2010 Exam 2 key

2010 Exam 2 key - 1. A solution with a pH of 5.5 has how...

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Unformatted text preview: 1. A solution with a pH of 5.5 has how many more protons in it than a solution with a pH of 7.5? A) 5 times B 10 times 100 times D) 1,000 times 2. Interactions between proteins on the surface of the pollen grain and on the surface of the stigma are necessary for fertilization to proceed. What is the correct sequence of events that follow this interaction? figmwth of pollen tube, double fertilization, formation of sperm @ ormation of sperm, growth of pollen tube, double fertilization double fertilization, growth of pollen tube, formation of sperm D formation of sperm, double fertilization, growth of pollen tube growth of pollen tube, formation of sperm, double fertilization 3. Molecular phylogenies show all land plants are a monophyletic group. This suggests that A) there were many different transitions from aquatic to terrestrial habitats. B) wind-pollinated plants arose first. C) alternation of generations made it possible for the first land plants to colonize terrestrial habitats. there was a single transition from aquatic to terrestrial habitats. all of these. 4. The retaining of the zygote on the living gametophyte of land plants A] protects the zygote form herbivores. B helps in dispersal of the zygote. llows it to be nourished by the parent plant. D) is found only in seed plants. E) all of these. 5. Which of the following is true of Stomata? A) Stomata with guard cells occur in all land plants and define them as a monophyietic 1 cup. [3‘ Stomata open to allow gas exchange and close to decrease water loss. C) Stomata occur in all green plants and are the same as pores. D) Stomata open to increase both water absorption and gas exchange. E) all of these. 6. Which of the following is a correct element of alternation of generations? A The sporophyte is haploid and produces gametes. a? The sporophyte is diploid and produces spores. C) The gametophyte is haploid and produces spores. D) The gametophyte is diploid and produces gametes. E) Two spores unite to form a zygote. Bl0L13100 Exam 2, spring 2010 2 7. Which is the most diverse group of land plants? angiosperms B) pines C) gymnosperms D) ferns E) monocots 8. Which elements are responsible for the greater part of plant wet weight? A) carbon, phosphorus, oxygen B carbon, nitrogen, phosphorus @carbon, oxygen, hydrogen D) oxygen, hydrogen, phosphorus E) oxygen, hydrogen, nitrogen 9. What is the function of proton pumps localized in the plant plasma membrane? A) to store energy in the bonds of ATP B) to transfer phosphorous groups from ATP to proteins C) to transfer metal ions across the plasma membrane D to make the cytoplasm of plant cells more acidic 0 create a negative membrane potential 10. Where are ion channels localized? A) in the cytoplasm B inside of mitochondria @spanning plasma membranes ) on the extracellular surface of plasma membranes E) on the intracellular surface of plasma membranes 11. Both mycorrhizal fungi and rhizobia are able to supply plants with usable forms of nitrogen. From what sources do rhizobia and mycorrhizal fungi that are associated with plants obtain nitrogen? A) Fungi absorb N2 from the atmosphere, and rhizobia obtain nitrogen by decomposition of organic material. a) Fungi obtain nitrogen by decomposition of organic material, and rhizobia absorb N2 om the atmosphere. C) They both absorb ammonia from soil. D) They both absorb N2 from the atmosphere. E) They both obtain nitrogen by decomposition of organic material. 12. Iron shortage is the most common human nutritional deficiency in the world. Plants are the major source of iron in most diets, so researchers are interested in understanding their mechanism of iron intake and in developing iron-rich crops. Recently researchers showed (Vert et al., IRTl, an Arabidopsis transporter essential for iron uptake from the soil and for plant growth. Plant Cell 14 [2002] :1223-33) that under iron-deficient conditions, the lR'I'I gene is responsible for most of the iron uptake activity in roots. To demonstrate the importance of IRTI for iron accumulation, researchers measured leaf iron content in irt1-1 BlOLl3100 Exam 2, spring 2010 3 mutants containing deactivated IR'I‘1. Mutant plants were grown in iron-poor soil (irt1-1 in graph) and soil rich with iron (irt1-1 +Fe in graph). Wild-type (WT) plants grown in iron- poor soil were used as a control. Which of the graphs represent the data researchers might have received in their experiment? A200 @200 150 150 E E a E.» I: 100 a ‘00 E g 50 50 0 O lav-1 it'll-MFG! WT WT I'm-1 im-HFe B 20° D 200 150 150 E E. a - to If ‘00 '2 100 g s 50 so 0 0 WT MI-IOFO M14 “1., WT “laws 13. The addition of a phosphate group to a protein is called _, and it usually results in _ A dephosphorylation; mutation phosphorylation; protein activation or inactivation J signal transduction; changes in gene transcription D] photoreversibilty; changes in growth patterns E) kinase; changes in gene transcription 14. To find the gene that encodes for the blue-light receptor, researchers inserted the gene for the PHOTl protein into insect cells growing in culture. When they exposed the transgenic cells to blue light, they found that the PHOTI protein became phosphorylated. No other plant proteins were present in the insect cells. Which of the following is a reasonable conclusion from this result? A] The PHOTl protein enabled the insect cells to photosynthesize. B) The PHOT1 protein is not functional in insect cells. C) The PHOTl protein is not responsive to blue light. D The PHOTI protein is photoreversible. he PHOTl protein phosphorylated itself in the presence of blue light. BIOL13100 Exam 2. spring 2010 15. To understand how plant phototropic responses are regulated, a researcher performed following experiment. He exposed oat seedlings to light and then cut off tips of coleoptiles and placed them on agar blocks. Later the agar blocks were placed on decapitated coleoptiles of other individuals, and some seedlings were kept in dark while others were exposed to light. Based on your knowledge of auxin synthesis and mode of action, predict in what cases the decapitated coleoptiles would bend to the right. A) when the block was placed on the right side of the coleoptiles in dark only B) as long as light was coming from the right, decapitated coleoptiles bent to the right independently of agar block placement C) when the block was placed on the right side of the coleoptiles in both dark and light treatments D when the block was placed on the left side of the coleoptiles in dark only hen the block was placed on the left side of the coleoptiles in both dark and light treatments 16. Mammalian eyes sense light because they contain cells having molecules called opsins, which change structure when exposed to light. Which of the following plant molecule(s] would be analogous to mammalian opsins in their light-sensing ability? A) auxin kinases hytochromes D) cytokinins E) gibberellins 17. A population of plants experiences several years of severe drought. Much of the populatiou dies due to lack of water, but a few individuals survive. You set out to discover the physiological basis for their adaptation to such an extreme environmental change. You hypothesize that the survivors have the ability to synthesize higher levels of than their siblings do. A) Photl B) auxin C) gibberellin D cytokinin bscisic acid Use the following information when answering questions 18-. The shade avoidance response is a plant's way of changing its growth pattern when it is being shaded by another plant. Upon exposure to shade, many plants will grow taller, flatten their leaf angle, and extend their leaves further from their stems in order to reach full sunlight. Research performed by Pierik et a1. [Interactions between ethylene and gibberellins in phytochrome-mediated shade avoidance responses in tobacco. 2004. Plant Physiology 136:2928-36; http:/ /www.plantphysiol.org/cgi/ content/full / 136 /2 /2928) examined the role of ethylene and gibberellins on the shade avoidance response in tobacco plants. The shade avoidance response is known to involve phytochromes. BIOL13 100 Exam 2, spring 2010 5 18. When tobacco plants were exposed to far-red light, they exhibited increased stem length, petiole length, and petiole angle. These three responses are part of the shade avoidance response. When the same plants were exposed to small concentrations of ethylene while being exposed to far-red light, they exhibited even greater increases in stem length, petiole length, and petiole angle. in a subsequent experiment, tobacco plants showed an increase in ethylene production in response to far-red light. Moreover, mutant plants that are insensitive to ethylene did not show a shade avoidance response when exposed to far-red light Taken together, these data suggest that ethylene inhibits growth when tobacco plants are shaded by other plants. Q stimulates growth when tobacco plants are shaded by other plants. interferes with growth of the other plants. D) is not involved in the shade avoidance response. E) none of these. Ethylene stimulates growth regardless of sunlight or shade. 19. When the researchers inhibited the synthesis of gibberellins in the tobacco plants, neither ethylene nor far-red light could trigger a shade avoidance response. Taken together mm the data presented above, these data suggest that gibberellins r. re necessary to generate the shade avoidance response. = antagonize (act oppositely) the effects of ethylene on the shade avoidance response. C) are not involved in the shade avoidance response. D] are sufficient to stimulate growth when tobacco plants are shaded by other plants. 20. Angiosperms are unique in having double fertilization that forms endosperm. What is true about double fertilization in angiosperms? A) Two sperm combine with a polar nucleus to form endosperm. B) Two sperm combine with two eggs to form the zygote and endosperm. C) One sperm combines with the polar nuclei to form the zygote, and one sperm combines ‘th the egg to form endosperm. One sperm combines with the egg to form the zygote, and one sperm combines with the polar nuclei to form endosperm. 21. Pollen plays a critical role in the life cycle of all flowering plants. Pollen tubes perceive multiple extracellular signals during their extended growth (Johnson and Preuss (2002) Developmental Cell 2 [3): 273-281). Which of the following interactions could have come from cells of the female part of the flower as important sources of pollen guidance cues? A) discrimination among pollen grains, allowing only those that are appropriate to invade. B) entry of pollen tubes into female cell walls. C) establishing pollen polarity and adhesion-based pollen tube growth and motility. delivering sperm to the eggs in the interior of the flower. 6a” of these. 22. You begin exercising vigorously. This will. in a short time, cause your blood pH to begin dropping due to the release of carbon dioxide into your bloodstream. Which component of your body is responsible for deciding if your blood pH is far enough from normal that a response is necessary? A) lung 810L13100 Exam 2, spring 2010 6 rain ') muscle D) red blood cells E) skin 23. Trail Ridge Rd at Rocky Mountain National Park is the highest continuous motorway in the United States, with more than eight miles lying above 11,000 feet. The air pressure at 11,000 ft averages 506 mmHg, which is much lower than the air pressure in Miami Beach at about sea level. Given that the air pressure in Miami Beach is 760 mm Hg and oxygen makes up 21% of the air in Miami Beach, what percentage of oxygen and what partial pressure of oxygen would you be exposed to at 11,000 feet if you drive Trail Ridge Road? :_ 21%: 21 mm Hg 6"1%; 106 mm Hg C) 21%; 159 mm Hg D) 14%; 159 mm Hg E] 14%; 21 mm Hg 24. A mutation results in a form of hemoglobin that has binding sites for four molecules of oxygen but does not exhibit cooperative binding. Which of the following would result? A) Each hemoglobin molecule would bind only one molecule of oxygen. B] Oxygen would be delivered to the tissues more readily than in a normal individual. C] The oxygen-hemoglobin dissociation curve would be unaffected. D Both A and C would occur. one of the above would result. 25. Which of the following events would be predicted by the Bohr shift effect as the amount of carbon dioxide released from your tissues into the blood capillaries increases? A) The amount of oxygen in arterial blood would increase. B) The amount of oxygen in arterial blood would decrease. 4 he amount of oxygen in venous blood would increase. e amount of oxygen in venous blood would decrease. 26. A large decrease in albumin concentration in the plasma of a dog that has kidney disease would result in which of the following? _; 'ncrease in blood volume and decrease in extracellular fluid volume ecrease in blood volume and increase in extracellular fluid volume ‘ increase in blood volume and increase in extracellular fluid volume D) decrease in blood volume and decrease in extracellular fluid volume 27. What is the function of the sarcoplasmic reticulum? A) To store and release ATP To store and release ACh @0 store and release Ca2+ To store and release myosin E) To store and release troponin BlOLl3100 Exam 2, spring 2010 7 1.0 (—1 l W Thioether Pr Ci; isomer Gln linkage 0.5 62 500 550 600 650 700 750 800 28. Which absorbance spectrum is for Pfr? A 1 2 None of these; Pfr absorbs the 500 nm wavelengths of light. 29. Suppose lettuce seeds that have been stored in the dark are exposed to light at a wavelength 640 nm. What form will the phytochromes be in? A) Pr @Pfr C) None of these; instead, Photl will become dephosphorylated. 30. When an action potential from a motor neuron arrives at the neuromuscular junction (NMJ), a series of events occurs that leads to muscle contraction. Which of the following events will occur last (i.e., after all of the others)? A) ACh release action potential propagation down the T-tubules @onformanonal change in troponin depolarization of the muscle cell E) release of Ca2+ from the sarcoplasmic reticulum 31. What causes rigor mortis? i exhaustion of Ca2+ from the sarcoplasmic reticulum ack of ATP in dead tissue C) lack of acetylcholine (ACh) in dead tissue D) cessation of action potentials after death 810L13100 Exam 2. spring 2010 8 32. What would be the effect on muscle contraction if troponin were experimentally altered to no longer interact with tropomyosin, so the complex could no longer bind to actin? 6‘ Muscle contraction could no longer occur. uscles could not relax after contraction. Muscle contraction would be weakened but would still occur as long as tropomyosin is available. D) Muscles would become quite a bit stronger E) sarcomeres would become longer 33. Abnormally rapid breathing that often accompanies anxiety disorders may make you feel lightheaded. Feeling lightheaded is the feeling of being "spaced out" inside your head. It can also give you the sensation that if your lightheadedness worsens, you might lose consciousness. During abnormally rapid breathing, the amount of carbon dioxide in your blood __ and the pH of your blood _. A) increases; increases decreases; decreases decreases; increases D) increases; decreases E) increases; stays the same 34. When my cousin gets a panic attack and starts abnormally rapid breathing, my aunt makes him breathe in and out of a brown paper sandwich bag. Breathing in and out of a bag causes the carbon dioxide in the blood to ___. Breathing into a bag may appear a little strange, but it really helps my cousin during abnormally rapid breathing, probably because the pH of the blood _ when he re-inhales the air in the sandwich bag. He then "resets" his breathing rate by taking a brisk jog to counter hyperventilation. A) increase; increases B] decrease: decreases C decrease; increases increase; decreases ) increase; stays the same 35. Carbonic anhydrase is found in the red blood cells, not in the plasma of the blood. Why is this important? A) The protons produced by the carbonic anhydrase reaction induce the Bohr shift B) The partial pressure of C02 (measured in mmHg) drops when the carbonic anhydrase reaction produces bicarbonate ions. C) At tissues that are actively performing aerobic cell respiration, the carbonic anhydrase reaction makes hemoglobin more likely to release oxygen. D) Carbonic anhydrase activity makes the blood take up C02 from the tissues more efficiently. @ll of these 36. Researchers took a plant and removed the hypocotyl. Then they put an Agar plate containing radioactive auxin on the apical end of the hypocotyl. They put a blank receiving Bl0L13100 Exam 2, spring 2010 9 Agar plate on the basal end of the hypocotyl. When they did this, the donor plate was left with a lower concentration ofauxin and the receiving plate had a high concentration of auxin. Then they inverted the hypocotyl so that the receiving plate was apical and the radioactively marked auxin plate was basal. In doing so, they found that the receiving plate was still blank and that the radioactive plate still had a high concentration of auxin. What did they conclude from THIS experiment? A] The effect of unilateral blue light is mediated by auxin. B] This experiment demonstrates the effect ofauxin on hypocotyl growth. C The lateral transport of auxin plays a role in plant phototropism. @his experiment provides evidence for the polar transport of auxin. Auxin is an important plant hormone and with a known chemical identity. It is indoleacetic acid [IAAI-l]. Contraction 37. In this diagram, which is the G protein coupled receptor? A NE B] lpha-AR C GTP D] I’le E] [Pa 38. In the diagram above, where is the Sarcoplasmic reticulum [Sr]? A] 1 2 C 3 D] all ofthese E] none of these; there is no Sr in this diagram. 39. In this diagram, what molecule is a phospholipid? A] NE B] alpha-AR GTP PIP; E] 1P3 Biomaioo Exam 2, spring 2010 10 Name (PRINTED 1N CAPITAL LETTERS) PUlD 40. Suppose that you isolate a motor unit from a Vertebrate, that is, an intact motor neuron and its associated muscle fiber and you keep it functioning in a warm muscle bath with physiological saline solution. Ifyou were to replace all sodium chloride in the physiological saline solution with albumin, what would you predict the effect wouid be on the functioning motor unit? That is, could an action potential be initiated in the motor neuron ' - and would the muscle contract? Briefly explain your reasoning. I 10 pts 9 . . 41. A. Activation ofblue light receptor G. Membrane hyperpolarization [Vm becomes more negative] 13. Activation oin-A'I'Pase [-1. Opening of Ca1+ channels and increase in L intracellular Ca2+ C. Activation ofreceptor by ABA 1. Opening ofCl- channels and Cl- efflux D. [G efflux fl K. Secondary transport of Cl- into guard Cell I E. K+ influx L. Water efflux from the guard cell F. Membrane depolarization [Um becomes M. Water influx into the guard cell. _more positive) i. In the blank below, write the letters of the first and last events in the opening ofa stoma in a leaf. Choose the letters from the table above. You must get both right to get any points Firstevent ' - Lastevent - 1’2 pts ii. In the blank below. write FOUR letters of the events that occur between the first and last event that you identified above. You must get all four right to get any points, and you must not write more than four letters. Make sure your letters are legible. The order is not considered. intermediate events (four letters]: Ii ‘- 3' - f 3 pts iii. In the blank below, write the letters ofthe first and last events in the hormone-induced closing of a stoma in a leaf. Choose the letters from the table above. You must get both right to get any points. First event ' Last event ' f 2 pts iv. In the blank below, write FOUR letters of the events that occur between the first and last event that you identified in iii above. You must get all four right to get any points, and you must not write more than four letters. Make sure your letters are legible. The order is not considered. intermediate events [four letters]: I - . f3 pts BlOL'lBlOOExan12.spring2010 11 u ,‘a Name (PRINTED [N CAPlTAL LETTERS) ' - '-. PUID ESSAY QUESTION Place the following seven characteristics in sequence from the most ancient to the most recent appearance in the history of plant life. Write a brief essay with biological explanations and use evidence to justify claims about what must have happened previously to bring about the current state ofthings. Provide examples and use the terms ancestor, divergence, and lineage to write about the sequence for appearance of these traits in the family tree ofAngiosperin plants. - aerobic respiration - one cotyledon [monocot] - alternation of generations - pollen - endosperm to nourish a plant embryo - stomata - the fixation of atmospheric nitrogen via root-nodulatingI rhizobial bacteria i _: . :1" . , ' l a I! r i r "_ . l. t _ \ l l :1 _ " _ J ,_ t 54-. Mil ‘ ‘ :Ir ’ ,t -4 I40 pts Name (PRINTED IN CAPITAL LETTERS) PUH) EXPERIMENTAL DESIGN QUESTION Day length perceived by a leaf is a major environmental factor that controls the timing of flowering. Seasonal flowering is an important adaptive trait in plants for reproductive success. Plants monitor day length in the leaf to anticipate upcoming seasonal changes in order to time floral morphogenesis at the shoot apex for pollination at the best time of year for that plant. The action of mobile florigen, the 20 kDa protein FT [coded by the gene flowering locus T) is to promote flowering by changing the shoot apical meristem (SAM) from vegetative to reproductive growth. In Arabidopsis, transcription of PT is induced by long days in the tissues of cotyledons and leaves, and the resulting FT protein is then transported via the phloem to the shoot apical meristem (SAM). Although some genes that encode sensory or regulatory elements for photoperiodic flowering are conserved between the long-day (LD) plant Arabidopsis and the short-day (SD) plant rice, the gene networks that control rice flowering, and particularly flowering under LD conditions, are not well understood. In rice, there is a gene for RFT (the rice protein FT coded by the gene flowering locus T] but there are also other FT-like genes in rice. Questions remain about the functions for the various FT-like rice genes. Design a study to find out if the Arabidopsis FT protein is sufficient for floral induction under LD conditions in the SD plant rice. Assume that you are able to produce transgenic plants, you can culture and grow both wild-type and transgenic plants under SD [10 h of light/14 h of dark) or LD (14 h of light/ 10 h of dark] conditions, you have a kit for extracting total RNAs from various tissues or organs in order to quantify expression for your transgene, you are able to extract protein from any plant tissue, and you can collect and analyze protein samples from different parts of a plant frozen in liquid nitrogen and stored at —20°C until needed for analysis. Answer the questions on the next two pages about the design of your investigation. 3101.13100 Exam 2, spring 2010 13 Name (PRINTED 1N CAPITAL LETTERS) PUID a. State your research question. [5 pts .: ._. { r--1 c H n —_v - l ) ‘1’“ - z! ’1 1 J. 'v\. ' ' 5* H“1’1?~.Ln "'f "H'fi‘l l .._ I v I . _l. 1 ‘ ‘I w ‘ Er.) L -~.'.. -1'. :x._.« #; ‘3-"~‘-" "-' ‘_ In 1 ‘ w-‘--'.»'-. 1 Ce. b. Identify your experimental treatment variables !5 pts frllrl-‘Ir"{3'{')fl‘.j'.-‘ "if: 1! Jul PFC. Jill-’1, _ . "\ . “F . . . , t ,—v,;_ .—L"l b. Identify a response variable - what you would measure {5 pts .' '1 ~ - , -- " 'e 1—"\“ l-2_‘{r~\f_.i_1..l"r2" 5"- '= ‘5' LR! 3&1)... n I L -x_-.t. '.-_‘,-.‘\'-."~_ ".Au" x—- l C!(__J:"._:_\_. Cu ' -| *3 ‘2' ' _ . . - 'I‘ '- c. What is your positive control? I 3 pts .,. ."I' _'_- ...l ' . _ -' -' ' “-'-"--1 UK: “Li ’.:_:-_-J "-1- '— t 0* 3.11".“zs‘p: 3101.13100 Exam 2. spring 2010 14. Graph the results you expect to get ifSD rice plants do respond to FT protein under LD conditions. If: pts l " I-flfllflmmMMIlllIlllllIl a I IIEIIIIIIIIII .. I_.I -EEMEMEIIII fl“ ELI-I55! HER-III In" III-III III-III rm": "‘ " 'EEI- IIIIIII 'IIIII III-III ---== III-III..- III-IIIIIIIII III-lllflflfllll Ill-IIIIIIIII ._ol IIIIII-III “1:1IIIHIIUIIIII » 'HIHIIEEIIIIII :llll III-II IEIIHIII III E IIEEHI III lflflfi In flIl_ , :; mun-Ill III km? l 3.. III!!!- "' ' ' ' I EI-I' III I AJ ll g. Label the X and y axes to show what they represent (8 pts h. Explain what the bars or data points represent. 5 pts ":7: I. i ‘-. .:'- I I- '- ‘.. I. “r fix I": z: _I- LUV. 3:. if". f -' .1 ' :li'. { I - '.; if, ..'1.. 1:7. CCLUUSL“: £‘Du—J0ri‘mj 047-5b rr-Cc- LLnoLLl’ Ll) coach-Hon f. Describe the results you predict if rice plants do NOT respond like the Arabidopsis to the leaf-generated mobile FT protein florigen. Explain your reasoning. IS pts . ‘ . . -. - \ I A -; I'. . ‘- \l.t-_-~I-I-.._ '.,. r.. . . .‘._. :. . .. ' '- .. ..-.. -. ._.;._ _o_.|'_.1_‘|.: .fi' ‘1' - . .x. ';i'._':"_." l. '.I g: '." 8101.131le Exam 2,5pring 2010 15 ...
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2010 Exam 2 key - 1. A solution with a pH of 5.5 has how...

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