Bio Chapter 10
If plant gene alterations cause the plants to be deficient in photorespiration, what would most probably occur? A) There would be more light-induced damage to the cells. B) Cells would carry on the Calvin cycle at a much slower rate. C) Less oxygen would be produced. D) Less ATP would be generated. E) Photosynthetic efficiency would be reduced at low light intensities.
A) There would be more light-induced damage to the cells.
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? A) a mixture of blue and red light B) green light C) yellow light D) full-spectrum white light E) UV light
A) a mixture of blue and red light
In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary? A) autotrophs B) autotrophs and heterotrophs C) producers and primary consumers D) green plants E) photosynthesizers
A) autotrophs
Referring to the figure, oxygen would inhibit the CO2 fixation reactions in A) cell II only. B) both cell I and cell II. C) cell I during the night and cell II during the day. D) neither cell I nor cell II. E) cell I only.
A) cell II only.
Reduction of NADP+ occurs during A) photosynthesis. B) neither photosynthesis nor respiration. C) both photosynthesis and respiration. D) respiration.
A) photosynthesis.
When oxygen is released as a result of photosynthesis, it is a direct by-product of A) splitting water molecules. B) the electron transfer system of photosystem I. C) reducing NADP+. D) chemiosmosis. E) the electron transfer system of photosystem II.
A) splitting water molecules.
Use the following figure and the compounds labeled A, B, C, D, and E to answer the following question. 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 and C only B) B and E only C) B, C, and D only D) B, C, D, and E E) B only
B) B and E only
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) O2. C) ribulose bisphosphate (RuBP). D) glyceraldehyde 3-phosphate (G3P). E) glucose.
B) O2.
Photorespiration occurs when rubisco reacts RuBP with A) glyceraldehyde 3-phosphate. B) O2. C) 3-phosphoglycerate. D) CO2. E) NADPH.
B) O2.
What is the relationship between wavelength of light and the quantity of energy per photon? A) They are separate phenomena. B) They are inversely related. C) They are logarithmically related. D) They are only related in certain parts of the spectrum. E) They have a direct, linear relationship.
B) They are inversely related.
Plants photosynthesize only in the light. Plants respire A) in the dark only. B) both in light and dark. C) only when excessive light energy induces photorespiration. D) never-they get their ATP from photophosphorylation. E) in the light only.
B) both in light and dark.
In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during A) photosynthesis only. B) both photosynthesis and respiration. C) neither photosynthesis nor respiration. D) photorespiration only. E) respiration only.
B) both photosynthesis and respiration.
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 are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths. 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 congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis. E) Bacteria released excess carbon dioxide in these areas.
C) Bacteria congregated in these areas because these areas had the most oxygen being released.
What would be the expected effect on plants if the atmospheric CO2 concentration was doubled? A) C3 plants will have faster growth; C4 plants will have slower growth. B) C4 plants will have faster growth; C3 plants will be minimally affected. C) C3 plants will have faster growth; C4 plants will be minimally affected. D) Plant growth will not be affected because atmospheric CO2 concentrations are never limiting for plant growth. E) All plants will experience increased rates of photosynthesis.
C) C3 plants will have faster growth; C4 plants will be minimally affected.
In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best characterized as a A) C3 plant. B) CAM plant. C) C4 plant. D) heterotroph. E) chemoautotroph.
C) C4 plant.
The figure shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different? A) Aerobic bacteria take up oxygen, which changes the measurement of the rate of photosynthesis. B) Bright sunlight destroys photosynthetic pigments. C) Other pigments absorb light in addition to chlorophyll a. D) Oxygen given off during photosynthesis interferes with the absorption of light. E) Green and yellow wavelengths inhibit the absorption of red and blue wavelengths.
C) Other pigments absorb light in addition to chlorophyll a.
The phylogenetic distribution of the enzyme rubisco is limited to A) C3 and C4 plants. B) C3 plants only. C) all known photoautotrophs, both bacterial and eukaryotic. D) all photosynthetic eukaryotes. E) all living cells.
C) all known photoautotrophs, both bacterial and eukaryotic.
Photorespiration lowers the efficiency of photosynthesis by A) consuming carbon dioxide. B) denaturing rubisco. C) reducing the amount of 3-phosphoglycerate forme. D) producing ribulose bisphosphate. E) generating excess ATP.
C) reducing the amount of 3-phosphoglycerate forme.
What wavelength of light in the figure is most effective in driving photosynthesis? A) 475 mm B) 730 mm C) 625 mm D) 420 mm E) 575 mm
D) 420 mm
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 has a positive charge. 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 is the molecule that transfers electrons to plastoquinone (Pq) of the electron transfer system.
D) It obtains electrons from the oxygen atom in a water molecule, so it must have a stronger attraction for electrons than oxygen has.
What compound provides the reducing power for the Calvin cycle reactions? A) NAD+ B) NADP+ C) ATP D) NADPH E) NADH
D) NADPH
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 shield the sensitive chromosomes of the plant from harmful ultraviolet radiation. B) They reflect orange light and enhance red light absorption by chlorophyll. C) They take up and remove toxins from the groundwater. D) They protect against oxidative damage from excessive light energy. E) They serve as accessory pigments to increase light absorption.
D) They protect against oxidative damage from excessive light energy.
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) blue, green, and red B) green, blue, and yellow C) red and yellow D) blue and violet E) green and yellow
D) blue and violet
Generation of proton gradients across membranes occurs during A) neither photosynthesis nor respiration. B) respiration. C) photorespiration. D) both photosynthesis and respiration. E) photosynthesis.
D) both photosynthesis and respiration.
Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes? A) the splitting of water B) the flow of electrons from photosystem II to photosystem I C) the absorption of light energy by chlorophyll D) the synthesis of ATP E) the reduction of NADP+
D) the synthesis of ATP
What are the products of linear electron flow? A) heat and fluorescence B) P700 and P680 C) ADP and NADP+ D) ATP and P700 E) ATP and NADPH
E) ATP and NADPH
Use the following figure and the compounds labeled A, B, C, D, and E to answer the following question. 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, D, and E only B) B and C only C) C only D) B and D only E) B, C, D, and E
E) B, C, D, and E
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? A) ATP and NADPH B) ADP, i, and NADP+ C) electrons and H+ D) H2O and O2 E) CO2 and glucose
A) ATP and NADPH
Use the following figure and the compounds labeled A, B, C, D, and E to answer the following question. Which molecule(s) of the Calvin cycle is (are) also found in glycolysis? A) B, C, D, and 3-phosphoglycerate only B) 3-phosphoglycerate only C) B, C, and E only D) B, C, E, and 3-phosphoglycerate E) E only
A) B, C, D, and 3-phosphoglycerate only
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. 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 fall because plants will cease to respire in the dark. C) CO2 will fall because plants will increase CO2 fixation. D) CO2 will remain balanced because plants will continue to fix CO2 in the dark. E) CO2 will rise as a result of animal respiration only.
A) CO2 will rise as a result of both animal and plant respiration.
Use the following figure and the compounds labeled A, B, C, D, and E to answer the following question. 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 the figure to help you in determining the correct answer. A) The CO2 acceptor concentration would increase when the CO2 is cut off, but decrease when the light is cut off. B) The CO2 acceptor concentration would decrease when the CO2 is cut off, but increase when the light is cut off. C) The CO2 acceptor concentration would increase when either the CO2 or light are cut off. D) The CO2 acceptor concentration would stay the same regardless of the CO2 or light. E) The CO2 acceptor concentration would decrease when either the CO2 or light are cut off.
A) The CO2 acceptor concentration would increase when the CO2 is cut off, but decrease when the light is cut off.
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 supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. C) There is no relationship between the light reactions and the Calvin cycle. D) 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. E) The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split.
A) The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, i, and NADP+ to the light reactions.
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) both oxidize and reduce during electron transport B) transport protons within the mitochondria and chloroplasts C) act as oxidizing agents D) donate electrons E) act as reducing agents
A) both oxidize and reduce during electron transport
What does the chemiosmotic process in chloroplasts involve? A) establishment of a proton gradient across the thylakoid membrane B) movement of water by osmosis into the thylakoid space from the stroma C) diffusion of electrons through the thylakoid membrane D) formation of glucose, using carbon dioxide, NADPH, and ATP E) reduction of water to produce ATP energy
A) establishment of a proton gradient across the thylakoid membrane
In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from A) the stroma to the thylakoid space. B) the matrix to the stroma. C) the intermembrane space to the matrix. D) the stroma to the photosystem II. E) the thylakoid space to the stroma.
A) the stroma to the thylakoid space.
Where are the molecules of the electron transport chain found in plant cells? A) thylakoid membranes of chloroplasts B) outer membrane of mitochondria C) cytoplasm D) stroma of chloroplasts E) matrix of mitochondria
A) thylakoid membranes of chloroplasts
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) ATP molecules are produced in photosynthesis and used up in respiration. D) Respiration is anabolic and photosynthesis is catabolic. E) Photosynthesis occurs only in plants and respiration occurs only in animals.
B) Photosynthesis stores energy in complex organic molecules, whereas respiration releases it.
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. If you ran the same experiment without passing light through a prism, what would you predict? A) The number of bacteria present would increase due to an increase in the carbon dioxide concentration. 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) There would be no difference in results. E) The number of bacteria would decrease due to a decrease in the temperature of the water.
B) The bacteria would be relatively evenly distributed along the algal filaments.
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 be higher in the light, but the same in the dark. B) The dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark. C) The dissolved oxygen in the flask with algae will not be different from the control flask at any time. D) The dissolved oxygen in the flask with algae will always be higher. E) The dissolved oxygen in the flask with algae will always be lower.
B) The dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark.
Which statement describes the functioning of photosystem II? A) Light energy excites electrons in the thylakoid membrane electron transport chain. B) The electron vacancies in P680+ are filled by electrons derived from water. C) The P680 chlorophyll donates a pair of protons to NADP+, which is thus converted to NADPH. D) The splitting of water yields molecular carbon dioxide as a by-product. E) Photons are passed along to a reaction-center chlorophyll.
B) The electron vacancies in P680+ are filled by electrons derived from water.
Compared to C3 plants, C4 plants A) grow better under cool, moist conditions. B) can continue to fix CO2 even at relatively low CO2 concentrations and high oxygen concentrations. C) have higher rates of photorespiration. D) make a four-carbon compound, oxaloacetate, which is then delivered to the citric acid cycle in mitochondria. E) do not use rubisco for carbon fixation.
B) can continue to fix CO2 even at relatively low CO2 concentrations and high oxygen concentrations.
CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they A) fix CO2 into pyruvate in the mesophyll cells. B) fix CO2 into organic acids during the night. C) fix CO2 into sugars in the bundle-sheath cells. D) use the enzyme phosphofructokinase, which outcompetes rubisco for CO2. E) use photosystem I and photosystem II at night.
B) fix CO2 into organic acids during the night.
The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during A) respiration. B) neither photosynthesis nor respiration. C) both photosynthesis and respiration. D) photosynthesis. E) photorespiration.
B) neither photosynthesis nor respiration.
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 pigment molecules of photosystem I and photosystem II. B) on the stromal side of the membrane. C) on the ATP molecules themselves. D) on the side facing the thylakoid space. E) built into the center of the thylakoid stack (granum).
B) on the stromal side of the membrane.
The NADPH required for the Calvin cycle comes from A) oxidative phosphorylation. B) reactions initiated in photosystem I. C) reactions initiated in photosystem II. D) the citric acid cycle. E) glycolysis.
B) reactions initiated in photosystem I.
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) regeneration of ATP from ADP B) regeneration of RuBP C) inactivation of RuBP carboxylase enzyme D) addition of a pair of electrons from NADPH E) regeneration of NADP+
B) regeneration of RuBP
Reduction of oxygen to form water occurs during A) photosynthesis only. B) respiration only. C) the dark reactions only. D) both photosynthesis and respiration. E) neither photosynthesis nor respiration.
B) respiration only.
Where does the Calvin cycle take place? A) cytoplasm surrounding the chloroplast B) stroma of the chloroplast C) interior of the thylakoid (thylakoid space) D) outer membrane of the chloroplast E) thylakoid membrane
B) stroma of the chloroplast
The reactions that produce molecular oxygen (O2) take place in A) both the light reactions and the Calvin cycle. B) the light reactions alone. C) the chloroplast, but are not part of photosynthesis. D) neither the light reactions nor the Calvin cycle. E) the Calvin cycle alone.
B) the light reactions alone.
In a plant cell, where are the ATP synthase complexes located? A) thylakoid membrane only B) thylakoid membrane and inner mitochondrial membrane C) inner mitochondrial membrane only D) thylakoid membrane and plasma membrane E) plasma membrane only
B) thylakoid membrane and inner mitochondrial membrane
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 test for CO2 fixation in the dark. B) to test for liberation of O2 in the light. C) to test for production of either sucrose or starch. D) to do experiments to generate an action spectrum. E) to determine if they have thylakoids in the chloroplasts.
B) to test for liberation of O2 in the light.
Cyclic electron flow may be photoprotective (protective to light-induced damage). Which of the following experiments could best provide information on this phenomenon? A) use bacteria that have only cyclic flow and look for their frequency of mutation damage at different light intensities B) use mutated organisms that can grow but that cannot carry out cyclic flow of electrons and compare their abilities to photosynthesize in different light intensities against those of wild-type organisms C) use bacteria with only cyclic flow and measure the number and types of photosynthetic pigments they have in their membranes D) use plants with only photosystem I operative and measure how much damage occurs at different wavelengths E) use plants that can carry out both linear and cyclic electron flow, or only one or another of these processes, and compare their light absorbance at different wavelengths and different light intensities
B) use mutated organisms that can grow but that cannot carry out cyclic flow of electrons and compare their abilities to photosynthesize in different light intensities against those of wild-type organisms
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) Photosystem II may have evolved to be more photoprotective. C) Photosynthesis with only photosystem I is more ancestral. D) Cyclic flow is more necessary than linear electron flow. E) Linear electron flow is more primitive than cyclic flow of electrons.
C) Photosynthesis with only photosystem I is more ancestral.
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 reduce NADP+ to NADPH. B) The Calvin cycle will be activated. C) The isolated chloroplasts will make ATP. D) The isolated chloroplasts will generate oxygen gas. E) Cyclic photophosphorylation will occur.
C) The isolated chloroplasts will make ATP.
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) blue, green, and red B) red and yellow C) green and yellow D) red and green E) blue and red
C) green and yellow
Where do the enzymatic reactions of the Calvin cycle take place? A) matrix of the mitochondria B) thylakoid membranes C) stroma of the chloroplast D) cytosol around the chloroplast E) thylakoid space
C) stroma of the chloroplast
Reactions that require CO2 take place in A) the light reactions alone. B) the chloroplast, but is not part of photosynthesis. C) the Calvin cycle alone. D) neither the light reactions nor the Calvin cycle. E) both the light reactions and the Calvin cycle.
C) the Calvin cycle alone.
In a cyanobacterium, the reactions that produce NADPH occur in A) the Calvin cycle alone. B) the chloroplast, but is not part of photosynthesis. C) the light reactions alone. D) neither the light reactions nor the Calvin cycle. E) both the light reactions and the Calvin cycle.
C) the light reactions alone.
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 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 rate of photosynthesis. D) the relationship between wavelengths of light and the amount of heat released. E) the relationship between the concentration of carbon dioxide and the rate of photosynthesis.
C) the relationship between wavelengths of light and the rate of photosynthesis.
Students conducted an experiment to determine the effect of light intensity on the rate of photosynthesis. They punched 40 leaf disks from spinach leaves and used a syringe partially filled with water to pull the gases from the leaf disks so that all leaf disks sunk to the bottom of the syringe. Ten (10) leaf disks from the syringe were placed in each of four cups and covered with 50 ml of the solutions as indicated below. All leaf disks were resting on the bottom of the cups when the experiment began. The volume of liquid in each cup and the temperature of the solutions were held constant. All cups were placed 0.5 meters from the designated light source. A large beaker of water was placed between the light and the cups to act as a heat sink to prevent a change in temperature. At the end of 10 minutes, the number of disks floating in each cup was recorded. Use your knowledge of the mechanism of photosynthesis and the data presented in the chart to determine which of the statements below is a correct explanation for the student's data. A) Cup 2 had the highest rate of photosynthesis because 5 disks were floating at the end of 10 minutes using a 50 watt light bulb. B) Cup 1 had a low rate of photosynthesis because 0.5 grams of baking soda did not provide a sufficient amount of CO2. C) Cup 3 had the same rate of photosynthesis as Cup 1 because they had the same ratio of disks floating to wattage of light. D) Cup 4 had the slowest rate of photosynthesis because it had the least baking soda.
D) Cup 4 had the slowest rate of photosynthesis because it had the least baking soda.
Why are C4 plants able to photosynthesize with no apparent photorespiration? A) They do not participate in the Calvin cycle. B) They conserve water more efficiently. C) They are adapted to cold, wet climates. D) They use PEP carboxylase to initially fix CO2. E) They exclude oxygen from their tissues.
D) They use PEP carboxylase to initially fix CO2.
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) linear electron flow C) chlorophyll D) cyclic electron flow E) photosystem I
D) cyclic electron flow
In autotrophic bacteria, where is chlorophyll located? A) in chloroplast stroma B) in the nucleoid C) in the ribosomes D) in the infolded plasma membrane E) in chloroplast membranes
D) in the infolded plasma membrane
Which of the following are directly associated with photosystem I? A) passing electrons to the thylakoid membrane electron transport chain B) extraction of hydrogen electrons from the splitting of water C) harvesting of light energy by ATP D) receiving electrons from the thylakoid membrane electron transport chain E) generation of molecular oxygen
D) receiving electrons from the thylakoid membrane electron transport chain
What is the primary function of the Calvin cycle? A) use NADPH to release carbon dioxide B) split water and release oxygen C) transport RuBP out of the chloroplast D) synthesize simple sugars from carbon dioxide E) use ATP to release carbon dioxide
D) synthesize simple sugars from carbon dioxide
In the thylakoid membranes, what is the main role of the pigment molecules in a light-harvesting complex? A) concentrate photons within the stroma B) split water and release oxygen to the reaction-center chlorophyll C) synthesize ATP from ADP and i D) transfer light energy to the reaction-center chlorophyll E) transfer electrons to ferredoxin and then NADPH
D) transfer light energy to the reaction-center chlorophyll
The accumulation of free oxygen in Earth's atmosphere began A) with the origin of photosynthetic bacteria that had photosystem I. B) with the origin of chloroplasts in photosynthetic eukaryotic algae. C) with the origin of land plants. D) with the origin of cyanobacteria that had both photosystem I and photosystem II. E) with the origin of life and respiratory metabolism.
D) with the origin of cyanobacteria that had both photosystem I and photosystem II.
The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why? A) CAM plants allow more water loss, while C4 plants allow less CO2 into the plant. B) C4 compromises on water loss and CAM compromises on photorespiration. C) C4 plants allow less water loss but CAM plants allow more water loss. D) Each one minimizes both water loss and rate of photosynthesis. E) Both minimize photorespiration but expend more ATP during carbon fixation.
E) Both minimize photorespiration but expend more ATP during carbon fixation.
Which of the following statements is true concerning the figure? A) It represents a relationship between plant cells that photosynthesize and those that cannot. 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 cell processes involved in C4 photosynthesis.
E) It represents cell processes involved in C4 photosynthesis.
Which of the events listed below occurs in the light reactions of photosynthesis? A) Carbon dioxide is incorporated into PGA. B) ATP is phosphorylated to yield ADP. C) NADPH is reduced to NADP+. D) NADP is produced. E) Light is absorbed and funneled to reaction-center chlorophyll a.
E) Light is absorbed and funneled to reaction-center chlorophyll a.
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 of the stroma is lower than that of the other two measurements. B) There is no consistent relationship. 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) The pH within the thylakoid is less than that of the stroma.
E) The pH within the thylakoid is less than that of the stroma.
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) any color will work equally well B) orange C) green D) yellow E) blue
E) blue
In C3 photosynthesis, the reactions that require ATP take place in A) the chloroplast, but is not part of photosynthesis. B) both the light reactions and the Calvin cycle. C) the light reactions alone. D) neither the light reactions nor the Calvin cycle. E) the Calvin cycle alone.
E) the Calvin cycle alone.
