systems what does the embryonic ectoderm become? - Answer epidermis and nervous system including the brain what will the embryonic endoderm become? - Answer epithelial lining of respiratory tract and digestive tract which includes glands accessory organs like liver and pancreas What is the concentration of Bi3+ in a saturated solution containing 0.01 M of S2-? Assume the Ksp of bismuth sulfide is 10-70. - Answer Bismuth sulfide dissolves in water as follows: Bi2S3(s) ↔ 2Bi3+(aq) + 3S2-(aq) Ksp = [Bi3+]2 [S2-]3 = 10- 70 Therefore, [Bi3 ]2 = 10-70 / [S2-] = 10^-70 /( 0.01)^ = 10^-70 / 10^-6= 10^- 64 *Bi3++ =√10^- 64 = 10-32 M What is parthenogenesis? - Answer The spontaneous activation of an unfertilized mature egg followed by normal divisions and subsequent embryonic development What is fragmentation? - Answer Asexual reproduction in which a body part is lost and then regenerates into a new organism What is the concentration of Fe2+ at equilibrium if the Ksp of FeS equals 6.0 x 10-19 in an aqueous solution of pure water? - Answer Find the balanced chemical equation:

FeS (s)àFe2+ (aq) + S2- (aq) Find the equilibrium expression: Ksp = [Fe2+][S2-] Solve: 6.0 x 10-19 = [Fe2+][S2-] 6.0 x 10-19 = x x = sqrt(6.0 x 10-19) Recall that a propagation step is any step that has at least one radical on both sides of the equation. Thus we should look for a step in which there is at least one radical on both sides of the equation. - Answer thin layer chromatography? what has the highest Rf? - Answer a separation technique that involves the separation of small molecules as they move through a silica gel;;;;;; the ones with only carbon and hydrogens What is the Rf value? what is a Grignard reagent? - Answer The movement of a substance during chromatography, relative to the movement of the solvent, is measured by calculating its Rf (retardation factor);;;;; RMgBr with H3O+, makes esters into tertiary alcohols when you have an alkyne, what is the difference between H2,Lindlar and Na,NH3 reactions? what is the result of bromination of toluene? - Answer H2,Lindlar forms a cis alkene Na,NH3 forms a trans alkene Br2, FeBr3 makes p-bromotoluene what does NaBH4,EtOH do to aldehydes? what does PBr3 do to primary alcohols? - Answer makes them to primary alcohols;;;;; takes off the alcohol and switches it with Br If 2n = 8, how many chromosomes are present during anaphase? - Answer 16 Which of the following lack a true coelom? A. flatworms B. Annelids C. Echinodermis D. CHordates

E. Mollusks - Answer A. flatworms (its part of platyhelminths) A coelom is a cavity lined by an epithelium derived from mesoderm. Mollusks have a reduced, but still true, coelom. A flatworm(also known as planarian) is an acoelomate because it does not have a coelom within its mesoderm layer. What is the role of calcium in muscle cells? - Answer To expose the binding sites on actin filaments During a muscle contraction, a neuron releases acetylcholine which triggers an action potential on the muscle cell. This signal is propagated by T tubules and releases Ca2+ from the sarcoplasmic reticulum and initiates contraction of the muscle cell. The calcium binds to actin filaments called troponin, which allows it to change its shape and expose binding sites for myosin. The myosin binds to the actin by using ATP and shortens, creating a contraction what is the difference between allopatric speciation and sympatric speciation? - Answer Allopatric speciation describes the formation of a new species as a result of a population being divided by a geographic barrier;;;;; Sympatric speciation describes the formation of new species without the presence of a geographic barrier like unbalanced alleles and natural selection A researcher extracts a biomolecule from a cell and finds its molecular makeup is comprised of a large amount of nitrogen, no sulfur, and is found in both the cytoplasm and the nucleus. Which of the following is most likely the biomolecule the researcher extracted? A. Glycogen B. Actin C. DNA D. RNA E. Cholesterol - Answer D RNA DNA only appears in Nucleus whereas RNA appeas in both nucleus and cytoplasm What is the fundamental niche of an organism? - Answer The environmental conditions where an organism can potentially live NOT the habitat oranism occupy in the enviroment All of the following are connective tissues except for one, which one is the exception? A. adipose B. Neurons C. Cartilage D. Bones E. Blood - Answer B. Neurons

Remember: Kingdom Phylum Class Order Family Genus Species What does the subcutaneous layer do? - Answer stores fats, insulates and cushions the body, and regulates temperature After the successful implantation of a developing embryo into the uterus, all of the following occur EXCEPT one. Which one is the EXCEPTION? A. Increase in follicle stimulating hormone (FSH) and luteinizing hormone (LH) B. Increase in human chorionic gonadotropin (HCG) C. Miantaned high levels of estrogen D. Maintained high levels of progesterone E. Maintenance of the corpus luteum - Answer A. After the successful implantation of a developing embryo, the corpus luteum is maintained (it does not degenerate). The corpus luteum produces estrogen and progesterone. With the continued presence of estrogen and progesterone, there is negative inhibition on GnRH. This causes FSH and LH levels to decrease, not increase. Which of the following statements accurately describes cytokinesis in mammals? A. Molecular chaperones pull each cell to opposing ends. B. Vesicles migrate and fuse to form a cell plate. C. Microfilaments encircle the center of the cell and shorten. D. Microtubules pull apart the homologous chromosomes. - Answer Microfilaments encicle the center of the cell and shorten During cytokinesis of animal cells, actin and myosin microfilaments encircle the center of the cell and shorten, pulling the plasma membrane towards the center of the cell, eventually resulting in two separate cells. what does a increase in calcitonin lead to? - Answer stimulate osteoblat activity Assuming independent assortment, how many different gametes can be produced from the genotype AaBbCc? - Answer ABC, ABc, AbC, Abc, aBC, aBc, abC, abc We have 2 alleles and 3 genes, so 2^3 = 8 combinations. A scientist wishes to create bacterial colonies on an agar plate for observation of growth. Unfortunately, directly adding bacteria from the original culture results in too many bacterial

colonies to count. In order to create a solution of proper bacterial concentration for observation, the scientist performs a three-step 1:100 serial dilution of the original bacterial culture. What is the dilution factor of the final solution? - Answer 10^ A color blind man without hemophilia (both X-linked traits) marries a woman who is a carrier for both traits. What is the probability they will have a son with both color blindness and hemophilia? Hemophilia and color blindness are unlinked genes. - Answer 1/2 x 1/2 x 1/2 = 1/ boy, hemophilia, and colorblindness An animal cell was lysed, placed in a test tube, and centrifuged. Which organelle would pellet from the centrifuge first? A. Ribosome B. Lysosome C. Mitochondria D. Golgi complex E. Nucleus - Answer E. Nucleus Centrifugation works by spinning a tube of components at high velocities to create a force. The heavier a component is, the faster it will pellet out of the solution. The nucleus is the largest and most dense organelle in the cell and will pellet first A population of sheep is in Hardy-Weinberg equilibrium. The trait for black wool is dominant, and the trait for white wool is recessive. Out of 100 sheep, 84 were found to have black wool. How many sheep are heterozygous? - Answer p + q = 1 p^2 + 2pq + q^2 = 1 .16 = q^ so sqrt 0.16 = 0. q - 0.4 and p must be 0. 2(0.4)(0.6) = 0. so 48 sheep are heterozygous During embryonic development, a hollow sphere of cells is called a - Answer blastula What is pleiotropy? - Answer the production by a single gene of two or more apparently unrelated effects. (color of fur and shape of ears) what is epistasis? - Answer Epistasis describes when one gene affects the phenotypic expression of a second gene. What does SDS do? - Answer It denatures proteins and provides net negative charge. Smallest polypeptide runs fastest.

A frameshift mutation is one which causes the reading frame of codons to be shifted due to the insertion or deletion of a nucleotide. In a nonsense mutation, as a result of a nucleotide change, an existing codon is changed to a stop codon, resulting in the protein being cut short prematurely. In a missense mutation, a codon is changed in a way that results in a different amino acid being used in place of the original one In an inversion mutation, a segment of a chromosome is rearranged in the reverse of its original orientation. - Answer What is the function of restriction enzymes in recombinant DNA technology? - Answer A restriction enzyme (or restriction endonuclease) is used in recombinant DNA technology to cut up DNA at specific sequences, usually in a staggered manner. Examples of restriction enzymes include EcoRI, TaqI, and BamHI. hich of the following describes the evolution of fish, from earliest to latest ancestor? A. Jawless fish - > Lobe-finned fish - > Cartilaginous fish B. Cartilaginous fish - > Lobe-finned fish - > Jawless fish C. Bony fish - > Cartilaginous fish - > Lobe-finned fish D. Jawless fish - > Cartilaginous fish - > Lobe-finned fish E. Cartilaginous fish - > Jawless fish - > Bony fish - Answer D. Jawless fish - > Cartilaginous fish - > Lobe-finned fish The first fish to evolve did not have jaws and looked like eels. Afterwards, cartilaginous fish (such as sharks) evolved. Lastly, lobe-finned fish developed, from which terrestrial organisms developed. For the purpose of the DAT, it is helpful to know other significant steps in the evolution of chordates. These steps in order of evolution include formation of the following structures: where were notochords first seen? what about a head? what about a vertebral column? what about jaws and mineralized skeleton? what about lungs/lung derivatives? - Answer in Lancelets and tunicates;;;;;; in Hagfish;;;;;; in Jawless fish like lampreys;;;;;; chondro notochord (first seen in lancelets and tunicates) - > head (first seen in hagfish) - > vertebral column (first seen in jawless fish (also known as Class Agnatha, e.g. lampreys) - > jaw and mineralized skeleton (first seen in chondrichthyes, e.g. sharks) - > lungs/lung derivatives (first seen in ray-finned fish) - > lobed fins - > limbs with digits (amphibians) - > amniotic eggs (reptiles)

• production of milk (mammals). Which part of the brain monitors the body's temperature?

A. Hypothalamus B. Pons C. Medulla D. Cerebral cortex E. Cerebellum - Answer A. Hypothalmus What does the hypothalamus control? - Answer regulates homeostasis. regulates thirst, hunger, body temp, water balance, and blood pressure and links nervous system to endocrine system What does the pons control? - Answer Relays messages from cerebellum to forebrain and controls sleep and dreaming what does the medulla oblongata control? - Answer heart rate, blood pressure, breathing, swallowing, vomiting What does the cerebral cortex control? - Answer Outer layer of the cerebrum and contains the brains (frontal, temporal, occipital and parietal) and is the place of higher level thinking what does the cerebellum control? - Answer Balance and coordination What two structures form the placenta in mammals? what does the allantois develop into? what about the yolk sac? - Answer the chorion and endometrium which is the site of nutrient and gas exchange between mother and embryo;;;;; the umbilical cord and passage of nutrients and waste;;;;;; location of first RBC formation Animals typically have three types of movement. what are they and their definitions? - Answer Kinesis- animal moves in random directions and will be slow in favorable enviroments, but spped up in unfavorable enviroments Taxis- animal moves in a specific direction after reciving a stimulus, animal moves toward or away from stimulus (phototaxis is a type of taxis like flies being attracted to lightbulbs at night)(positive taxis is where animals moves against current toward food, negative taxis is when animal moves against current to get away from predator) Migration what is the difference between Diastole and Systole? - Answer in diastole, ventrilcles are filling/relaxed and AV valves are open which Semilunar valves (leading to arteries) are closed to prevent backflow. During Systole, AV valves close and semilunar valves open, ventrilces also contract and push blood out into arteries

What is the process of cloning of an animal? what is totipotent? What is Pluripotent? - Answer taking a somatic cell from an animal and producing a genetic copy from that cell with no genetic variation. you would have to Revert a somatic cell into a totipotent state a single cell with the ability to divide and produce an entire organism and give rise to any human cell. They are capable of producing extraembryonic membranes A stem cell that can differentiate into any 3 germ layers (endoderm, mesoderm, ectoderm) but they cannot develop an entire organism because the cannot develop extraembryonic tissues such as placenta Which of the following techniques would best allow a scientist to determine which genes are and are not expressed in a cell? A. ELISA B. Gel Electrophoresis C. Karyotyping D. PCR E. DNA microarray - Answer E. DNA microarray What is a DNA microarray? - Answer determines which genes are expressed and which genes are not expressed in a sample. (useful in cancer research) What is the ELISA test? - Answer test that diagnoses viruses (Enzyme-linked immunosorbent assay) in which you determine if a specific antigen exists What is gel electrophoresis? - Answer a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size and charge. shorter macromolecules will move faster and travel farther What is karyotyping? - Answer used to count the number of chromosoems in a cell. (used in diagnosis of trisomy diseases. what is PCR? - Answer used to amplify the amount of DNA available, usually as an intermediate step of other genetic techniques. What is negative feedback? - Answer Body REVERSES an original stimulus to regain balance what is the name of the shaft of the long bone? what is it made of? what is the epiphysis? what is the metaphysis - Answer diaphysis, of compact bone;;;;;; the rounded end of a long bone;;;;;;

wider portion of a long bone situated near epiphysis where majority of growth happens during puberty What is the periosteum? what does it provide? - Answer a dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints.. ;;;; nourishment and sensation to bones What is the medullary cavity? - Answer central cavity of bone shafts and contains yellow bone marrow. Here, we are looking for two structures that target the same organ with different hormones. The posterior pituitary releases ADH, which allows the kidneys to reabsorb more water. The adrenal cortex releases mineralocorticoids, such as aldosterone, which affects the kidney to increase salt reabsorption (which in turn increases water absorption as well due to changes in osmolarity). what is Binary fission - Answer Binary fission is a form of asexual reproduction in prokaryotes and some organelles within eukaryotes (mitochondria and chloroplasts). The DNA is duplicated and then the two copies migrate to opposite sides of the cell, and the cell then splits into two. The consequence of this is that all the bacteria and progeny are genetically identical. what will heat shocking a bacteria with CaCl2 cause them to do? - Answer force bacteria to uptake plasmids and incorporate them into their genome, this is a form of transformation If a human cell has 46 chromosomes at the beginning of meiosis, then at the end of meiosis I each cell would have A. 23 chromatids. B. 46 chromatids. C. 46 chromosomes. D. 92 chromatids. E. 92 chromosomes. - Answer B. 46 chromatids or 23 chromosomes Because meiosis 1 will take a diploid cell and produce 2 haploid cells. this means that chromosome number will decrease to 23 chromosomes for each daughter cell. so 46 choromatds will be present for each daughter cell what is the law of Parsimony? - Answer The law of parsimony, or Occam's Razor, says that when choosing between competing hypotheses, the one that makes the least amount of assumptions is the most preferred.

When developing phylogenetic trees, the tree that explains the evolution of organisms with the least amount of assumptions is most likely the correct one. what are the products of the light-dependent reactions in photosynthesis? where do they take place? what are the reactants in the light-dependent reactions? What is the difference between cyclic photophosphorylation and noncyclic photophosphorylation? - Answer O2, NADPH, and ATP;;;;; in the thylakoid membranes of chloroplast;;;;;; CO2 and rubisco;;;;; cyclic produces ATP and noncyclic produces NADPH What is needed to make the final products (glucose NADP+, and ADP) in photosynthesis? - Answer the products O2, NADPH, and ATP of light-dependent reactions, as well as the other reactants CO2 and rubisco A grandmother and her granddaughter are the only two members in a family to have a genetically inherited disease. Neither parent of the granddaughter has the disease. The disease is probably inherited as a(n) A. Y-linked dominant disease B. autosomal dominant disease C. autosomal recessive disease D. X-linked dominant disease E. X-linked recessive disease - Answer C. autosomal recessive disease What is a tetrad? If 2n=46, how many tetrads are present during metaphase I? - Answer A pair of homologous chromosomes or a group of 4 sister chromatids during Prophase I. 23 An experiment is designed to track the movement of DNA within a cell. Which radioactive isotope would be the most useful to mark a nucleic acid? A. 32P B. 35S C. 15N D. 13C E. 15O why is it the best one? - Answer A. 32P

because DNA-contains a phosphate backbone making the radioactive isotope 32P ideal for tracking DNA What happend in Hershey and chase experiment and how did they prove that DNA was the genetic material of bacteriophages? - Answer by incorporating 32P into phage DNA and observing that the radioactive phosphorus (as part of DNA) was transferred inside infected bacterial cells (while 35S, incorporated in the protein coat of the bacteriophage, remained in the liquid surrounding cells). What type of cell junction is most common between digestive tract cells? A. Desmosomes B. Gap junctions C. Tight junctions D. Plasmodesmata E. Anchor junctions - Answer C. Tight junctions What do tight junctions do? - Answer form a water tight seal between cells that can block water, ions, and other molecules from moving past the cells What do desmosomes do? what type of junction are they considered? - Answer connects two cells together by linking their cytoskeleton. They are organized for mechanical strength, not an impermeable barrier (often seen in skin cella).;;;;;; Anchoring junction what are the 2 types of communicating junctions and what is the difference between the two? - Answer Passageway that allows for the transfer of chemical or electrical signals Gap junction (animal) Plasmodesmata (plants) what are the 3 types of anchoring junctions? - Answer desmosomes, hemidesmosomes, adherens hemidesmosomes- cell to extracellular matrix adherens- cell to cell adhesion or cell to extracellular matrix In the kidney system, blood enters from an afferent arteriole into the glomerulus, where pressure forces water and solutes through the capillary walls into the Bowman's capsule, like a sieve. Small particles can be pushed through the capillary walls, but red blood cells and proteins cannot pass through and remain in the blood. The filtrate in the Bowman's capsule will then travel through the nephron, where the majority of salts, water, and glucose will be reabsorbed.

• Answer a surge of which hormone causes ovulation in females? what is the difference between FSH and LH? - Answer LH;;;;;

FSH will stimulate the development of the follicle and oocyte, and the follicle will secrete estrogen. Positive feedback from estrogen will cause a surge of LH, which will cause ovulation. The follicle now becomes a corpus luteum and develops from the help of LH, and will secrete both estrogen and progesterone. High levels of estrogen and progesterone will thicken the endometrium in the uterus for implantation of a fertilized egg. However, the high levels of estrogen will cause the hypothalamus to stop producing GnRH, which will stop the anterior pituitary from releasing FSH and LH. Now, if the corpus luteum is unfertilized, then it will deteriorate, as the body is no longer supporting it, and menstruation occurs. If the egg is fertilized, it will implant into the endometrium and produce HCG (human chorionic gonadotropin) to support the corpus luteum, which will continue to secrete estrogen and progesterone to maintain the endometrium, and pregnancy will continue. The endosymbiotic theory states that eukaryotic cells originated from a mutualistic relationship between two prokaryotes. Some evidence that points towards this includes:

1. Mitochondria and chloroplasts both have their own DNA separate from the rest of the cell, and this DNA is circular and without any proteins, much like prokaryotes.
2. Mitochondria and chloroplasts have different ribosomes that are more similar to prokaryotes than eukaryotes.
3. Mitochondria and chloroplasts reproduce independently of the host cell by a process that is similar to binary fission, used by prokaryotes.
4. Mitochondria and chloroplasts have a double membrane, which could have resulted from one prokaryote engulfing the other prokaryote in an endocytosis fashion, forming a vesicle.
5. The thylakoid membranes of chloroplasts resemble the photosynthetic membranes of cyanobacteria, which are autotrophic bacteria. - Answer what are examples of totipotent cells? what are examples of pluripotent stem cells? - Answer zygote and blastomere or morula;;;;;; inner cell mass cells In the Miller-Urey experiment that simulated conditions of the early Earth, all of the following molecules were included EXCEPT one. Which one is the EXCEPTION? A. Ammonia (NH3) B. Water (H2O) C. Hydrogen (H2) D. Oxygen (O2) E. Methane (CH4) - Answer D. Oxygen Miller-Urey Summary The Miller-Urey experiment was designed to test the "organic soup theory" originally put forward by Oparin & Haldane. Oparin and Haldane put forth the theory

that the origin of the Earth's environment was a reducing environment (without O2), allowing for the formation of complex organic molecules from simpler ones Which of the following occurs during embryonic cleavage from zygote to morula? A. Decrease in morula size B. Decrease in blastomere size C. Differentiation of blastomeres to pluripotent cells D. Formation of the blastocyst E. Invagination into zygote to form the neural tube - Answer B. Decrease in blastomere size During cleavage of the zygote, each new blastomere becomes increasingly smaller. However, the size of the entire zygote/morula does not change. Each division gives less cytoplasm to the daughter cell in preparation for cell differentiation. Which of the following would increase the expression of a eukaryotic gene? A. Histone acetylation B. RNA interference C. DNA methylation D. Heterochromatin packaging E. Repressor proteins - Answer A. Histone acetylation DNA is coiled around histones in eukaryotes and some Archaea. The combination of DNA and histones is called a nucleosome. Recall that DNA has a slight negative charge. If we add acetyl groups to the histones, we would make the histone groups more negative, and they would repel the negatively charged DNA to make the DNA more accessible, thus there will be more transcription and more expression of the gene. What is the difference between heterochromatin and euchromatin? - Answer Heterochromatin is tightly packed DNA that consists of genes not transcribed. On the other hand, euchromatin consists of more "open" DNA that is transcribed and expressed. What is DNA methylation? - Answer DNA methylation is a method of gene suppression that is especially important for the field of epigenetics. During methylation, some nucleic acids have their hydrogen removed and replaced with a methyl group. This leads to gene suppression through preventing transcription factor from binding and by recruiting methyl-binding proteins (MBDs) that cause a cascade that results in suppression

A population of fish is in Hardy-Weinberg equilibrium. Red-colored scales are a dominant trait and blue-colored scales are a recessive trait. In the population, 36% of the fish display red- colored scales. What percent of the population in the next generation is expected to be homozygous dominant? - Answer 100-36 = 64 .64 = q^ so squrt .64 = squart q^ 0.8 = q so 0.2 = q and .20^ = .04 which is p^ ans: 0.04 Which of the following is the location for the maturation and storage of sperm? A. Seminiferous tubules B. Vas deferens C. Epididymis D. Sertoli cells E. Oviduct - Answer C. Epididymis Spermatogenesis begins at puberty and starts with spermatogonia cells in the seminiferous tubules. Spermatogonia divide by mitosis to produce primary spermatocytes, which undergo meiosis I and II. Unlike females, who only keep one of the 4 possible daughter cells, males keep and develop all 4 daughter cells. Sertoli cells provide nourishment to the sperm while they mature. The sperm finally complete their maturation and are stored in the epididymis. The oviduct is a female structure that transports oocytes to the uterus. Genes A, B, and C are unlinked and autosomal. What is the probability that an individual with the genotype AaBbCC will be born from a cross between AaBbCc × AaBbCc? A. 1/ B. 1/ C. 1/ D. 1/ E. 1/2 - Answer B 1/ We want the genotype AaBbCC. So there is a 1/2 chance of getting Aa from the cross between gene A, a 1/2 chance of getting Bb from gene B, and a 1/4 chance to get CC from gene C. Multiplying together, we find 1/2 × 1/2 × 1/4 = 1/16. Sebaceous glands can be found in all of the following areas EXCEPT for one. Which one is the EXCEPTION? A. Eyelids B. Palms C. Scalp D. Underarms E. Earlobes - Answer B. palms

All of the following are methods plants use to reduce water loss EXCEPT for one. Which one is the EXCEPTION? A. Trichromes and hairs on the leaves B. Needle-like leaf structure C. Thick waxy cuticles D. Reflection of green light E. Guard cells in stomata - Answer D. Reflection of green light Plants have evolved many different mechanisms to decrease the amount of water they lose to transpiration. Among them include growing little "hairs" on their leaves to retain more moisture and a thin needle-like leaf structure. Christmas trees and other conifers have needle leaves as an adaptation to growing in a dry environment. Desert plants have thick waxy cuticles as a way to minimize the amount of moisture the plant transpires, and guard cells in the stomata close off the holes in the leaves when activated. The reflection of green light is irrelevant to reducing water loss. A specific X-linked recessive allele is lethal. Males that inherit the recessive allele and females that are homozygous recessive will abort before birth. What is the probability that a heterozygous mother will give birth to a child with only one copy of the recessive allele? A. 0 B. 1/ C. 1/ D. 1/ E. 1 - Answer C. 1/ From this square, we see four possible genotypes, but the child with the genotype XaY will not be born! Thus, there are only 3 possible phenotypes, XAXA, XAY, and XAXa. Only one of these has one copy of the allele Xa, thus there is a 1/3 probability that a child will be born with only one copy of the recessive allele. A scientist thinks she has discovered a new species of beetle. Which of the following would help determine if the beetle is a new biological species or not? A. Compare proteins from the beetle's eggs to other known species B. Compare physical differences between the new beetle and known beetles C. Sequence the DNA of the new beetle D. Attempt to interbreed the beetle with other known species, and check the viability of its offspring

E. Compare the beetle's behavioral patterns - Answer D. Attempt to interbreed the beetle with other known species, and check the viability of its offspring Defining a species can be tricky, and there are several different species concepts that define what a species is. The hallmark of a new species according to the biological species concept is the inability to interbreed. If the beetle can breed with other known beetles, then it is not a new species. However, if it is unable to interbreed, then this would be a new species of beetle. For offspring to be considered viable, it must be able to live to reach reproductive maturity and be able to produce its own offspring. Sequencing the DNA could find some similarities, but ultimately this does not define a new species. Physical differences between individuals can vary vastly inside a group of species, so this is not a useful way to distinguish between different species. What is the function of Haversian canals in long bones? A. Provide flexibility to bones B. Supply nutrients and nerve function in compact bone C. Form dense lamellae to support the bone D. Provide space for red bone marrow growth in cancellous bone E. Surround and protect the shaft of the bone - Answer B. Supply nutrients and nerve function in compact bone A long bone is made of dense compact bone (cortical bone) on the outside and cancellous bone on the inside (less dense bone). The dense compact bone still needs nutrients and nerve function, and Haversian canals provide this function by having little tubes running parallel to the axis of the long bone. The Haversian canals house blood vessels, nerves, and lymphatic vessels. Cancellous bone, also known as spongy bone, is less dense and houses red bone marrow and yellow bone marrow All of the following events occur during photosynthesis EXCEPT for one. Which one is the EXCEPTION? A. G3P is produced in the stroma. B. The pH inside of the thylakoid is decreased. C. Carbon dioxide is more concentrated in the stroma. D. The inner membrane of the chloroplast absorbs light. E. Photolysis of water provides the source of electrons. - Answer D. The inner membrane of the chloroplast absorbs light. The thylakoid membrane contains the chlorophyll molecules that absorb light. The inner membrane does not have a large role in photosynthesis. Most of photosynthesis occurs in the stroma and thylakoid. Water undergoes photolysis inside of the thylakoid to provide electrons for the chlorophyll molecules to excite with photons of light

All of the following are secondary messengers used in signal transduction EXCEPT one. Which one is the EXCEPTION? A. cAMP B. DAG C. IP D. Ca2+ E. Epinephrine - Answer E. Epinephrine Secondary messengers relay signals from receptors on the surface of the cell to target molecules inside of the cell. They are especially useful in signal transduction to help amplify a signal quickly.cAMP, cGMP, DAG, IP3, and Ca2+ are all common secondary messengers. Hormones, like epinephrine, are often just activators of the secondary messenger system. In infected cells, what do MHC proteins produce? - Answer Display 'nonself' markers on the plasma membrane All of the following are proteins EXCEPT for one. Which one is the EXCEPTION? A. Dynein B. Clathrin C. Kinesin D. Keratin E. Chitin - Answer E. Chitin what id Dynein? what is Clathrin? what is Kinesin? - Answer a motor protein that uses ATP to transport substances within a cell via movement on microtubules toward center of cell;;;;;; protein that coats vesicles and plays a role in formation of them.;;;;; same as Dynein only sends substances toward periphery of cell What is chitin? - Answer a polymer of beta glucose molecules All of the following are associated with individuals in a population with a r-selected life history strategy EXCEPT for one. Which one is the EXCEPTION? A. They exhibit rapid growth (J-shaped curve). B. They produce many offspring. C. They receive little or no parental care. D. They have a long life span. E. They reach maturity quickly. - Answer D. They have a long life span.

Life-history strategies include K-selected species and r-selected species. r-selected species are exemplified by insects and grasses. These individuals reproduce quickly to take advantage of an opportunity. Their offspring are often small, mature quickly, require little parental care, and die quickly (therefore Choice [D] is false). In contrast, humans exemplify K-selected species. The population size remains relatively constant (at carrying capacity, K). Humans produce a few offspring of larger size and require a significant amount of parental care until they mature. A researcher wants to insert a eukaryotic gene, which currently contains introns, into a prokaryote by use of a plasmid to produce synthetic insulin. All of the following are steps that should be included in the procedure EXCEPT for one. Which one is the EXCEPTION? A. Use reverse transcriptase to create the cDNA of the eukaryotic gene B. Use a restriction enzyme that produces sticky ends C. Methylate the plasmid DNA to change its configuration D. Use ligase to seal the eukaryotic DNA into the plasmid E. Place the cell in a medium of CaCl2 and heat - Answer C. Methylate the plasmid DNA to change its configuration All of these are steps in genetic engineering except for Choice [C]. Methylation is often used to differentiate between original and new strands in DNA replication. From which structure does the spinal cord develop? A. Archenteron B. Notochord C. Blastodisc D. Neural tube E. Allantois - Answer D. Neural tube The spinal cord is part of the central nervous system (CNS). The central nervous system is derived from the ectoderm. Above the notochord, a layer of cells begin to form a neural groove, which later develops into a neural tube. This neural tube will develop into the spinal cord and brain. The archenteron is a center cavity formed during embryonic development (specifically during the phase of gastrulation) that is completely surrounded by endoderm cells which eventually gives rise to the gut/digestive system; The product of indeterminate cleavage can also be named a(n) A. animal pole. B. totipotent cell. C. pluripotent cell. D. vegetal pole. E. multipotent cell. - Answer B. totipotent cell

Two types of cleavage can occur. Indeterminate cleavage produces cells that can individually complete normal development (are totipotent). This is how identical twins are born. Determinate cleavage produces cells that have a decided fate and are no longer totipotent. what is cdna? - Answer Complementary strand of DNA synthesized from an RNA template by the enzyme reverse transcriptase. Which technique would a researcher use to observe the migration of chromosomes during mitosis? A. Scanning electron microscopy B. Transmission electron microscopy C. Fluorescence microscopy D. Stereo microscope - Answer C. Fluorescence microscopy Plants release most of their water into the hydrological cycle by A. decomposition. B. respiration. C. transpiration. D. assimilation. E. photosynthesis. - Answer C. transpiration. Transpiration is the evaporation of water vapor from air spaces found on the surfaces of plants. Which of the following factors supports the structure of beta-pleated sheets in proteins? A. Disulfide bonds B. Hydrogen bonding C. Hydrophobic effect D. Ionic bonding E. Covalent bonding - Answer B. Hydrogen bonding A protein has four levels of structure. The secondary structure results in a three dimensional protein with either alpha helices or beta-pleated sheets, depending on the types of amino acids present. These structures occur due to hydrogen bonding between the amino and carboxyl

groups of adjacent amino acids. The tertiary structure of proteins is supported by all of the factors listed. The quaternary structure occurs when separate polypeptide chains come together and interact to form a larger protein held in place by the above factors as well.A classic example is hemoglobin, which consists of four different polypeptide chains held in place by hydrogen bonding, disulfide bridges, and hydrophobic effects. If 2n=46, how many chromosomes would you expect to find in anaphase? A. 12 chromosomes B. 23 chromosomes C. 46 chromosomes D. 69 chromosomes E. 92 chromosomes - Answer E. 92 chromosomes During mitosis, 46 chromosomes will line up on the metaphase plate. Each chromosome will have two duplicate chromatids, for a total of 92 chromatids. When these chromosomes split during anaphase, we will still have 92 chromatids, but we will also have 92 chromosomes, since each chromatid is now separate. Once the two daughter cells separate each will have 46 chromosomes (and 46 chromatids). Which of the following muscles attach to the atrioventricular valves and contract to prevent prolapse of these valves on systole? A. Extraocular muscles B. Papillary muscles C. Sphincter pupillae muscles D. Ciliary muscles E. Reticular muscles - Answer B. Papillary muscles Sphnicter pupillae muscles is a muscle in the eye Which area of the eye has the highest density of photoreceptors? A. Sclera B. Optic nerve C. Fovea D. Lens E. Cornea - Answer C. Fovea The fovea is the area of the eye responsible for our sharp central vision, like you are using now. Nearly 50% of all the optic nerves travel to this region since it has so many photoreceptors!

Bryophytes are non-vascular and disperse spores, but gametophytes are the dominant generation. Angiosperms are vascular plants with a sporophyte dominant generation that use seeds as their method of dispersal. Gymnosperms are vascular plants that disperse seeds, however their dominant generation is sporophyte. Monocots do not have a taproot (main root) present - their root system is fibrous. Monocots have one cotyledon, parallel veins, scattered vascular tissue, and their floral organs are usually in multiples of three. Dicots possess a taproot (main root). Dicots have two cotyledons, netlike veins, vascular tissue arranged in a ring, and their floral organs are usually in multiples of four or five. - Answer Which of the following plant categories is correctly matched with its characteristics? A. Bryophytes: non-vascular; sporophyte dominant generation; spore dispersal B. Angiosperms: vascular; sporophyte dominant generation; seed dispersal C. Gymnosperms: vascular; gametophyte dominant generation; seed dispersal D. Monocots: one cotyledon, scattered vascular tissue, taproot present E. Dicots: two cotyledons, netlike veins, no taproot present - Answer B. Angiosperms: vascular; sporophyte dominant generation; seed dispersal Colchicine is a drug used for the treatment of gout. Its mechanism of action inhibits microtubule polymerization by binding to tubulin. Consuming this drug before or during pregnancy would most likely have an adverse effect on all of the following cellular activities EXCEPT for one. Which one is the EXCEPTION? A. Embryonic cell cleavage B. Mitotic spindle formation C. Egg transportation into the fallopian tube D. Cleavage furrow formation E. Fertilization - Answer D. Cleavage furrow formation Remember cleavage is rapid division of cells which uses microtublules What is a feature of only Gram negative bacteria, and is not found in Gram positive bacteria? Only Gram negative bacteria A. maintain both an inner and outer cellular membrane. B. stain dark violet when Gram stained. C.

contain a thick peptidoglycan layer. D. are considered prokaryotes. E. lack a nuclear membrane. - Answer A. maintain both an inner and outer cellular membrane. Remember gram positive bacteria have thick peptidoglycan so they stain dark violet. Gram negative have thin peptidoglycan with an outer membrane in addition to an inner membrane Which of the following characteristics can be true of fungi? A. Fungi can mutualistically associate with yeast to form a lichen. B. Fungi can have cell walls containing cellulose and peptidoglycans. C. Fungi can be phototrophic, using sunlight to synthesize nutritional molecules. D. Fungi can reproduce asexually via fragmentation, budding, or binary fission. E. Fungi can alternate through a life cycle of haploid and diploid stages. - Answer E. Fungi can alternate through a life cycle of haploid and diploid stages. Which of the following is involved in the monitoring and control of respiration? A. Monitoring of blood [H+] by central chemoreceptors of the medulla B. Increased production of surfactant by the alveoli in response to rise of blood CO2 C. Signaling from the medulla to the diaphragm to alter the rate and depth of ventilation D. Monitoring of cerebrospinal fluid by peripheral chemoreceptors in the carotid bodies E. Increasing respiratory rate in response to a sharp rise in blood pH - Answer C. Signaling from the medulla to the diaphragm to alter the rate and depth of ventilation Which of the following is a structural feature present only in the phylum Porifera? A. Spicule B. Cnidocyte C. Tentacles D. Radula E. Exoskeleton - Answer A. Spicule The spicule is a skeletal needle structure found in the basic skeleton of Porifera. Cnidocytes are the stinging cells of Cnidaria. Tentacles are a feature of Cnidaria and Mollusca.

The radula is a 'mini tooth' found in Mollusca. Exoskeletons are external skeletons found in Mollusca and Arthropoda A patient is admitted to the ER after being stabbed several times. The doctor suspects epinephrine and norepinephrine production have been compromised because the patient has decreased blood glucose levels and heart rate. Which organ requires surgical repair? A. The adrenal cortex B. The thalamus C. The adrenal medulla D. The hypothalamus E. The thymus - Answer C. The adrenal medulla what does the adrenal cortex produce? what does the thalamus serve for? what does the thymus secrete? - Answer corticosteroids, especially cortisol and also androgens;;;;; relay center for nervous signals to the cerebral cortex;;;;; where T cell leukocytes mature What does the adrenal medulla produce? - Answer catecholamines like epinphrine and norepinephrine Compared to an embryo that develops entirely inside the body, which of the following is likely to be true of the embryo of an animal developing in an egg outside of the mother's body? A. Not require oxygen B. Have more abundant yolk C. Be classified as a placental animal D. Have a more developed umbilical cord E. Not possess a chorion - Answer B. Have more abundant yolk Which of the scenarios best represents the actions of a bacterial facultative anaerobe in the presence of oxygen? A. The cell undergoes substrate level phosphorylation to produce all of its ATP. B. The cell releases carbon during Krebs cycle as CO2 molecules. C. The cell generates ATP across its mitochondrial membrane. D. The cell regenerates NADH through fermentation.

E.

The cell will die in the presence of oxygen. - Answer B. The cell releases carbon during Krebs cycle as CO2 molecules. Which of the following eukaryotic organisms would contain coenocyte cells? A. A bacterium B. A flower C. A fungus D. A human E. A frog - Answer C. A fungus where are coenocyte seen and what are they? - Answer in fungus and protist.. its a large multinucleate cell which occurs when a fungal or Protista cell divides its nucleus but does not undergo cellular division (cytokinesis). what are the two main categories of fungi and what are some differences? what are all the hyphae together known as? - Answer Nonfilamentous fungi- do not produce hyphae (common example is yeast) Filamentous fungi- such as molds, their multicellular and multinucleate because they form hyphae mycelium When you see a mushroom in the forest, the mushroom top only represents the spore. Many spores in a patch of mushroom tops are all connected underground by hyphae. As the hyphae grows, a wall often forms inside it, separating the hyphae into different sections. These walls are known as septa. Fungi that produce these septa possess septate hyphae. If septa are not formed, the hyphae is one long, continuous tube of multinucleated cytoplasm. This is known as coenocytic hyphae. - Answer Bone replaces cartilage in endochondral ossification Which of the following is true of eukaryotic protein translation and its components? A. The start sequence AUG codes for the amino acid threonine. B. Folding of the translated protein is determined strictly by chaperone proteins. C. During elongation, amino acids are joined together via disulfide bonds. D. Aminoacyl-tRNA synthetase requires ATP for its function. E. The stop codons UGA, UAA, and UAG code for the amino acid serine. - Answer D.