biology

1. When protons move through ATP synthase and generate ATP, this is an example of… !a. Passive transport !b. Facilitated diffusion 2. When dividing cells are observed under the microscope, chromosomes first become visible during: d. The first half of M phase$ 3. Orange vs tortoise shell vs black is an X-linked trait. Heterozygotes (XX o )are tortoise shell, homozygotes are orange (X o X o ) or black (XX). A black female cat (XX) is crossed to an orange male (X o Y). What is the expected ratio of black males to black females? a. 1:0 $ 4. Which of the following statements about diffusion is FALSE? c. In diffusion, the overall flow of molecules is from areas of low concentration to high concentration$ 5. A protein that forms an ion channel across a membrane is most likely to be: b. A transmembrane protein$ 6. The “hydrogen hypothesis” for the origin of mitochondria differs from the “fermenting predator hypothesis” in a couple of ways. Which is NOT one of those ways: b. One states that the mitochondrion was once a bacterium, the other does not$ 7. Cell walls allow cells to: a. Avoid the explosive effects of pure water$ 8. Members of the domains archaea and bacteria d. are prokaryotes$ 9. How does the surface area to volume ratio (S/V) of a 1 mm cube compare to that of a 3 mm cube? d. The ratio decreases as the cube becomes larger$ 10. Oxygenic photosynthesis requires two different photoreaction centers because: b. Even with the energy of a photon to excite electrons, evolution has not developed a photosystem can simultaneously reduce NADP+ and oxidize water$ 11. A researcher discovers a mutant strain of Arabidopsis that carries a frameshift mutation in the 5’ coding region of the “B” gene required for floral organogenesis. Based on the ABC model (Figure 11), what phenotype would you predict for the flowers of this mutant? b. Sepal, sepal, carpel, carpel$ 12. A researcher transforms the pollen of wild-type Arabidopsis with a gene that encodes the “B” gene required for floral organogenesis (see Figure 11), but in this synthetic gene she has replaced the B gene’s promoter with the promoter that drives the “C” gene. The pollen is then used to fertilize a wild-type plant. Based on the ABC model and your understanding of promoters, you would predict the following phenotype in the flowers of the resulting transgenic offspring: d. Sepal, petal, Stamen, Stamen$ 13. The gene for the major chlorophyll-binding protein (antenna protein) is encoded by the nuclear genome, but the protein functions in chloroplasts. The synthesis (translation) of the protein takes place in the... d. cytoplasm$ 14. If the organism to which the cell in Figure 10 belongs is heterozygous for the W gene (genotype Ww), the following applies: !e. Both a and b are true$ 15.The cell displayed in Figure 10 is in the following stage: b. meiosis I$ 16. A eukaryotic chromosome is typically ________ and it is replicated ________ _______.: b. linear, from multiple origins$ 17. A gene is mutated, changing a codon from GGG (glycine) to GAG (glutamic acid). As a result, we'd predict that… a. the protein's primary structure will change, and its tertiary structure might change$ 18. Cyanide (CN - ) closely resembles molecular oxygen, and binds tightly to cytochrome C oxidase, the electron carrier that reduces O 2 during respiration. Brain cells cannot ferment glucose but have to respire to utilize glucose. Cyanide is deadly to brain cells because in its presence: !b. ATP cannot be synthesized from ADP !d. NAD + cannot be generated from NADH 19. Propane (C 3 H 8) is considered a nonpolar molecule because a. Carbon and Hydrogen have similar electronegativities$ 20. Green plants… !a. Perform respiration and photosynthesis !d. Have mitochondria and plastids 21. Which of these compounds would be the weakest electron acceptor? a. SO 4 - b. CO 2 $ c. H 2 S d. Fe 3+ e. NO 3 - 22. Which reaction would proceed, but provide the least free energy for the cell? You may want to check the redox tower provided. a. NADH + S o ____ > NAD + + H 2 S$ b. NADH + Ubiquinone ox ____ > NAD + + Ubiquinone red c. H 2 + S 4 O 6 2- ____ > S 2 O 3 2- d. NADH + NO 3- ____ > NO 2- + NAD + 23. Both fermentation and respiration share the metabolic pathway termed “glycolysis”. They also share… a. a step involving oxidation of pyruvate b. a step involving reduction of pyruvate c. oxidative phosphorylation of ATP d. oxidation of NADH via the ETC !e. none of the above$ 24. Very early in the Earth’s history, there was no O 2 in the atmosphere. For this reason… c. Electrons from respiration were delivered to a different terminal acceptor$ 25. Which of the carbon atoms below is most oxidized? a. CH 4 b. CH 3 OH c. CH 2 O d. CO 2 $ 27. A bacterial mRNA has the sequence: AAUUGGCCAUGC. Which of the following DNA sequences might be the gene that encodes this specific section of the RNA? !a. 5’ AATTGGCCATGC !c. 5’ GCATGGCCAATT 28. In cats, S (white paws) is dominant to s (no white).  T (tabby, stripes) is dominant to t (solid color, here black).  An SsTt cat (tabby with white paws) is crossed to an SStt cat (black, with white paws). S and T are unlinked genes.   What is the expected ratio of phenotypes in the next generation? e. 1 tabby with white paws : 1 black with white paws$ 29. An individual inherits a mutation in a gene associated with breast cancer. In which cells is this allele located? !e. All the cells of the individual.$ 30.For complete expression of the Lac operon two criteria must be met: the absence of glucose and the presence of lactose. The reason for this is: !a. All bacteria can use glucose, so it’s best to use this up first, before another bacterium does. !b. Glucose catabolism genes are expressed all the time anyway !c. It is a waste of energy to produce proteins that are not needed, therefore, they do not turn on 31. In E. coli , cAMP is a signal for a. a drop in the intracellular ATP levels$ 32. Leucine is an amino acid required for protein synthesis. How might the leucine biosynthetic operon be regulated? !c. Repressed by leucine, by having leucine activate a repressor !d. Repressed by leucine, by having leucine inactivate an activator 33. Male early hair loss is an X-linked recessive trait. It can also be observed in women, if they are homozygous for the recessive allele. A woman who is not is not experiencing early hair loss, but had a father who did carry this trait, marries man who does not carry this mutant allele. What is the probability that their son will exhibit the trait? b. 50%$ 34. The maternity plant produces plantlets (“babies”) along the edge of the leaf. Individual leaf cells divide and form somatic embryos, i.e. embryos that are not derived from zygotes. Each embryo develops into a plantlet that will fall off the leaf and grow next to the mother plant. The plant also forms seed from normal flowers, which can cross- or self-pollinate. The genotype of the "mother" plant at the "z" locus is Zz. The most likely set of genotypes of 12 plants produced from the leaf edge of this plant is: a. all Zz$ 35. The genotype of the "mother" maternity plant at the "z" locus is Zz. The most likely genotypes of 12 plants grown from the seeds of this self-pollinated plant are: c. 3 zz, 6 Zz, 3 ZZ$ 36. In the purine nucleotide biosynthetic pathway drawn in Figure 8, the numbers represent enzymes required for the synthesis of GMP and AMP. The biosynthetic pathway branches at IMP. This pathway is subject to allosteric feedback regulation. If the concentration of AMP is too high, and the concentration of GMP is too low, a good way to adjust the concentration would be to have: e. AMP act as a negative regulator of enzyme 5$ 37. What is the external source of electrons used to reduce NADP+ during oxygenic photosynthesis? c. They are extracted from water by photosystem II$ 38. In what intracellular compartment is ATP synthesized via oxidative phosphorylation? e. The mitochondrial matrix$ 39. The net movement of uncharged molecules across a membrane barrier from a lower concentration to a higher concentration can be best explained by which of the following? b. active transport$ 41. Which of the following statements comparing bacteria and eukaryotes is true? a. Eukaryotic cells have a nucleus surrounded by a nuclear membrane; bacterial cells don't.$ 42. Which of the following statements about viruses is FALSE ? a. Viruses have a nucleus but no cytoplasm$ 43. Using Figure 1, match the building block molecule depicted to the appropriate name. a. 1=phospholipid, 2= nucleotide, 3= monosaccharide, 4= amino acid, 5= fatty acid$ 44. In Figure 2, the four pictures represent cross sections of spherical structures composed of phospholipids. Which of these structures is most likely to form when a phospholipid is vigorously dispersed in water? a. a$ 45. Consider a short polar charged region and a short non-polar region in a long polypeptide chain. When dissolved in water, the polypeptide will most likely fold to form a protein in which: b. The polar region is exposed on its surface and the non-polar region is interior. $ 46. Consider the following chemical reaction: A + B -> C. In Figure 3, the dashed line represents the energetics of this reaction WITHOUT an enzyme. Which of the solid lines (a, b, c) in the diagram best represents the way the curve would look in the presence of an enzyme catalyst that increases the reaction rate? b. B$ 47. If the chemical reaction A + B <-> C is at equilibrium, which of the following statements is FALSE? c. The concentration of products will increase at a steady rate.$ 48. The reaction catalyzed by the enzyme hexokinase (Reaction 3 in figure 4) can be thought of as the sum of Reactions 1 and 2. Reaction 1 is the breakdown of ATP to ADP, which releases energy. Reaction 2, in which glucose is phosphorylated, requires energy. When Reactions 1 and 2 are coupled in the enzyme active site, Reaction 3 will occur spontaneously because: a. the energy required to form glucose-6-P in Reaction 2 is less than the energy released by ATP breakdown in Reaction 1.$ 49. Which of the following substances will be least likely to diffuse through a pure phosopholipid bilayer membrane that contains no proteins? a. sodium ion$ 50. If green algae cells in a buffer solution containing only inorganic salts are placed in a sealed container at room temperature with excess carbon dioxide gas and exposed to light, the cells will: a. live for many hours and grow.$ 51. The oxygen atoms in the H 2 O broken down during photosynthesis end up in: c. molecular O 2 released during photosynthesis.$ 52. Transcription is best represented by which of the pictures in figure 7? b. B$ 53. In the presence of oxygen, cells oxidize glucose completely to carbon dioxide and water according to the chemical equation shown in figure 5. In the process, about 35 molecules of ATP are generated per molecule of glucose oxidized, so that some of the energy released by oxidation is recovered as usable chemical energy. The principal role of O 2 in this process is to: a. accept electrons released by glucose oxidation, forming H 2 O. $ 54. Figure 6 shows a single replicated chromosome (consisting of two sister chromatids) just before mitosis. This chromosome contains: c. two double-stranded DNA molecules.$ 55. The replicated chromosome shown in figure 6 contains: c. DNA from only one of your parents.$ 56. Which of the following statements about DNA synthesis at the replication fork of a replicating DNA molecule is FALSE? c. The sequence of each newly synthesized single strand is identical to that of the parental single strand that served as its template.$ 57. The human hexokinase enzyme has the same function as the bacterial hexokinase enzyme but is different in its amino acid sequence. You have obtained a mutant bacterial strain in which the gene for hexokinase and its promoter are missing. If you introduce into your mutant strain a DNA plasmid engineered to contain the coding sequence of the human hexokinase gene, driven by the normal bacterial promoter, the resulting bacteria will now produce: b. the human form of hexokinase.$ 58. In a certain mutant strain of bacteria, the enzyme leucyl-tRNA synthetase mistakenly attaches isoleucine to leucyl-tRNA 10% of the time instead of attaching leucine. These bacteria will synthesize: b. proteins in which isoleucine is inserted at some positions normally occupied by leucine.$ 59. What is the relationship among genes, DNA, and chromosomes? a. Genes are composed of DNA and lie within chromosomes.$ 60. Our understanding of how genes function indicates that: e. genes code for proteins, which in turn produce individual traits.$