Chapter 7
Student: _________________________________________________________
1. What purpose is served by chlorophyll and other accessory pigments in plants?
A. Plant pigments absorb solar energy.
B. Chlorophyll provides electrons that will be used to produce ATP.
C. Chlorophyll contains the enzymes needed to produce carbohydrates.
D. Plant pigments are needed to absorb solar energy and provide electrons that will be used to produce ATP.
2. If plants were only able to undergo the cyclic pathway, which of the following would NOT be true?
A. Plants would not produce oxygen.
B. Carbohydrate could still be produced but in much smaller quantities.
C. More NADPH would be produced during the cyclic electron pathway.
D. ATP production would decrease due to a smaller amount of H+ being available.
3. If the Calvin cycle uses three molecules of CO2 to produce six molecules of G3P
(glyceraldehydes-3-phosphate), but only one G3P molecule is used to form a
carbohydrate molecule, what happens to the other carbons that were taken in?
A. Any unused CO2 is released into the environment.
B. The other five G3P molecules are used to regenerate more RuBP.
C. Any unused G3P molecule is converted and stored as starch.
D. The remaining five G3P molecules are used to reduce CO2.
4. What are the products of photosynthesis?
A. water and carbon dioxide
B. water and oxygen
C. oxygen and carbohydrate
D. carbohydrate and water
5. What organisms are capable of photosynthesis?
A. plants only
B. plants and algae only
C. plants and some bacteria only
D. plants, algae, and some bacteria
6. The action spectrum of photosynthesis shows a high light absorption for violet/blue and orange/red and a low
absorption for green/yellow. If we were to set up an experiment where narrow bands of unicolored light were
shown on an aquatic plant such as Elodea, and we counted the number of bubbles of oxygen produced as an
indicator of photosynthetic rate, how would the graph appear?
A. just like the action spectrum with peaks at violet/blue and orange/red and a trough at yellow/green
B. exactly inverted from the action spectrum with a peak for yellow/green
C. perfectly flat because many wavelengths are used by chlorophyll
D. a descending line because ultra-violet has more energy than infra-red
E. There is no way to guess without actually running the experiment.
7. When an electron has been excited to a higher energy state, it can then drop back to the original level, reemitting the light as fluorescence. When chlorophyll is extracted in solution, and a bright red or blue light is
shown on it, the chlorophyll fluoresces brightly. However, when the chlorophyll is packaged inside chloroplasts
and the red or blue light is turned on, there is no fluorescence. This most likely indicates that
A. the red and blue light waves are reflected by the chlorophyll membrane.
B. chlorophyll in solution is a different molecule than chlorophyll in a chloroplast.
C. excited electrons are transferred to electron acceptors in the chloroplast.
D. fluorescence does not work in living cells.
E. green light must be used to make living cells fluoresce.
8. Which of these is NOT a major photosynthetic pigment in plants?
A. chlorophyll a
B. chlorophyll b
C. chlorophyll c
D. carotenoid pigments
9. Why are plants green?
A. They absorb only green wavelengths of light.
B. They absorb only yellow and blue wavelengths of light.
C. They reflect nearly all wavelengths of light.
D. They reflect green wavelengths of light.
E. They reflect yellow and blue wavelengths of light.
10. An early experiment by Van Helmont (1600s) describes how he "grew a tree in a large pot and found that
after five years, the amount of soil in the pot had not changed. He concluded that the increase in weight was due
to the addition of water." At that time, the compounds in the air had not yet been identified. Today, you know
that he only discovered half the story. Which additional experiment would provide evidence for the rest of the
story?
A. A very careful audit of the water taken in and lost by the tree would have revealed only half the added
weight gained by the tree.
B. Carbon is discovered as a major element in trees and is lacking in water molecules.
C. Radioactive carbon in CO2 in the air is soon located as part of tree structures.
D. The critical experiment involves the conversion of nutrients in the soil.
E. All but the nutrient conversion is correct.
11. The term "chloroplast" is derived in part from the Greek root that means
A. plant.
B. light.
C. green.
D. photosynthetiC.
E. oxygen.
12. To what does the term stroma refer?
A. the double membrane of the chloroplast
B. a flattened disk or sac in the chloroplast
C. a stack of thylakoid membrane structures
D. the central fluid-filled space of the chloroplast
E. the cytochrome system in the membranes of the thylakoids
13. To what does the term grana refer?
A. the double membrane of the chloroplast
B. a flattened disk or sac in the chloroplast
C. a stack of thylakoid membrane structures
D. the central fluid-filled space of the chloroplast
E. the cytochrome system in the membranes of the thylakoids
14. The term derived from the Greek root that means "bed" or "mattress" is
A. strom A.
B. chloro.
C. gran A.
D. photos.
E. thylakoid.
15. The term derived from the Greek root that means "sack-like" is
A. strom A.
B. chloro.
C. gran A.
D. photos.
E. thylakoid.
16. Which of these is most closely associated with the process of electron transport?
A. the double membrane of the chloroplast
B. a flattened disk or sac in the chloroplast
C. a stack of thylakoid membrane structures
D. the central fluid-filled space of the chloroplast
E. the pigment complex in the membranes of the thylakoids
17. Although it is not possible to be exact about when cyanobacteria first appeared on earth, most scientists
agree that about two billion years ago, they expanded rapidly and raised the oxygen in the earth's atmosphere to
present levels in about 500 million years. This appearance of oxygen and the beginning of aerobic life was
made possible by the appearance of
A. fermentation.
B. Photosystem I.
C. Photosystem II.
D. ATP hydrolysis.
E. the nucleus.
18. Which statement is NOT true about photosystems?
A. Photosystem I passes electrons on to Photosystem II.
B. Each photosystem contains numerous pigment molecules that act as antennas to capture light.
C. Photosystem I contains a reaction center molecule that loses electrons which are then replaced by electrons
from water.
D. Electrons in the reaction center molecule are excited by absorbed solar energy and are passed along to an
acceptor molecule.
19. Protons (H+) accumulate in the thylakoid space during electron transport between photosystems I and II.
The excess of protons in the thylakoid space
A. enters the photorespiration pathway.
B. converts NADP to NADPH and generates ATP in the process.
C. is small enough to diffuse back out through the lipid bilayer.
D. raises the pH of the space until the processes stop.
E. moves from the thylakoid space to the stroma through an ATP synthase complex channel that generates ATP.
20. Which statement is NOT true about the cyclic electron pathway?
A. It produces ATP.
B. It involves Photosystem I.
C. It produces NADPH.
D. Electrons lost from Photosystem I eventually return to Photosystem I.
21. Which statement is NOT true about the noncyclic electron pathway?
A. Electrons are boosted to higher energy level in Photosystem I.
B. Sunlight excites electrons in Photosystem II.
C. It produces ATP.
D. It produces NADPH.
E. It produces carbohydrates through carbon dioxide fixation.
22. Which is NOT true about photosynthesis?
A. In noncyclic photophosphorylation, water is split and oxygen is released.
B. Photosystem II makes noncyclic photophosphorylation more efficient than does cyclic
photophosphorylation.
C. The cyclic system is used when there is insufficient NADP+ present to absorb electrons in plant cells.
D. More carbohydrate is produced during cyclic photophosphorylation than during noncyclic
photophosphorylation.
23. Which is most closely associated with the Calvin cycle?
A. ATP production
B. oxygen production
C. carbon dioxide fixation
D. carbon dioxide production
E. removal of electrons from water for passage through an electron transport system
24. The end product of the Calvin cycle is
A. ATP.
B. ribulose bisphosphate (RuBP).
C. glyceraldehyde-3-phospate (G3P).
D. PEP carboxylase (PEPcase).
E. carbon dioxide.
25. When the stomata in a leaf close, then
A. carbon dioxide in the air spaces in the leaf decreases.
B. oxygen in the air spaces in the leaf increases.
C. C3 plants carry on photorespiration, using O2 and producing PGA and CO2.
D. all photosystems as well as photorespiration come to a halt.
E. All choices but the halting of photosystems are correct.
26. The major enzyme that catalyzes the reduction of carbon dioxide is called
A. ribulose bisphosphate carboxylase (rubisco).
B. glyceraldehyde-3-phospate (G3P).
C. PEP carboxylase (PEPcase).
27. The first event in the Calvin cycle is the attachment of carbon dioxide to the five-carbon RuBP molecule,
which
A. forms a six-carbon molecule that immediately breaks down into two three-carbon PGA molecules.
B. is a reaction assisted by large quantities of RuBP carboxylase enzyme.
C. decreases cell carbon dioxide levels, which increases the diffusion gradient.
D. immediately becomes a six-carbon sugar that is the base for starch, sucrose, cellulose, etc.
E. All of the choices except the formation of a 6-C sugar used for starch, etc., are correct.
28. Most food plants, such as wheat, oats, and rice, are in the group of
A. CAM plants.
B. C3 plants.
C. C4 plants.
29. Which statement is NOT true about C3 and C4 plants?
A. C3 plants are more successful in mild climates than C4 plants.
B. C4 plants contain chloroplasts only in part of their mesophyll cells.
C. C3 plants fix CO2 in the mesophyll cells.
D. C3 plants make glucose in the bundle sheath cells.
E. The first CO2 fixation product in a C4 plant is oxaloacetate.
30. Photorespiration is a form of
A. fixation of carbon dioxide in C4 plants.
B. fixation of carbon dioxide in C3 plants.
C. release of carbon dioxide in C4 plants.
D. release of carbon dioxide in C3 plants.
31. Which would be a CAM plant?
A. cactus
B. corn
C. rice
D. wheat
E. oak tree
32. Carbon dioxide movement into a plant leaf involves all of the following EXCEPT
A. stomata.
B. diffusion.
C. electron transport systems.
D. air.
33. Photosynthetic pigments
A. absorb specific wavelengths of light in their absorption spectra.
B. include chlorophyll a, b, and the carotenoids.
C. have their absorption spectra analyzed using a spectrophotometer.
D. All of the choices are correct.
34. Oxygen production in photosynthesis involves all of the following EXCEPT
A. photosystem one.
B. photosystem two.
C. splitting of water.
D. All of the choices are associated with this process.
35. The Calvin cycle requires all of the following except _____________ to occur.
A. ATP, NADPH
B. carbon dioxide
C. light
D. ribulose bi-phosphate
36. G3P (glyceraldehyde 3 phosphate) is used by plants for all of the following EXCEPT the formation of
A. fatty acids.
B. amino acids.
C. oxygen.
D. sucrose.
37. C-4 plants
A. store carbon dioxide temporarily as oxaloacetate.
B. are found in hot dry climates.
C. have a net photosynthetic rate two to three times that of C-3 plants.
D. All of the choices are correct.
38. While C-4 plants have carbon dioxide fixation and carbon dioxide uptake separated by location within the
the plant, CAM plants
A. have these processes separated by time.
B. fix much greater amounts of carbon dioxide than C-4 plants.
C. are found in tropical regions where nutrients are abundant.
D. All of the choices are correct.
39. During photorespiration, oxygen is used by a plant to breakdown a carbohydrate and release oxygen.
True False
40. The ultimate source of energy for all organisms is the sun and the main source of the oxygen we breathe
from our environment is water.
True False
41. Fossil fuels are full of energy stored from photosynthesis millions of years ago.
True False
42. Only portions of visible light can be taken up by chlorophyll.
True False
43. Chlorophyll b is the pigment most involved in the reaction centers of photosystems.
True False
44. The light-dependent reactions of photosynthesis occur in the stroma of the chloroplast.
True False
45. Light-dependent reactions occur after light-independent reactions in the process of photosynthesis.
True False
46. The first part of the noncyclic electron pathway involves the removal of electrons from water.
True False
47. Some bacteria use noncyclic photophosphorylation, which does not produce oxygen or split water
molecules.
True False
48. Chemiosmotic ATP synthesis occurs in the cytosol of the cell.
True False
49. The enzyme complex called ATP synthetase is located in the thylakoid membranes.
True False
50. Carbon dioxide first binds to a five-carbon molecule, forming a six-carbon molecule that splits to form two
three-carbon molecules.
True False
51. Photorespiration is the process by which light is used to release the stored energy in carbohydrate molecules
to perform all work in plant cells.
True False
52. Plants that conduct C-4 metabolism are desert plants.
True False
53. The light independent reactions of the Calvin cycle occur in the thylakoids.
True False
54. Phosphoenylpyruvate carboxylase fixes carbon dioxide to PEP to form oxaloacetate within mesophyll cells
of the C-4 plants.
True False
55. Describe the absorption spectrum and the portion of it that is used in photosynthesis.
56. Discuss why visible light is the only part of the spectrum that is used by plants in photosynthesis and by
humans in vision.
57. Explain why we see plants as green.
58. Describe the structure of a chloroplast.
59. Describe the two types of light-dependent reactions of photosynthesis.
60. Describe what occurs in the light-independent reactions of photosynthesis.
61. Describe the roles of ATP and NADPH in photosynthesis.
62. Correlate the relative efficiency of CAM, C3, and C4 plants in photosynthesis with the enzymatic systems
active in this process.
63. If the photosynthetic rate of C4 plants such as sugar cane, corn, and Bermuda grass is about two or three
times that of C3 plants–and both are substantially more productive than CAM plants–then why, over time, have
C4 plants not out-competed and eliminated C3 and CAM plants?
Chapter 7 KEY
1. C
2. C
3. B
4. C
5. D
6. A
7. C
8. C
9. D
10. E
11. C
12. D
13. C
14. A
15. E
16. E
17. C
18. A
19. E
20. C
21. E
22. D
23. C
24. C
25. E
26. A
27. E
28. B
29. D
30. D
31. A
32. C
33. D
34. A
35. C
36. C
37. D
38. A
39. FALSE
40. TRUE
41. TRUE
42. TRUE
43. FALSE
44. TRUE
45. FALSE
46. TRUE
47. FALSE
48. FALSE
49. TRUE
50. TRUE
51. FALSE
52. FALSE
53. FALSE
54. TRUE
55. Answers will vary.
56. Answers will vary.
57. Answers will vary.
58. Answers will vary.
59. Answers will vary.
60. Answers will vary.
61. Answers will vary.
62. Answers will vary.
63. Answers will vary.