front 1 1) Which of the following sequences correctly represents the flow of electrons during photosynthesis? A. H2O > NADPH > Calvin Cycle B. NADPH > Chlorophyll > Calvin Cycle C. NADPH > Electron transport chain > O2 D. NADPH > O2 > CO2 E. H20 > Photosystem 1 > Photosystem 2 | back 1 A |
front 2 2) Photosynthesis is a redox reaction. This means that H2O is _____ during the light reactions and CO2 is _____ during the Calvin cycle. A. Oxidized ... Reduced B. Reduced ... Reduced C. Consumed ... Consumed D. Consumed ... Reduced E. Reduced ... Oxidized | back 2 A |
front 3 3)What is the basic role of CO2 in photosynthesis? A. CO2 is fixed or incorporated into organic molecules. B. CO2 is taken in by plants as a form of inverse respiration, in which carbon dioxide is “breathed in” and oxygen is “breathed out.” C. CO2 is a source of electrons in the formation of organic molecules. D. O2 E. C08 | back 3 A |
front 4 4)Which of the following is a product of the light reactions of photosynthesis? A. Glyceraldehyde-3-phosphate B. High-energy photons C. Oxygen, ATP, and NADPH D. NADP+ and RuBP E. Water and CO2 | back 4 C |
front 5 5)When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by _____. A. Oxidizing glucose B. Fixing carbon C. Splitting water D. Breaking down ATP E. Removing them from NADPH | back 5 C |
front 6 6)C4 plants occur more commonly in desert conditions because _____. A. They store carbon by incorporating CO2 into organic acids that are later catabolized B. They produce water as a product of their photosynthetic pathways C. The stomata open at night and close in the day D. They can fix carbon at the lower CO2 concentrations that develop when the stomata are closed E. They produce carbon dioxide internally via photorespiration | back 6 D |
front 7 7)Carbon fixation involves the addition of carbon dioxide to _____. A. Rubisco B. G3P C. NADPH D. RuBP E. 3-PGA | back 7 D |
front 8 8)After 3-PGA is phosphorylated, it is reduced by _____. A. CO2 B. NADPH C. ATP D. ADP E. NADP+ | back 8 B |
front 9 9)How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose? A. 6 B. 2 C. 10 D. 4 E. 8 | back 9 A |
front 10 10)In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules? A. 1 B. 3 C. 2 D. 4 E. 5 | back 10 B |
front 11 11)Which term describes ATP production resulting from the capture of light energy by chlorophyll? A. Substrate-level phosphorylation B. Photophosphorylation C. Dephosphorylation D. Oxidative phosphorylation | back 11 B |
front 12 12)True or false? The chemiosmotic hypothesis states that the synthesis of ATP generates a proton gradient that leads to electron flow through an electron transport chain. A. TRUE B. FALSE C. Dephosphorylation D. Oxidative phosphorylation E. C02 | back 12 B |
front 13 13)According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis? A. Temperature gradient B. Osmotic gradient C. Electrons D. Proton gradient | back 13 D |
front 14 14)Which of the following particles can pass through the ATP synthase channel? A. ATP B. ADP C. Inorganic phosphate D. Protons | back 14 D |
front 15 15)True or false? The region of ATP synthase that catalyzes the production of ATP from ADP and inorganic phosphate spans the chloroplast membrane. A. True B. False C. Inorganic phosphate D. Protons E. C02 | back 15 B |
front 16 16)Chloroplast membrane vesicles are equilibrated in a simple solution of pH 5. The solution is then adjusted to pH 8. Which of the following conclusions can be drawn from these experimental conditions? A. ATP will be produced because the proton gradient favors proton movement through the ATP synthase channels. B. ATP will not be produced because there is no ADP and inorganic phosphate in the solution. C. The change in the solution's pH results in a gradient across the chloroplast membranes such that there is a lower concentration of protons inside the vesicles and a higher concentration outside. D. Protons will not diffuse toward the outside of the vesicles. | back 16 B |
front 17 17)_____ has a longer wavelength than _____. A. Yellow ... red B. Red ... green C. Violet ... blue D. Green ... yellow E. Blue ... green | back 17 B |
front 18 18)The overall function of the Calvin cycle is _____. A. Making sugar B. Producing carbon dioxide C. Capturing sunlight D. Splitting water E. Oxidizing glucose | back 18 A |
front 19 19)In mechanism, photophosphorylation is most similar to A. Reduction of NADP+. B. Carbon fixation. C. The Calvin cycle. D. Oxidative phosphorylation in cellular respiration. E. Substrate-level phosphorylation in glycolysis. | back 19 D |
front 20 20)Which of these phosphorylates ADP to make ATP? a. A b. D c. E d. C e. B | back 20 C |
front 21 21)_____ releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment. A. E B. C C. B D. D E. A | back 21 C |
front 22 22)_____ splits water into 1/2 O2, H+, and e- . A. B B. C C. A D. E E. D | back 22 C |
front 23 23)Energized electrons from ____ enter an electron transport chain and are then used to reduce NADP+. A. B B. E C. A D. C E. D | back 23 D |
front 24 24)Chlorophyll can be found in _____. A. B and C B. A and C C. A and B D. B and D E. B and E | back 24 B |
front 25 25)Which of these equations best summarizes photosynthesis? A. C6H12O6 + 6 O2 → 6 CO2 + 12 H2O B. H2O → 2 H+ + 1/2 O2 + 2e- C. 6 CO2 + 6 H2O → C6H12O6 + 6 O2 D. 6 CO2 + 6 O2 → C6H12O6 + 6 H2O E. C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy | back 25 C |
front 26 26)Where does the Calvin cycle occur? A. C B. E C. D D. B E. A | back 26 B |
front 27 27)The light reactions of photosynthesis use _____ and produce _____. A. Water ... NADPH B. NADPH ... oxygen C. Carbon dioxide ... oxygen D. NADPH ... NADP+ E. Carbon dioxide ... sugar | back 27 A |
front 28 28)Select the correct molecule that is the main product of the Calvin cycle. A. G3P B. NADPH C. Glucose D. O2 E. C02 | back 28 A |
front 29 29)In C3 plants the conservation of water promotes _____. A. A shift to C4 photosynthesis B. The light reactions C. The opening of stomata D. Photosynthesis E. Photorespiration | back 29 E |
front 30 30)In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells. A. Grana B. Thylakoids C. Cytoplasm D. Stomata E. Stroma | back 30 C |
front 31 31) C4 plants differ from C3 and CAM plants in that C4 plants _____. A. Use malic acid to transfer carbon dioxide to the Calvin cycle B. Transfer fixed carbon dioxide to cells in which the Calvin cycle occurs C. Are better adapted to wet conditions D. Open their stomata only at night E. Use PEP carboxylase to fix carbon dioxide | back 31 B |
front 32 32)How is photosynthesis similar in C4 plants and CAM plants? A. In both cases, rubisco is not used to fix carbon initially. B. Both types of plants make sugar without the Calvin cycle. C. In both cases, only photosystem I is used. D. Both types of plants make most of their sugar in the dark. E. In both cases, thylakoids are not involved in photosynthesis. | back 32 A |
front 33 33) The process of photosynthesis probably originated _____. A) in plants D) three separate times during evolution | back 33 B |
front 34 34) In autotrophic bacteria, where is chlorophyll located? A) in chloroplast membranes D) in the infolded plasma membrane | back 34 D |
front 35 35) Plants photosynthesize _____. B) only in the dark but respire only in the light C) only in the light but respire in light and dark D) and respire only in the light | back 35 C |
front 36 36)Early investigators thought the oxygen produced by photosynthetic
plants came from carbon dioxide. In fact, it comes from _____. C) air | back 36 A |
front 37 37) 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) glyceraldehyde 3-phosphate (G3P) C) ribulose bisphosphate (RuBP) D) O2 | back 37 D |
front 38 38) Every ecosystem must have _____. A) autotrophs and heterotrophs C) photosynthesizers D) autotrophs | back 38 D |
front 39 39) When oxygen is released as a result of photosynthesis, it is a direct by-product of _____. A) splitting water molecules D) the electron transfer system of photosystem II | back 39 A |
front 40 40) Which of the following statements is a correct distinction
between autotrophs and heterotrophs? C) Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. | back 40 C |
front 41 41) 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. What did Engelmann conclude about the congregation of bacteria in the red and blue areas? A) Bacteria congregated in these areas due to an increase in the
temperature of the red and blue light. C) Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths. D) Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis. | back 41 B |
front 42 42) 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. An outcome of Engelmann's experiment was to help determine the
relationship between _____. C) wavelengths of light and the rate of photosynthesis | back 42 C |
front 43 43) 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. Since the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. What wavelengths of light should be used to maximize plant growth
with a minimum of energy expenditure? C) a mixture of blue and red light | back 43 C |
front 44 44) 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. Since the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. Suppose a plant has a unique photosynthetic pigment and the leaves
of this plant appear to be reddish yellow. What wavelengths of visible
light are absorbed by this pigment? C) green and yellow | back 44 B |
front 45 45) 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 | back 45 C |
front 46 46) Why are there several structurally different pigments in the
reaction centers of photosystems? | back 46 B |
front 47 47) If pigments from a particular species of plant are extracted and
subjected to paper chromatography, which of the following is most
likely? B) Paper chromatography would separate the pigments from a particular plant into several bands. C) The isolated pigments would be some shade of green. | back 47 B |
front 48 48) In autumn, the leaves of deciduous trees change colors. This is
because chlorophyll is degraded and _____. C) water supply to the leaves has been reduced | back 48 A |
front 49 49) What event accompanies energy absorption by chlorophyll (or other
pigment molecules of the antenna complex)? C) Electrons are stripped from NADPH. | back 49 D |
front 50 50) The final electron acceptor associated with photosystem I is _____. A) oxygen D) NADPH | back 50 C |
front 51 51) The electrons of photosystem II are excited and transferred to
electron carriers. From which molecule or structure do the photosystem
II replacement electrons come? C) water | back 51 C |
front 52 52) In the thylakoid membranes, the pigment molecules in a light-harvesting complex _____. A) split water and release oxygen from the reaction-center
chlorophyll | back 52 B |
front 53 53) Which of the following are directly associated with photosystem
I? B) generation of molecular oxygen | back 53 A |
front 54 54) 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 to _____. A) determine if they have thylakoids in the chloroplasts C) test for CO2 fixation in the dark | back 54 B |
front 55 55) What are the products of linear electron flow? A) heat and fluorescence D) ADP and NADP+ | back 55 C |
front 56 56) As a research scientist, you measure the amount of ATP and NADPH
consumed by the Calvin cycle in 1 hour. You find that 30,000 molecules
of ATP were consumed, but only 20,000 molecules of NADPH were
consumed. Where did the extra ATP molecules come from? | back 56 C |
front 57 57) Assume a thylakoid is somehow punctured so that the interior of
the thylakoid is no longer separated from the stroma. This damage will
most directly affect the _____. C) synthesis of ATP D) reduction of NADP+ | back 57 C |
front 58 58) In a plant cell, where are the ATP synthase complexes located? A)
thylakoid membrane only D) thylakoid membrane and plasma membrane | back 58 C |
front 59 59) In mitochondria, chemiosmosis moves protons from the matrix into
the intermembrane space, whereas in chloroplasts, chemiosmosis moves
protons from the _____. C) intermembrane space to the matrix | back 59 B |
front 60 60) Which of the following statements best describes the relationship
between photosynthesis and respiration? C) Photosynthesis occurs only in plants; respiration occurs only in animals. D) Photosynthesis is catabolic; respiration is anabolic. | back 60 B |
front 61 61) In photosynthetic cells, synthesis of ATP by the chemiosmotic
mechanism occurs during _____. C) photosynthesis and respiration | back 61 C |
front 62 62) Carbon dioxide is split to form oxygen gas and carbon compounds _____. A) during photosynthesis D) in neither photosynthesis nor respiration | back 62 D |
front 63 63) What is the relationship between the wavelength of light and the
quantity of energy per photon? C) They are logarithmically related. | back 63 B |
front 64 64) P680+ is said to be the strongest biological oxidizing agent.
Given its function, why is this necessary? C) It transfers its electrons to reduce NADP+ to NADPH. | back 64 D |
front 65 65) Carotenoids are often found in foods that are considered to have
antioxidant properties in human nutrition. What related function do
they have in plants? 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. | back 65 D |
front 66 66) In a plant, the reactions that produce molecular oxygen (O2) take place in _____. A) the light reactions alone | back 66 A |
front 67 67) The accumulation of free oxygen in Earth's atmosphere began with the origin of _____. A) life and respiratory metabolism D) land plants | back 67 B |
front 68 68) In its mechanism, photophosphorylation is most similar to _____. A) substrate-level phosphorylation in glycolysis D) reduction of NADP+ | back 68 B |
front 69 69) Which process is most directly driven by light energy? B) carbon fixation in the stroma C) reduction of NADP+ molecules | back 69 D |
front 70 70) 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 use to reduce overall light energy but still maximize plant growth? A) green | back 70 B |
front 71 71) 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. The dissolved oxygen in the flask with algae will _____. A) always be higher D) be higher in the light, but lower in the dark | back 71 D |
front 72 72) Which of the following are products of the light reactions of
photosynthesis that are utilized in the Calvin cycle? B) H2O and O2 C) ADP, Pi, and NADP+ D) ATP and NADPH | back 72 D |
front 73 73) Where does the Calvin cycle take place? A) stroma of the chloroplast | back 73 A |
front 74 74) What is the primary function of the Calvin cycle? A) use NADPH to release carbon dioxide D) synthesize simple sugars from carbon dioxide | back 74 D |
front 75 75) 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? B) regeneration of ATP from ADP C) regeneration of RuBP D) regeneration of NADP+ | back 75 C |
front 76 76) Which of the following sequences correctly represents the flow of
electrons during photosynthesis? C) NADPH → chlorophyll → Calvin cycle | back 76 B |
front 77 77) Which of the following does NOT occur during the Calvin cycle? A) oxidation of NADPH D) consumption of ATP | back 77 B |
front 78 78) What compound provides the reducing power for Calvin cycle reactions? A) ATP C) NADP+ | back 78 D |
front 79 79) What would be the expected effect on plants if the atmospheric CO2 concentration was doubled? A) All plants would experience increased rates of
photosynthesis. C) C4 plants would have faster growth; C3 plants would be minimally affected. D) C3 plants would have faster growth; C4 plants would have slower growth. | back 79 B |
front 80 80) Why are C4 plants able to photosynthesize with no apparent photorespiration? A) They do not participate in the Calvin cycle. C) They conserve water more efficiently. | back 80 B |
front 81 81) CAM plants keep stomata closed in the daytime, thus reducing loss
of water. They can do this because they _____. C) fix CO2 into pyruvate in the mesophyll cells D) use photosystem I and photosystem II at night | back 81 A |
front 82 82) 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. C) Both minimize photorespiration but expend more ATP during
carbon fixation. | back 82 C |
front 83 83) If plant gene alterations cause plants to be deficient in
photorespiration, what would most probably occur? C) There would be more light-induced damage to the cells. D) Less oxygen would be produced. | back 83 C |
front 84 84) Compared to C3 plants, C4 plants _____. B) have higher rates of photorespiration | back 84 A |
front 85 85) Photorespiration _____. C) generates oxygen and consumes ATP, carbon dioxide, and sugars D) consumes carbon dioxide and generates ATP, sugars, and oxygen | back 85 A |
front 86 86) The figure 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) Oxygen given off during photosynthesis interferes with the absorption of light. C) Other pigments absorb light in addition to chlorophyll a. D) Aerobic bacteria take up oxygen, which changes the measurement of the rate of photosynthesis. | back 86 C |
front 87 87) What wavelength of light in the figure is most effective in driving photosynthesis? A) 420 mm B) 575 mm C) 625 mm D) 730 mm | back 87 A |
front 88 88) Refer to the figure. 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 | back 88 B |
front 89 89) Refer to the figure. 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? A) The CO2 acceptor concentration would decrease when either the CO2 or light are cut off. B) The CO2 acceptor concentration would increase when either the CO2 or light are 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. | back 89 C |
front 90 90) Which of the following statements is true concerning the accompanying figure? A) It represents a C4 photosynthetic system. B) It represents an adaptation that maximizes photorespiration. C) It represents a C3 photosynthetic system. D) It represents a CAM photosynthetic system. | back 90 A |
front 91 91) Referring to the accompanying figure, oxygen would inhibit the CO2 fixation reactions in _____. A) cell I only B) cell II only C) neither cell I nor cell II D) both cell I and cell II | back 91 B |
front 92 92) Photorespiration _____. A) generates carbon dioxide and consumes ATP and oxygen B) generates ATP and sugars and consumes oxygen and carbon dioxide C) generates oxygen and consumes ATP, carbon dioxide, and sugars D) consumes carbon dioxide and generates ATP, sugars, and oxygen | back 92 A |
front 93 93) As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find that 30,000 molecules of ATP were consumed, but only 20,000 molecules of NADPH were consumed. Where did the extra ATP molecules come from? A) photosystem II B) photosystem I C) cyclic electron flow D) linear electron flow | back 93 C |
front 94 94) What are the products of linear electron flow? A) heat and fluorescence B) ATP and P700 C) ATP and NADPH D) ADP and NADP+ | back 94 C |
front 95 95) As electrons are passed through the system of electron carriers associated with photosystem II, they lose energy. What happens to this energy? A) It excites electrons of the reaction center of photosystem I. B) It is lost as heat. C) It is used to establish and maintain a proton gradient. D) It is used to phosphorylate NAD+ to NADPH, the molecule that accepts electrons from photosystem I. | back 95 C |
front 96 96)The chemiosmotic process in chloroplasts involves the _____.
| back 96 A |
front 97 97) Suppose the interior of the thylakoids of isolated chloroplasts
were made acidic and then | back 97 A |
front 98 98) The pH of the inner thylakoid space has been measured, as have
the pH of the stroma and of | back 98 A |
front 99 99) In its mechanism, photophosphorylation is most similar to _____.
| back 99 B |
front 100 100) Which process is most directly driven by light energy? | back 100 D |
front 101 101)In plants, reduction of NADP+ occurs during _____. | back 101 A |