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Q.
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Rationale
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| 1. B | Definition |
| 2. B | Definition |
| 3. C | Definition |
| 4. E | Example discussed in class. |
| 5. A | Definition |
| 6. C | 3 phosphates (count them); sugar is ribose (no missing OH group), so ATP. |
| 7. A | Definition |
| 8. E | This is easiest to see in the lower part of the figure; there's only one protein attached, right at the point where new DNA is growing (arrow head), so this can only be DNA polymerase. Same logic works on upper strand (enzyme is found at growing arrow head), but its more confused because of all the other enzymes needed for lagging strand synthesis. |
| 9. C | The "leading strand" is defined as the newly replicating strand that is being synthesized in the same direction as DNA is unwinding. |
| 10. E | Each codon consists of 3 nucleotides, so multiply number of amino acids by 3. Elementary, my dear Watson. |
| 11. A | Transcription is defined as synthesis of RNA from a DNA template, and that's obviously what's happening here, since the product contains U instead of T. |
| 12. A | "Hello darkness my old xfsfdsruiesrrpoierioeiroiep" = exon-intron. If you weren't in class Wednesday, you missed the audio demo. |
| 13. B | Translation = making polypeptides, using mRNA, ribosomes, t-RNAs, etc. RNA polymerase is involved in making RNA (transcription), a different process. |
| 14. C | Example from class, text, and notes. |
| 15. C | First,
write down the complementary RNA: UCAUGUAUGAU..... Second, locate the first AUG "start" codon from the left: (UC) AUG UAU GAU..... Third, consult the genetic code table for the correct amino acids: met-tyr |
| 16. D | Animal cilia (and flagella) are distinguished by the "9+2" pattern of microtubules. Centrioles have a ring of 9 bundles (in "3's" instead of "2's"), but do not have 2 central microtubules. Other choices are not relevant. |
| 17. B | Microtubules are the largest of cytoskeletal fibers, and the only ones associated with the "9+2" pattern |
| 18. E | Both dynein and kinesin are common motor proteins. |
| 19. E | All these statements are true. |
| 20. A | Oxidation = loss of electrons (also can be loss of H). Choices b-d involve gain, not loss, so these are reductions, not oxidations. LEO the lion says GER! |
| 21. A | "Chemiosmosis" refers to the building up and discharging of proton gradients across a membrane. Only choice (a) applies. |
| 22. E | Several of the answer choices are true statements, but irrelevant to the question asked. E is the clear answer. |
| 23. A | Glycolysis occurs in the cytoplasm, outside the mitochondrion. |
| 24. B | H+ ions accumulate in the compartment between inner and outer mitochondrial membrane, labeled "Compartment B" here. |
| 25. C | This refers to the Krebs cycle, which occurs inside the mitochondrial matrix, labeled "Compartment C" here. |
| 26. D | Oxygen is the common terminal electron acceptor; common electron acceptors include NAD + and others not listed here. |
| 27. D | This is the Krebs cycle (aka TCA cycle, citric acid cycle) shown in class, probably the easiest question on this test! |
| 28. C | A major function of the Krebs cycle is to oxidize pyruvate all the way to CO 2 and H 2O, stripping off H atoms and passing them on to the electron transport system with NAD + as the electron carrier. So X must represent NAD + and Y must represent NADH. |
| 29. D | UConn's favorite fermentation, I think. Note that pyruvate is not a waste product -- it must be used as the electron acceptor in fermentation, and once it has accepted electrons it is no longer pyruvate but ethanol or lactic acid or some other waste product. |
| 30. A | The description is very similar to the example we discussed in class, with transferrin as the iron carrier. Cholesterol is indeed carried by LDLs as opposed to floating free in the blood, and a good thing this is! |
| 31. E | Ion gradients can only be generated by some active transport process, typically by ATP pumps. Symport or antiport are conceivable alternatives, but not in the answer choices here -- choice (c) cannot be correct since no antiporter would exchange gigantic proteins (enzymes) for ions. (This question is right off the Biology Place) |
| 32. B | Another question right off the Biology Place. This is very obviously plasmolysis, assuming you remember the definition! |
| 33. D | Both AT and FD use proteins to carry substances across membranes, but FD doesn't use energy while AT does. |
| 34. E | First fact learned about membrane structure. |
| 35. B | Of choices listed, only glucose is polar/charged. Oxygen is very nonpolar (hence its poor solubility in water); fatty acids are clearly nonpolar and dissolve happily in the lipid bilayer; and ethanol is equally happy in both polar and nonpolar environments and needs no carrier, a fact that explains why our brains start reeling quickly after consuming enough drinks to raise our blood concentration of alcohol enough to feel the effect. |
| 36. C | Pure water is the best cure for wilted plants because it is hypotonic (under the osmotic strength of the cell) |
| 37. D | Definition |
| 38. C | From practice test |
| 39. D | Definition |
| 40. C | They're called G-proteins because they use GTP; when this splits to GDP,they become inactive and must await a signal event to trigger another round of GTP activation . |
| 41. D | Until cells start synthesizing DNA, they are not going to divide. The transition from G 1 (or G o) to S is the critical division commitment. |
| 42. D | Of the many distinguishing features, only D is relevant here. (a) occurs in mitosis but not meiosis; (b) and (c) occurs in both processes, except preceding meiosis II, the inverse of the question asked. |
| 43. C | The question tells you that 2N=6, so N=3. One look at the figure should convince you there are only 3 chromosomes here (each with a pair of sister chromatids), and they don't look alike so the homologous pairs have already been separated. This is clearly metaphase because everything is lined up on one plane. Conclusion: metaphase of meiosis II. |
| 44. D | Example was discussed in class. Colchicine is a common metaphase arrest drug. |
| 45. B | Gametes always have 1/2 the chromosomes of somatic cells. |