becker's world of the cell ch 11
Recently, Livingston et al. ( The Plant Cell 22: 221, 2010) isolated an Arabidopsis thaliana mutant with unusually high cyclic electron flow (hcef). See if you can predict the results they observed when comparing the hcef mutant plants with normal Arabidopsis plants. A. The light-driven proton flux increases as more of the excited electrons from PSI are used in cyclic electron flow to pump protons into the thylakoid lumen. B. The light-driven proton flux remains unchanged as more of the excited electrons from PSI are used in cyclic electron flow to pump protons into the thylakoid lumen. C. The light-driven proton flux stops as more of the excited electrons from PSI are used in cyclic electron flow to pump protons into the thylakoid lumen. D. The light-driven proton flux decreases as more of the excited electrons from PSI are used in cyclic electron flow to pump protons into the thylakoid lumen.
A
https://session.masteringbiology.com/problemAsset/2282322/1/MB_1321574_001.jpg Approximately what wavelength of light is best absorbed by chlorophyll a, the pigment that participates directly in the light reactions? A. 435 nm B. 525 nm C. 680 nm D. One cannot tell from this graph.
A
What is the biological significance of the light-independent reactions of photosynthesis? A. They convert carbon dioxide to sugar. B. They make oxygen. C. They generate ATP and NADPH. D. They convert ATP to sugar.
A (All organisms use the sugars produced by photosynthesis to generate energy.)
What is the importance of the light-independent reactions in terms of carbon flow in the biosphere? A. The light-independent reactions turn CO2, a gas, into usable carbon in the form of sugars. B. The light-independent reactions turn sugar into ATP for energy. C. The light-independent reactions turn glucose, a sugar, into CO2 gas. D. The light-independent reactions use CO2 to make ATP.
A (CO2 is unusable until plants have "fixed" this carbon into sugar.)
Which of the following reactions ensures that the Calvin cycle can make a continuous supply of glucose? A. Regneration of RuBP B. Carbon fixation C. Production of G3P D. Production of 3-phosphoglycerate
A (The regeneration of RuBP ensures that the Calvin cycle can proceed indefinitely, since RuBP fixes carbon dioxide into an organic molecule that is used to produce sugar.)
A Crassulacean Acid Metabolism (CAM) plant uses a pathway very similar to the Hatch-Slack cycle for preliminary carbon dioxide fixation. How does this minimize water loss by such plants? A. CAM plants are able to fix CO2 and accumulate carbon in the form of organic acids during the night, when the loss of water through closed stomata thereby is minimized. During the day, when solar energy is available, CAM plants open their stomata and channel carbon from malate into the Calvin cycle. B. CAM plants are able to fix CO2 and accumulate carbon in the form of organic acids during the night, when the loss of water through open stomata thereby is minimized. During the day, when solar energy is available but the potential for water loss is highest, CAM plants close their stomata and channel carbon from malate into the Calvin cycle. C. CAM plants are able to fix CO2 and accumulate carbon in the form of organic acids during the day, when solar energy is available and when the loss of water through open stomata is minimized. During the night, when the potential for water loss is highest, CAM plants close their stomata and channel carbon from malate into the Calvin cycle. D. CAM plants are able to fix CO2 and accumulate carbon in the form of organic acids during the day, when solar energy is available and when the loss of water through closed stomata is minimized. During the night, when the potential for water loss is highest, CAM plants open their stomata and channel carbon from malate into the Calvin cycle.
B
Recently, Livingston et al. ( The Plant Cell 22: 221, 2010) isolated an Arabidopsis thaliana mutant with unusually high cyclic electron flow (hcef). See if you can predict the results they observed when comparing the hcef mutant plants with normal Arabidopsis plants. How was noncyclic electron flow affected in hcef mutant plants? A. Noncyclic electron flow in hcef mutant plants is increased compared to normal plants. B. Noncyclic electron flow in hcef mutant plants is decreased compared to normal plants. C. Noncyclic electron flow in hcef mutant plants does not occur. D. Noncyclic electron flow in hcef mutant plants is the same as in normal plants.
B
Recently, Livingston et al. ( The Plant Cell 22: 221, 2010) isolated an Arabidopsis thaliana mutant with unusually high cyclic electron flow (hcef). See if you can predict the results they observed when comparing the hcef mutant plants with normal Arabidopsis plants. How was the activity of affected? A. PSII activity was decreased because the altered electron flow happened before electrons had left PSII. B. PSII activity was not affected because the altered electron flow happened after electrons had left PSII. C. PSII activity was decreased because the altered electron flow happened after electrons had left PSII. D. PSII activity was increased because the altered electron flow happened before electrons had left PSII.
B
Recently, Livingston et al. ( The Plant Cell 22: 221, 2010) isolated an Arabidopsis thaliana mutant with unusually high cyclic electron flow (hcef). See if you can predict the results they observed when comparing the hcef mutant plants with normal Arabidopsis plants. What would you predict is the effect on starch synthesis in the stroma? A. Starch synthesis is likely to increase due to the reduced synthesis of glucose. B. Starch synthesis is likely to decrease due to the reduced synthesis of glucose. C. Starch synthesis is likely to increase due to the increased synthesis of glucose. D. Starch synthesis is likely to decrease due to the increased synthesis of glucose.
B
Which is the correct order of flow of electrons through the thylakoid membrane during energy transduction reactions? A. cytochrome complex, photosystem I, photosystem II B. photosystem II, cytochrome complex, photosystem I C. photosystem II, photosystem I, cytochrome complex D. cytochrome complex, photosystem II, photosystem I
B
Which of the following molecules is the primary product of photosystem I? A. Oxygen B. NADPH C. ATP D. Carbon dioxide
B
Which of these wavelengths/colors of visible light is LEAST useful for photosynthesis? A. yellow B. green C. orange D. blue
B
https://session.masteringbiology.com/problemAsset/2282322/1/MB_1321574_001.jpg Which wavelength of light is best absorbed by chlorophyll b? A. 400 nm B. 455 nm C. 540 nm D. 645 nm E. One cannot tell from this graph.
B
Which of the following statements best describes the relationship between the light-dependent and light-independent reactions of photosynthesis? A. The light-dependent reactions produce carbon dioxide, which is then used by the light-independent reactions. B. The light-independent reactions release energy, and the light-dependent reactions require energy. C. The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions. D. The light-dependent reactions pass electrons through an electron transport chain to the light-independent reactions.
C (Light energy drives the formation of ATP and NADPH during the light-dependent reactions; these energy molecules are then used during the light-independent reactions to form sugars.)
For which of the following reasons should glucose NOT be considered a primary product of photosynthesis? A. The carbon fixation reactions fix one CO2 at a time, not six. B. The first reduced sugar formed is 3-phosphoglyceraldehyde (3 carbons). C. Starch is the storage form of fixed carbon. D. All of the answers are correct.
D
Recently, Livingston et al. ( The Plant Cell 22: 221, 2010) isolated an Arabidopsis thaliana mutant with unusually high cyclic electron flow (hcef). See if you can predict the results they observed when comparing the hcef mutant plants with normal Arabidopsis plants. The researchers observed a large increase in the level of fructose-1,6-bisphosphate in the stroma of the hcef mutant. What enzyme do you predict is defective? A. fructose−1,6−bisphosphate reductase B. aldolase C. sucrose phosphatase D. fructose−1,6−bisphosphatase
D
Rubisco activase stimulates carbon fixation by rubisco by __________. Rubisco activase activity will be highest when the ADP/ATP ratio is __________. A. blocking photorespiration; high B. allowing rubisco to fix carbon in the dark; high C. producing ATP; low D. removing inhibitors from the rubisco active site; low
D
Which of the following enzymes represents the link between the light and dark reactions of photosynthesis? A. photosystem I B. photosystem II C. rubisco D. ferredoxin-NADP+ reductase
D
You obtain the pigments called carotenoids in your diet when you eat carrots. Why do carotenoids appear yellow and orange? A. They absorb yellow and orange wavelengths best. B. One cannot tell from this graph. C. Their line on this absorption spectrum is colored orange. D. They absorb blue/green light and reflect yellow and red wavelengths of light.
D
10) NADP+ is the coenzyme of choice in _______ while NAD+ is the coenzyme of choice in _________ reactions. A) anabolic; catabolic B) catabolic; anabolic C) metabolic; anabolic D) anabolic; both catabolic and anabolic E) both catabolic and anabolic; catabolic
a
24) Biosynthesis of sucrose occurs in the A) cytoplasm. B) stroma. C) thylakoid lumen. D) intermembrane space. E) stroma thylakoids.
a
31) Which of the following products CANNOT be used in the Calvin cycle? A) phosphoglycolate B) NADPH C) 3-phosphoglycerate D) CO2 E) ribulose-1, 5-bisphosphate
a
5) Of the following plastids, which is NOT paired with the proper contents? A) amyloplasts - amylase B) chromoplasts - non-chlorophyll pigments C) chloroplasts - chlorophyll D) proteinoplasts - protein E) elaioplasts - lipids
a
2) Carbon dioxide generally enters the plant through pores called A) mesophyll. B) stomata. C) the cuticle. D) connexons. E) bacteriochlorophylls.
b
20) In the Calvin Cycle, the enzyme that catalyzes the capture of carbon dioxide and the formation of 3- phosphoglycerate is A) phosphoglycerokinase. B) ribulose bisphosphate carboxylase/oxygenase (rubisco). C) triose phosphate isomerase. D) phosphoribulokinase. E) glyceraldehyde-3-phosphate dehydrogenase.
b
22) Which two triose phosphates are produced during the Calvin cycle and are the starting points for starch and sucrose synthesis? A) 3-phosphoglycerate and glyceraldehyde-3-phosphate B) dihydroxyacetone phosphate and glyceraldehyde-3-phosphate C) ribulose-1,5-bisphosphate and glycerol phosphate D) dihydroxyacetone phosphate and glycerate-1,3-bisphosphate E) 3-phosphoglycerate and ribulose-1,5-bisphosphate
b
32) Which of the following statements regarding CAM plants is true? A) Stomata are open during the day. B) Malate is stored in large vacuoles. C) CO2 is transported directly into mesophyll cells. D) Assimilate 25% less CO2 than C3 plants. E) Both B and C
b
7) Which of the following initially traps solar energy in the process of photosynthesis? A) water B) chlorophyll C) triose phosphate D) NADP+ E) ATP
b
1)Photoheterotrophs are best described as organisms that obtain energy to make ATP A) from organic compounds, but use sunlight to produce carbon sources. B) and organic compounds from sunlight. C) from sunlight but cannot make organic compounds from CO2. D) from some forms of chemicals. E) from organic compounds
c
11) Which of the following statements correctly characterizes the relationship between NADP+/NADPH and NAD+/NADH? A) Both are used extensively during photosynthesis in oxygenic phototrophs. B) Neither are helpful to oxygenic phototrophs. C) NADP+/NADPH has an extra phosphate compared to NAD +/NADH. D) NADP+/NADPH is used primarily for catabolic reactions E) Only NAD+/NADH is used to transport electrons and protons
c
13) The relationship between photosystem I (PSI) and photosystem II (P8II) is correctly described by which of the following statements? A) PSI absorbs only short wavelengths of light. B) Electrons are excited by PSI or PSII, but not both. C) PSI is designated P700, whereas P5II is designated P680. D) The absorption maximum of PSII is 700 nm. E) The absorption maximum of PSI is 680 nm
c
15) The ATP synthase complex in the thylakoid membrane A) contains an embedded CF 1 component and a protruding CF0 component. B) is identical to the F0F1 complex of mitochondria. C) performs photophosphorylation in oxygenic phototrophs. D) contains an assembly of hydrophobic polypeptides that function in ATP synthesis. E) all of the above
c
16) Which of the following is NOT an essential feature of electron transfer from water to NADP+? A) photosystem II complex B) photosystem I complex C) coenzyme Q D) plastocyanin (PC) E) cytochrome b6/f complex
c
21) The regeneration of what CO2 acceptor molecule allows for continous carbon assimilation in the Calvin cycle? A) glyceraldehyde-3-phosphate B) dihydroxyacetone phosphate C) ribulose-1, 5-bisphosphate D) glycerate-1, 3-bisphosphate E) 3-phosphoglycerate
c
25) Bacteria do not have organelles. How are they able to carry out photosynthesis? A) They are parasites of plants that do have organelles. B) They interact in a symbiotic relationship with eukaryotic plants. C) They use their cell membrane to carry out photosynthesis. D) DNA in the nucleoid captures solar energy E) 70S ribosomes function as photosystems.
c
27) Which of the following compounds is NOT a source of electrons for anoxygenic photosynthesis? A) SH- B) S2O32- C) H2O D) succinate E) All of the above are used.
c
3) The endosymbiotic theory states that mitochondria originated from A) a routine step in evolution. B) the fusion of several prokaryotes. C) purple bacteria entering and remaining in the cytoplasm of another cell. D) the slow evolution of various organelles over millions of years, particularly during the time of the dinosaurs. E) a long, intense period of lightning
c
14) Plastocyanin (PC) A) is a mobile electron carrier. B) is also called plastoquinol. C) carries only a single electron at a time. D) both A and C E) choices A, B, and C
d
17) The transfer of energy from a photoexcited electron to another electron of an adjacent pigment molecule is known as A) photoexcitation. B) quantum leap. C) photophosphorylation. D) resonance energy transfer. E) photorespiration.
d
18) A house plant seems to be growing slowly and lacks its normal bright green color. You call a botanist for advice. She suggests that the plant may be deficient in magnesium (Mg++). Why are these symptoms associated with Mg++ deficiency? A) Mg++ is important in the structure of many amino acids. B) Lack of Mg++ in the soil allows pathogenic bacteria to grow. C) Mg++ is required before NADPH can function. D) Mg++ is an important component in chlorophyll. E) Cytochromes require Mg++ to function properly.
d
23) Which three organelles are involved in the glycolate pathway? A) lysosome, chloroplast, rough endoplasmic reticulum B) mitochondrion, nucleus, lysosome C) peroxisome, smooth endoplasmic reticulum, chloroplast D) peroxisome, chloroplast, mitochondrion E) Golgi complex, peroxisome, lysosome
d
26) Bacteriochlorophyll differs from Chlorophyll a and b in structure and function. Which of the following statements correctly contrasts these types of chlorophyll? A) Bacteriochlorophyll has a porphyrin ring, whereas Chlorophyll does not. B) Chlorophyll has a phytol side chain, but bacteriochlorophyll does not. C) Chlorophyll has a methyl group attached to the porphyrin ring, whereas bacteriochlorophyll has a formyl group. D) Bacteriochlorophyll has a saturated carbon-carbon bond at one location in the porphyrin ring, whereas chlorophyll does not. E) Both A and D correctly contrast these types of chlorophyll.
d
28) Based upon the comparisons of anoxygenic and oxygenic photosythesis, the entry of oxygen into the atmosphere is most directly attributed to A) photosystem I. B) the Calvin cycle. C) photoreactivation. D) photosystem II. E) bacteriorhodopsin.
d
6) Which of the following is NOT an accessory pigment used to absorb photons that cannot be captured by chlorophyll? A) beta-carotene B) a phycobilin C) lutein D) phycochlorophyll E) phycocyanin
d
8) Which of the following pigments is found exclusively in red algae? A) chlorophyll a B) chlorophyll c C) lutein D) phycoerythrin E) B-carotene
d
9) NADPH contains the pentose sugar ______ and the nitrogenous base ______. A) glucose; thymine B) deoxyribose; cytosine C) deoxyribose; nicotinamide D) ribose; adenine E) ribose; nicotinamide
d
12) The Emerson enhancement effect A) was proposed by Robert Emerson in the 1980s. B) states that there are three or four separate photoreactions. C) is a synergistic phenomenon. D) is the result of two distinct photosystems. E) both C and D
e
19) Which of the following statements accurately describes the Calvin cycle? A) It is a carbon assimilation process. B) In this process, carbon dioxide is reduced to organic sugars. C) It occurs in the chloroplast stroma. D) The Calvin cycle is a means of carbon fixation. E) all of the above
e
29) The Hatch-Slack cycle occurs in which of the following types of plants? A) algae B) C3 plants C) C4 plants D) tropical grasses E) both C and D
e
30) The plants referred to as C3 and C4 plants get this designation based on the number of carbons in the first detectable product of carbon dioxide fixation. The C3 product is ______, whereas the C4 product is _______. A) glycerol; malate B) triose phosphate; oxaloacetate C) 3-phosphoglycerate; malate D) ribose; phosphoenolpyruvate E) 3-phosphoglycerate; oxaloacetate
e
4) In a chloroplast, the stroma is the A) cytochromes associated with the thylakoids. B) stack of thylakoids. C) region between in the inner and outer membranes. D) connection between the grana. E) central semi-fluid region.
e
