Chapter 10 Photosynthesis
18) 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
A
23) 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
A
26) Reduction of NADP+ occurs during A) photosynthesis. B) respiration. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration
A
37) 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
A
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
A
40) 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
A
44) 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
A
46) 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
A
54) 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
A
62) What wavelength of light in the figure is most effective in driving photosynthesis? A) 420 mm B) 475 mm C) 575 mm D) 625 mm E) 730 mm
A
74) If the power fails and the lights go dark, what will happen to CO2 levels? A) CO2 will rise as a result of both animal and plant respiration. B) CO2 will rise as a result of animal respiration only. C) CO2 will remain balanced because plants will continue to fix CO2 in the dark. D) CO2 will fall because plants will increase CO2 fixation. E) CO2 will fall because plants will cease to respire in the dark
A
10) In the thylakoid membranes, what is the main role of the antenna pigment molecules? A) split water and release oxygen to the reaction-center chlorophyll B) harvest photons and 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
B
13) 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
B
14) 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.
B
22) 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.
B
25) 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) photorespiration only.
B
29) 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
B
31) 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.
B
33) 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.
B
42) 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 is not part of photosynthesis
B
45) 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 is not part of photosynthesis
B
59) If atmospheric CO2 concentrations increase twofold or more, how will plants be affected, disregarding any changes in climate? 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.
B
69) 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. What color should she use 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
B
7) 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
B
8) 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
B
Figure 10.2 64) If the carbon atom of the incoming CO2 molecule 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
B
15) What are the products of linear photophosphorylation? A) heat and fluorescence B) ATP and P700 C) ATP and NADPH D) ADP and NADP E) P700 and P680
C
24) 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
C
28) Generation of proton gradients across membranes occurs during A) photosynthesis. B) respiration. C) both photosynthesis and respiration. D) neither photosynthesis nor respiration. E) photorespiration
C
38) The accumulation of free oxygen in Earth's atmosphere began A) with the origin of life and respiratory metabolism. B) with the origin of photosynthetic bacteria that had photosystem I. C) with the origin of cyanobacteria that had both photosystem I and photosystem II. D) with the origin of chloroplasts in photosynthetic eukaryotic algae. E) with the origin of land plants.
C
60) Plants photosynthesize only in the light. Plants respire A) in the dark only. B) in the light only. C) both in light and dark. D) never-they get their ATP from photophosphorylation. E) only when excessive light energy induces photorespiration
C
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. 73) 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? A) full-spectrum white light B) green light C) a mixture of blue and red light D) yellow light E) UV light
C
12) 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.
D
20) 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
D
27) 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
D
39) 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.
D
48) 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+
D
5) In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary? A) autotrophs and heterotrophs B) producers and primary consumers C) photosynthesizers D) autotrophs E) green plants
D
Figure 10.1 61) Figure 10.1 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.
D
Figure 10.2 63) 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
D
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. 71) An outcome of this experiment was to help determine A) the relationship between heterotrophic and autotrophic organisms. B) the relationship between wavelengths of light and the rate of aerobic respiration. C) the relationship between wavelengths of light and the amount of heat released. D) the relationship between wavelengths of light and the rate of photosynthesis. E) the relationship between the concentration of carbon dioxide and the rate of photosynthesis
D
11) Which of the events listed below 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.
E
2) 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
E
3) Photosynthesis is not responsible for A) oxygen in the atmosphere. B) the ozone layer. C) most of the organic carbon on Earth's surface. D) atmospheric CO2. E) fossil fuels.
E
41) 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
E