This Document Contains Chapters 8 to 9 Chapter 8: Photosynthesis 8.1 Multiple-Choice Questions 1) In autotrophic bacteria, where is chlorophyll located? A) in chloroplast membranes B) in chloroplast stroma C) in the ribosomes D) in the nucleoid E) in the in folded plasma membrane Answer: E 2) If photosynthesizing green algae are provided with CO2 containing heavy oxygen (18O), later analysis will show that all of the following molecules produced by the algae contain 18O except A) 3-phosphoglycerate. B) glyceraldehyde 3-phosphate (G3P). C) glucose. D) ribulose bisphosphate (RuBP). E) O2. Answer: E 3) Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? A) CO2 and glucose B) H2O and O2 C) ADP, ℗i, and NADP+ D) electrons and H+ E) ATP and NADPH Answer: E 4) Where does the Calvin cycle take place? A) stroma of the chloroplast B) thylakoid membrane C) cytoplasm surrounding the chloroplast D) interior of the thylakoid (thylakoid space) E) outer membrane of the chloroplast Answer: A 5) In any ecosystem, terrestrial or aquatic, which of the following are always necessary? A) autotrophs and heterotrophs B) producers and primary consumers C) photosynthesizers D) autotrophs E) green plants Answer: D 6) When oxygen is released as a result of photosynthesis, it is a direct by-product of A) reducing NADP+. B) splitting water molecules. C) chemiosmosis. D) the electron transfer system of photosystem I. E) the electron transfer system of photosystem II. Answer: B 7) A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment? A) red and yellow B) blue and violet C) green and yellow D) blue, green, and red E) green, blue, and yellow Answer: B 8) In the thylakoid membranes, what is the main role of the pigment molecules in a light-harvesting complex? A) split water and release oxygen to the reaction-center chlorophyll B) transfer light energy to the reaction-center chlorophyll C) synthesize ATP from ADP and ℗i D) transfer electrons to ferredoxin and then NADPH E) concentrate photons within the stroma Answer: B 9) Which of the following events occurs in the light reactions of photosynthesis? A) NADP is produced. B) NADPH is reduced to NADP+. C) Carbon dioxide is incorporated into PGA. D) ATP is phosphorylated to yield ADP. E) Light is absorbed and funneled to reaction-center chlorophyll a. Answer: E 10) Which statement describes the functioning of photosystem II? A) Light energy excites electrons in the thylakoid membrane electron transport chain. B) Photons are passed along to a reaction-center chlorophyll. C) The P680 chlorophyll donates a pair of protons to NADP+, which is thus converted to NADPH. D) The electron vacancies in P680+ are filled by electrons derived from water. E) The splitting of water yields molecular carbon dioxide as a by-product. Answer: D 11) Which of the following are directly associated with photosystem I? A) harvesting of light energy by ATP B) receiving electrons from the thylakoid membrane electron transport chain C) generation of molecular oxygen D) extraction of hydrogen electrons from the splitting of water E) passing electrons to the thylakoid membrane electron transport chain Answer: B 12) Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be A) to determine if they have thylakoids in the chloroplasts. B) to test for liberation of O2 in the light. C) to test for CO2 fixation in the dark. D) to do experiments to generate an action spectrum. E) to test for production of either sucrose or starch. Answer: B 13) What are the products of linear electron flow? A) heat and fluorescence B) ATP and P700 C) ATP and NADPH D) ADP and NADP+ E) P700 and P680 Answer: C 14) As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from? A) photosystem II B) photosystem I C) cyclic electron flow D) linear electron flow E) chlorophyll Answer: C 15) What does the chemiosmotic process in chloroplasts involve? A) establishment of a proton gradient across the thylakoid membrane B) diffusion of electrons through the thylakoid membrane C) reduction of water to produce ATP energy D) movement of water by osmosis into the thylakoid space from the stroma E) formation of glucose, using carbon dioxide, NADPH, and ATP Answer: A 16) Suppose the interior of the thylakoids of isolated chloroplasts were made acidic and then transferred in the dark to a pH 8 solution. What would be likely to happen? A) The isolated chloroplasts will make ATP. B) The Calvin cycle will be activated. C) Cyclic photophosphorylation will occur. D) The isolated chloroplasts will generate oxygen gas. E) The isolated chloroplasts will reduce NADP+ to NADPH. Answer: A 17) In a plant cell, where are the ATP synthase complexes located? A) thylakoid membrane only B) plasma membrane only C) inner mitochondrial membrane only D) thylakoid membrane and inner mitochondrial membrane E) thylakoid membrane and plasma membrane Answer: D 18) In mitochondria, chemiosmosis translocate protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocate protons from A) the stroma to the photosystem II. B) the matrix to the stroma. C) the stroma to the thylakoid space. D) the intermembrane space to the matrix. E) the thylakoid space to the stroma. Answer: C 19) Which of the following statements best describes the relationship between photosynthesis and respiration? A) Respiration runs the biochemical pathways of photosynthesis in reverse. B) Photosynthesis stores energy in complex organic molecules, whereas respiration releases it. C) Photosynthesis occurs only in plants and respiration occurs only in animals. D) ATP molecules are produced in photosynthesis and used up in respiration. E) Respiration is anabolic and photosynthesis is catabolic. Answer: B 20) Where are the molecules of the electron transport chain found in plant cells? A) thylakoid membranes of chloroplasts B) stroma of chloroplasts C) outer membrane of mitochondria D) matrix of mitochondria E) cytoplasm Answer: A 21) In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during A) photosynthesis only. B) respiration only. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration only. Answer: C 22) Reduction of oxygen to form water occurs during A) photosynthesis only. B) respiration only. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) the dark reactions only. Answer: B 23) The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during A) photosynthesis. B) respiration. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration. Answer: D 24) Generation of proton gradients across membranes occurs during A) photosynthesis. B) respiration. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration. Answer: C 25) What is the relationship between wavelength of light and the quantity of energy per photon? A) They have a direct, linear relationship. B) They are inversely related. C) They are logarithmically related. D) They are separate phenomena. E) They are only related in certain parts of the spectrum. Answer: B 26) P680+ is said to be the strongest biological oxidizing agent. Given its function, why is this necessary? A) It is the receptor for the most excited electron in either photosystem. B) It is the molecule that transfers electrons to plastoquinone (Pq) of the electron transfer system. C) It transfers its electrons to reduce NADP+ to NADPH. D) It obtains electrons from the oxygen atom in a water molecule, so it must have a stronger attraction for electrons than oxygen has. E) It has a positive charge. Answer: D 27) Some photosynthetic bacteria (e.g., purple sulfur bacteria) have only photosystem I, whereas others (e.g., cyanobacteria) have both photosystem I and photosystem II. Which of the following might this observation imply? A) Photosystem II was selected against in some species. B) Photosynthesis with only photosystem I is more ancestral. C) Photosystem II may have evolved to be more photoprotective. D) Linear electron flow is more primitive than cyclic flow of electrons. E) Cyclic flow is more necessary than linear electron flow. Answer: B 28) Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants? A) They serve as accessory pigments to increase light absorption. B) They protect against oxidative damage from excessive light energy. C) They shield the sensitive chromosomes of the plant from harmful ultraviolet radiation. D) They reflect orange light and enhance red light absorption by chlorophyll. E) They take up and remove toxins from the groundwater. Answer: B 29) In thylakoids, protons travel through ATP synthase from the thylakoid space to the stroma. Therefore, the catalytic "knobs" of ATP synthase would be located A) on the side facing the thylakoid space. B) on the ATP molecules themselves. C) on the pigment molecules of photosystem I and photosystem II. D) on the stromal side of the membrane. E) built into the center of the thylakoid stack (granum). Answer: D 30) In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered in components of the electron transport chain. What do they do? A) donate electrons B) act as reducing agents C) act as oxidizing agents D) transport protons within the mitochondria and chloroplasts E) both oxidize and reduce during electron transport Answer: E 31) In a cyanobacterium, the reactions that produce NADPH occur in A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but are not part of photosynthesis. Answer: A 32) The reactions that produce molecular oxygen (O2) take place in A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but are not part of photosynthesis. Answer: A 33) A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask. A) The dissolved oxygen in the flask with algae will always be higher. B) The dissolved oxygen in the flask with algae will always be lower. C) The dissolved oxygen in the flask with algae will be higher in the light, but the same in the dark. D) The dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark. E) The dissolved oxygen in the flask with algae will not be different from the control flask at any time. Answer: D 34) The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find? A) The pH within the thylakoid is less than that of the stroma. B) The pH of the stroma is lower than that of the other two measurements. C) The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol. D) The pH of the thylakoid space is higher than that anywhere else in the cell. E) There is no consistent relationship. Answer: A 35) Reduction of NADP+ occurs during A) photosynthesis. B) respiration. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. Answer: A 36) What compound provides the reducing power for the Calvin cycle reactions? A) ATP B) NAD+ C) NADH D) NADP+ E) NADPH Answer: E 37) What would be the expected effect on plants if the atmospheric CO2 concentration was doubled? A) All plants will experience increased rates of photosynthesis. B) C3 plants will have faster growth; C4 plants will be minimally affected. C) C4 plants will have faster growth; C3 plants will be minimally affected. D) C3 plants will have faster growth; C4 plants will have slower growth. E) Plant growth will not be affected because atmospheric CO2 concentrations are never limiting for plant growth. Answer: B 38) Where do the enzymatic reactions of the Calvin cycle take place? A) stroma of the chloroplast B) thylakoid membranes C) matrix of the mitochondria D) cytosol around the chloroplast E) thylakoid space Answer: A 39) What is the primary function of the Calvin cycle? A) use ATP to release carbon dioxide B) use NADPH to release carbon dioxide C) split water and release oxygen D) transport RuBP out of the chloroplast E) synthesize simple sugars from carbon dioxide Answer: E 40) In C3 photosynthesis, the reactions that require ATP take place in A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but are not part of photosynthesis. Answer: B 41) The NADPH required for the Calvin cycle comes from A) reactions initiated in photosystem I. B) reactions initiated in photosystem II. C) the citric acid cycle. D) glycolysis. E) oxidative phosphorylation. Answer: A 42) Reactions that require CO2 take place in A) the light reactions alone. B) the Calvin cycle alone. C) both the light reactions and the Calvin cycle. D) neither the light reactions nor the Calvin cycle. E) the chloroplast, but are not part of photosynthesis. Answer: B 43) Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? A) The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, ℗i, and NADP+ to the light reactions. B) The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. C) The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. D) The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. E) There is no relationship between the light reactions and the Calvin cycle. Answer: A 44) In the process of carbon fixation, RuBP attaches a CO2 to produce a six-carbon molecule, which is then split to produce two molecules of 3-phosphoglycerate. After phosphorylation and reduction produces glyceraldehyde 3-phosphate (G3P), what more needs to happen to complete the Calvin cycle? A) addition of a pair of electrons from NADPH B) inactivation of RuBP carboxylase enzyme C) regeneration of ATP from ADP D) regeneration of RuBP E) regeneration of NADP+ Answer: D 45) The phylogenetic distribution of the enzyme rubisco is limited to A) C3 plants only. B) C3 and C4 plants. C) all photosynthetic eukaryotes. D) all known photoautotrophs, both bacterial and eukaryotic. E) all living cells. Answer: D 46) Photorespiration occurs when rubisco reacts RuBP with A) CO2. B) O2. C) glyceraldehyde 3-phosphate. D) 3-phosphoglycerate. E) NADPH. Answer: B 47) Why are C4 plants able to photosynthesize with no apparent photorespiration? A) They do not participate in the Calvin cycle. B) They use PEP carboxylase to initially fix CO2. C) They are adapted to cold, wet climates. D) They conserve water more efficiently. E) They exclude oxygen from their tissues. Answer: B 48) CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they A) fix CO2 into organic acids during the night. B) fix CO2 into sugars in the bundle-sheath cells. C) fix CO2 into pyruvate in the mesophyll cells. D) use the enzyme phosphofructokinase, which outcompetes rubisco for CO2. E) use photosystem I and photosystem II at night. Answer: A 49) Photorespiration lowers the efficiency of photosynthesis by A) consuming carbon dioxide. B) reducing the amount of 3-phosphoglycerate formed. C) generating excess ATP. D) producing ribulose bisphosphate. E) denaturing rubisco. Answer: B 50) The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why? A) Each one minimizes both water loss and rate of photosynthesis. B) C4 compromises on water loss and CAM compromises on photorespiration. C) Both minimize photorespiration but expend more ATP during carbon fixation. D) CAM plants allow more water loss, whereas C4 plants allow less CO2 into the plant. E) C4 plants allow less water loss but CAM plants allow more water loss. Answer: C 51) Compared to C3 plants, C4 plants A) can continue to fix CO2 even at relatively low CO2 concentrations and high oxygen concentrations. B) have higher rates of photorespiration. C) do not use rubisco for carbon fixation. D) grow better under cool, moist conditions. E) make a four-carbon compound, oxaloacetate, which is then delivered to the citric acid cycle in mitochondria. Answer: A 8.2 Art Questions Figure 8.1 1) Figure 8.1 shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different? A) Green and yellow wavelengths inhibit the absorption of red and blue wavelengths. B) Bright sunlight destroys photosynthetic pigments. C) Oxygen given off during photosynthesis interferes with the absorption of light. D) Other pigments absorb light in addition to chlorophyll a. E) Aerobic bacteria take up oxygen, which changes the measurement of the rate of photosynthesis. Answer: D 2) What wavelength of light in Figure 8.1 is most effective in driving photosynthesis? A) 420 mm B) 475 mm C) 575 mm D) 625 mm E) 730 mm Answer: A Use Figure 8.2 and the compounds labeled A, B, C, D, and E to answer the following questions. Figure 8.2 3) If ATP used by this plant is labeled with radioactive phosphorus, which molecule or molecules of the Calvin cycle will be radioactively labeled first? A) B only B) B and C only C) B, C, and D only D) B and E only E) B, C, D, and E Answer: D 4) Which molecule(s) of the Calvin cycle is (are) also found in glycolysis? A) B, C, E, and 3-phosphoglycerate B) B, C, and E only C) 3-phosphoglycerate only D) B, C, D, and 3-phosphoglycerate only E) E only Answer: D 5) If the carbon atom of each of the incoming CO2 molecules is labeled with a radioactive isotope of carbon, which organic molecules will be radioactively labeled after one cycle? A) C only B) B, C, D, and E C) C, D, and E only D) B and C only E) B and D only Answer: B 6) To identify the molecule that accepts CO2, Calvin and Benson manipulated the carbon-fixation cycle by either cutting off CO2 or cutting off light from cultures of photosynthetic algae. They then measured the concentrations of various metabolites immediately following the manipulation. How would these experiments help identify the CO2 acceptor? Study Figure 8.2 to help you in determining the correct answer. A) The CO2 acceptor concentration would decrease when either the CO2 or light is cut off. B) The CO2 acceptor concentration would increase when either the CO2 or light is cut off. C) The CO2 acceptor concentration would increase when the CO2 is cut off, but decrease when the light is cut off. D) The CO2 acceptor concentration would decrease when the CO2 is cut off, but increase when the light is cut off. E) The CO2 acceptor concentration would stay the same regardless of the CO2 or light. Answer: C Figure 8.3 7) Which of the following statements is true concerning Figure 8.3? A) It represents cell processes involved in C4 photosynthesis. B) It represents the type of cell structures found in CAM plants. C) It represents an adaptation that maximizes photorespiration. D) It represents a C3 photosynthetic system. E) It represents a relationship between plant cells that photosynthesize and those that cannot. Answer: A 8.3 Scenario Questions Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light. 1) What did Engelmann conclude about the congregation of bacteria in the red and blue areas? A) Bacteria released excess carbon dioxide in these areas. B) Bacteria congregated in these areas due to an increase in the temperature of the red and blue light. C) Bacteria congregated in these areas because these areas had the most oxygen being released. D) Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths. E) Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis. Answer: C 2) An outcome of this experiment was to help determine the relationship between A) heterotrophic and autotrophic organisms. B) wavelengths of light and the rate of aerobic respiration. C) wavelengths of light and the amount of heat released. D) wavelengths of light and the rate of photosynthesis. E) the concentration of carbon dioxide and the rate of photosynthesis. Answer: D 3) If you ran the same experiment without passing light through a prism, what would you predict? A) There would be no difference in results. B) The bacteria would be relatively evenly distributed along the algal filaments. C) The number of bacteria present would decrease due to an increase in the carbon dioxide concentration. D) The number of bacteria present would increase due to an increase in the carbon dioxide concentration. E) The number of bacteria would decrease due to a decrease in the temperature of the water. Answer: B A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Because the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. 4) What wavelengths of light should be used to maximize plant growth with a minimum of energy expenditure? A) full-spectrum white light B) green light C) a mixture of blue and red light D) yellow light E) UV light Answer: C 5) A gardener is concerned that her greenhouse is getting too hot from too much light, and seeks to shade her plants with colored translucent plastic sheets, the color of which allows passage of only that wavelength. What color should she used to reduce overall light energy, but still maximize plant growth? A) green B) blue C) yellow D) orange E) Any color will work equally well. Answer: B 6) Halobacterium has a photosynthetic membrane that appears purple. Its photosynthetic action spectrum is the inverse of the action spectrum for green plants. (That is, the Halobacterium action spectrum has a peak where the green plant action spectrum has a trough.) What wavelengths of light do the Halobacterium photosynthetic pigments absorb? A) red and yellow B) blue, green, and red C) green and yellow D) red and green E) blue and red Answer: C 8.4 End-of-Chapter Questions 1) The light reactions of photosynthesis supply the Calvin cycle with A) light energy. B) CO2 and ATP. C) H2O and NADPH. D) ATP and NADPH. E) sugar and O2. Answer: D 2) Which of the following sequences correctly represents the flow of electrons during photosynthesis? A) NADPH → O2 → CO2 B) H2O → NADPH → Calvin cycle C) NADPH → chlorophyll → Calvin cycle D) H2O → photosystem I → photosystem II E) NADPH → electron transport chain → O2 Answer: B 3) How is photosynthesis similar in C4 plants and CAM plants? A) In both cases, electron transport is not used. B) Both types of plants make sugar without the Calvin cycle. C) In both cases, rubisco is not used to fix carbon initially. D) Both types of plants make most of their sugar in the dark. E) In both cases, thylakoids are not involved in photosynthesis. Answer: C 4) Which of the following statements is a correct distinction between autotrophs and heterotrophs? A) Only heterotrophs require chemical compounds from the environment. B) Cellular respiration is unique to heterotrophs. C) Only heterotrophs have mitochondria. D) Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. E) Only heterotrophs require oxygen. Answer: D 5) Which of the following does not occur during the Calvin cycle? A) carbon fixation B) oxidation of NADPH C) release of oxygen D) regeneration of the CO2 acceptor E) consumption of ATP Answer: C 6) In mechanism, photophosphorylation is most similar to A) substrate-level phosphorylation in glycolysis. B) oxidative phosphorylation in cellular respiration. C) the Calvin cycle. D) carbon fixation. E) reduction of NADP+. Answer: B 7) Which process is most directly driven by light energy? A) creation of a pH gradient by pumping protons across the thylakoid membrane B) carbon fixation in the stroma C) reduction of NADP+ molecules D) removal of electrons from chlorophyll molecules E) ATP synthesis Answer: D Chapter 9: The Cell Cycle 9.1 Multiple-Choice Questions 1) Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells? A) 4 B) 8 C) 16 D) 32 E) 64 Answer: D 2) If there are 20 chromatids in a cell, how many centromeres are there? A) 10 B) 20 C) 30 D) 40 E) 80 Answer: B 3) In eukaryotic cells, chromosomes are composed of DNA A) and RNA. B) only. C) and proteins. D) and phospholipids. Answer: C 4) What is produced if a cell divides by mitosis but does not undergo cytokinesis? A) two cells, one cell containing two nuclei and a second cell without a nucleus B) two cells, each cell with half of the genetic material of the parent cell C) one cell with one nucleus containing half of the genetic material of the parent cell D) one cell with two nuclei, each identical to the nucleus of the parent cell Answer: D 5) Humans produce skin cells by mitosis and gametes by meiosis. The nuclei of skin cells produced by mitosis will have A) half as much DNA as the nuclei of gametes produced by meiosis. B) the same amount of DNA as the nuclei of gametes produced by meiosis. C) twice as much DNA as the nuclei of gametes produced by meiosis. D) four times as much DNA as the nuclei of gametes produced by meiosis. Answer: C 6) Compared to most prokaryotic cells, eukaryotic cells typically have A) more DNA molecules and larger genomes. B) the same number of DNA molecules but larger genomes. C) the same number of DNA molecules and similarly sized genomes. D) fewer DNA molecules but larger genomes. E) fewer DNA molecules and smaller genomes. Answer: A 7) At which phase are centrioles beginning to move apart in animal cells? A) telophase B) anaphase C) prometaphase D) metaphase E) prophase Answer: E 8) If there are 20 centromeres in a cell at anaphase, how many chromosomes are there in each daughter cell following cytokinesis? A) 10 B) 20 C) 30 D) 40 E) 80 Answer: A 9) Where do the microtubules of the spindle originate during mitosis in animal cells? A) centromere B) centrosome C) centriole D) chromatid E) kinetochore Answer: B 10) Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must affect A) the formation of the mitotic spindle. B) anaphase. C) formation of the centrioles. D) chromatid assembly. E) the S phase of the cell cycle. Answer: A 11) Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? A) kinetochores B) Golgi-derived vesicles C) actin and myosin D) centrioles and centromeres E) tubulin and dynein Answer: B 12) Movement of the chromosomes during anaphase would be most affected by a drug that prevents A) nuclear envelope breakdown. B) cell wall formation. C) elongation of microtubules. D) shortening of microtubules. E) formation of a cleavage furrow. Answer: D 13) Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA? A) G0 B) G1 C) S D) G2 E) M Answer: D 14) A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. How many picograms would be found at the end of S and the end of G2? A) 8; 8 B) 8; 16 C) 16; 8 D) 16; 16 E) 12; 16 Answer: D 15) The beginning of anaphase is indicated by which of the following? A) Chromatids lose their kinetochores. B) Cohesin attaches the sister chromatids to each other. C) Cohesin is cleaved enzymatically. D) Kinetochores attach to the metaphase plate. E) Spindle microtubules begin to polymerize. Answer: C 16) During which phase of mitosis do the chromatids become chromosomes? A) telophase B) anaphase C) prophase D) metaphase E) cytokinesis Answer: B 17) What is a cleavage furrow? A) a ring of vesicles forming a cell plate B) the separation of divided prokaryotes C) a groove in the plasma membrane between daughter nuclei D) the metaphase plate where chromosomes attach to the spindle E) the space that is created between two chromatids during anaphase Answer: C 18) Using which of the following techniques would enable your lab group to distinguish between a cell in G2 and a cell from the same organism in G1? A) fluorescence microscopy B) electron microscopy C) spectrophotometry D) radioactive-labeled nucleotides E) labeled kinetochore proteins Answer: D 19) You have the technology necessary to measure each of the following in a sample of animal cells: chlorophylls, organelle density, picograms of DNA, cell wall components, and enzymatic activity. Which would you expect to increase significantly from M to G1? A) organelle density and enzymatic activity B) cell wall components and DNA C) chlorophyll and cell walls D) organelle density and cell walls E) chlorophyll and DNA Answer: A 20) A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the spindle. Which of the following would result if colchicine is added to a sample of cells in G2? A) The cells would immediately die. B) The cells would be unable to begin M and stay in G2. C) The chromosomes would coil and shorten but have no spindle to which to attach. D) The chromosomes would segregate but in a disorderly pattern. E) Each resultant daughter cell would also be unable to form a spindle. Answer: C 21) Motor proteins require which of the following to function in the movement of chromosomes toward the poles of the mitotic spindle? A) intact centromeres B) a microtubule-organizing center C) a kinetochore attached to the metaphase plate D) ATP as an energy source E) synthesis of cohesin Answer: D 22) When a cell is in late anaphase of mitosis, which of the following will we see? A) a clear area in the center of the cell B) chromosomes clustered at the poles C) individual chromatids beginning to separate from one another D) chromosomes clustered tightly at the center E) breaking down of the nuclear envelope Answer: A 23) Cells from advanced malignant tumors often have very abnormal chromosomes as well as an abnormal number of chromosomes. What might explain the association between malignant tumors and chromosomal abnormalities? A) Cancer cells are no longer density dependent. B) Cancer cells are no longer anchorage dependent. C) Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities. D) Chromosomally abnormal cells still have normal metabolism. E) Transformation introduces new chromosomes into cells. Answer: C 24) Which is the first checkpoint in the cell cycle where a cell will be caused to exit the cycle if this point is not passed? A) G0 B) G1 C) G2 D) S E) previous M Answer: B 25) Which of the following is released by platelets in the vicinity of an injury? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk Answer: A 26) Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk Answer: D 27) Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk Answer: E 28) Which of the following triggers the cell's passage past the G2 checkpoint into mitosis? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk Answer: B 29) The cyclin component of MPF is destroyed toward the end of which phase? A) G0 B) G1 C) S D) G2 E) M Answer: E 30) Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called A) ATPases. B) kinetochores. C) kinases. D) estrogen receptors. E) cyclins. Answer: E 31) The MPF protein complex turns itself off by A) activating a process that destroys cyclin components. B) activating an enzyme that stimulates cyclin. C) binding to chromatin. D) exiting the cell. E) activating the anaphase-promoting complex. Answer: A 32) Density-dependent inhibition is explained by which of the following? A) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors. B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing. C) As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. D) As cells become more numerous, more and more of them enter the S phase of the cell cycle. E) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism. Answer: B 33) Which of the following is true concerning cancer cells? A) They do not exhibit density-dependent inhibition when growing in culture. B) When they stop dividing, they do so at random points in the cell cycle. C) They are not subject to cell cycle controls. D) When they stop dividing, they do so at random points in the cell cycle, and they are not subject to cell cycle controls. E) When they stop dividing, they do so at random points in the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density-dependent inhibition when growing in culture. Answer: E 34) Which of the following describes cyclin-dependent kinase (Cdk)? A) Cdk is inactive, or "turned off," in the presence of cyclin. B) Cdk is present throughout the cell cycle. C) Cdk is an enzyme that attaches phosphate groups to other proteins. D) Cdk is inactive, or "turned off," in the presence of cyclin and it is present throughout the cell cycle. E) Cdk is present throughout the cell cycle and is an enzyme that attaches phosphate groups to other proteins. Answer: E 35) Besides the ability of some cancer cells to over proliferate, what else could logically result in a tumor? A) enhanced anchorage dependence B) changes in the order of cell cycle stages C) lack of appropriate cell death D) inability to form spindles E) inability of chromosomes to meet at the metaphase plate Answer: C 36) Why do neurons and some other specialized cells divide infrequently? A) They no longer have active nuclei. B) They no longer carry receptors for signal molecules. C) They have been shunted into G0. D) They can no longer bind Cdk to cyclin. E) They show a drop in MPF concentration. Answer: C 37) Which of the following most accurately describes a cyclin? A) It is present in similar concentrations throughout the cell cycle. B) It is activated to phosphorylate by complexing with a Cdk. C) It decreases in concentration when MPF activity increases. D) It activates a Cdk molecule when it is in sufficient concentration. E) It activates a Cdk when its concentration is decreased. Answer: D 38) All cell cycle checkpoints are similar in which way? A) They respond to the same cyclins. B) They utilize the same Cdks. C) They give the go-ahead signal to progress to the next checkpoint. D) They each have only one cyclin/Cdk complex. E) They activate or inactivate other proteins. Answer: C 39) At the M phase checkpoint, the complex allows for what to occur? A) Separase enzyme cleaves cohesins and allows chromatids to separate. B) Cohesins alter separase to allow chromatids to separate. C) Kinetochores are able to bind to spindle microtubules. D) All microtubules are made to bind to kinetochores. E) Daughter cells are allowed to pass into G1. Answer: A 40) Anchorage dependence of animal cells in vitro or in vivo depends on which of the following? A) attachment of spindle fibers to centrioles B) response of the cell cycle controls to signals from the plasma membrane C) the absence of an extracellular matrix D) the binding of cell-surface phospholipids to those of adjoining cells E) the binding of cell-surface phospholipids to the substrate Answer: B 41) Researchers began a study of a cultured cell line. Their preliminary observations showed them that the cell line did not exhibit either density-dependent inhibition or anchorage dependence. What could they conclude right away? A) The cells originated in the nervous system. B) The cells are unable to form spindle microtubules. C) The cells have altered series of cell cycle phases. D) The cells show characteristics of tumors. E) The cells were originally derived from an elderly organism. Answer: D 42) For a chemotherapeutic drug to be useful for treating cancer cells, which of the following is most desirable? A) It is safe enough to limit all apoptosis. B) It does not alter metabolically active cells. C) It only attacks cells that are density dependent. D) It interferes with cells entering G0. E) It interferes with rapidly dividing cells. Answer: E 43) You have a series of cells, all of which were derived from tumors, and you first need to find out which ones are malignant. What could you do? A) See which ones are not over proliferating. B) Find out which ones have a higher rate of apoptosis. C) Karyotype samples to look for unusual size and number of chromosomes. D) Measure metastasis. E) Time their cell cycles. Answer: C 9.2 Art Questions Use the following information to answer the questions below. The unlettered circle at the top of Figure 9.1 shows a diploid nucleus with four chromosomes that have not yet replicated. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is black, and the other is gray. The circles labeled A–E show various combinations of these chromosomes. Figure 9.1 1) What is the correct chromosomal condition for one daughter nucleus at telophase of mitosis? A) A B) B C) C D) D E) E Answer: E 2) What is the correct chromosomal condition for one daughter nucleus at telophase of mitosis? A) A B) B C) C D) D E) E Answer: E Figure 9.2 3) If the cell whose nuclear material is shown in Figure 9.2 continues toward completion of mitosis, which of the following events would occur next? A) cell membrane synthesis B) spindle fiber formation C) nuclear envelope breakdown D) formation of telophase nuclei E) synthesis of chromatids Answer: D The following questions are based on Figure 9.3. Figure 9.3 4) In Figure 9.3, mitosis is represented by which numbered part(s) of the cycle? A) I B) II C) III D) IV E) V Answer: D 5) G1 is represented by which numbered part(s) of the cycle? A) I or V B) II or IV C) III only D) IV only E) V only Answer: A 6) Which number represents DNA synthesis? A) I B) II C) III D) IV E) V Answer: B 7) Which number represents the point in the cell cycle during which the chromosomes are replicated? A) I B) II C) III D) IV E) V Answer: B 8) At which of the numbered regions would you expect to find cells at metaphase? A) I and IV B) II only C) III only D) IV only E) V only Answer: C 9) MPF reaches its threshold concentration at the end of this stage. A) I B) II C) III D) IV E) V Answer: C Use the data in Table 9.1 to answer the following questions. The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma. Table 9.1 Minutes Spent in Cell Cycle Phases 10) Of the following, the best conclusion concerning the difference between the S phases for beta and gamma is that A) gamma contains more DNA than beta. B) beta and gamma contain the same amount of DNA. C) beta cells reproduce asexually. D) gamma contains 48 times more DNA and RNA than beta. E) beta is a plant cell and gamma is an animal cell. Answer: A 11) The best conclusion concerning delta is that the cells A) contain no DNA. B) contain no RNA. C) contain only one chromosome that is very short. D) are actually in the G0 phase. E) divide in the G1 phase. Answer: D 9.3 Scenario Questions The following information applies to the questions below. Several organisms, primarily protists, have what are called intermediate mitotic organization. 1) These protists are intermediate in what sense? A) They reproduce by binary fission in their early stages of development and by mitosis when they are mature. B) They never coil up their chromosomes when they are dividing. C) They use mitotic division but only have circular chromosomes. D) They maintain a nuclear envelope during division. E) None of them form spindles. Answer: D 2) What is the most probable hypothesis about these intermediate forms of cell division? A) They represent a form of cell reproduction that must have evolved completely separately from those of other organisms. B) They demonstrate that these species are not closely related to any of the other protists and may well be a different kingdom. C) They rely on totally different proteins for the processes they undergo. D) They may be more closely related to plant forms that also have unusual mitosis. E) They show some but not all of the evolutionary steps toward complete mitosis. Answer: E Use the following information to answer the questions below. Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times. 3) Which of the following questions might be answered by such a method? A) How many cells are produced by the culture per hour? B) What is the length of the S phase of the cell cycle? C) When is the S chromosome synthesized? D) How many picograms of DNA are made per cell cycle? E) When do spindle fibers attach to chromosomes? Answer: B 4) The research team used the setup to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that A) the presence of the pathogen made the experiment too contaminated to trust the results. B) their tissue culture methods needed to be relearned. C) infection causes lymphocytes to divide more rapidly. D) infection causes cell cultures in general to reproduce more rapidly. E) infection causes lymphocyte cultures to skip some parts of the cell cycle. Answer: C 9.4 End-of-Chapter Questions 1) Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely A) an animal cell in the process of cytokinesis. B) a plant cell in the process of cytokinesis. C) an animal cell in the S phase of the cell cycle. D) a bacterial cell dividing. E) a plant cell in metaphase. Answer: B 2) In the cells of some organisms, mitosis occurs without cytokinesis. This will result in A) cells with more than one nucleus. B) cells that are unusually small. C) cells lacking nuclei. D) destruction of chromosomes. E) cell cycles lacking an S phase. Answer: A 3) Which of the following does not occur during mitosis? A) condensation of the chromosomes B) replication of the DNA C) separation of sister chromatids D) spindle formation E) separation of the spindle poles Answer: B 4) A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in A) G1. B) G2. C) prophase. D) metaphase. E) anaphase. Answer: A 5) The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B? A) spindle formation B) spindle attachment to kinetochores C) DNA synthesis D) cell elongation during anaphase E) cleavage furrow formation and cytokinesis Answer: E Test Bank for Campbell Biology in Focus Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson, Jane B. Reece 9780321813664, 9780321962751, 9780134710679
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