AP Biology Unit: Cellular Energetics (Chapters8, 9 and 10)
Chapter 9: Cellular Respiration Practice Test
1. Organisms that can manufacture their own chemical energy sources are called ______.
______
2. ______depend on energy stored in chemical bonds by autotrophs for their food energy.
______
3. Simple molecules are further broken down in cells in a process called ______, during which energy stored in their chemical bonds is used to power the production of ATP.
______
4. In glycolysis, a major portion of the energy remains in the final product, which is called ______.
______
5. For further derivation of energy, aerobic cells must convert pyruvate into acetyl-CoA by stripping off a C02 molecule. This process is known as ______.
______
6. Because the chemical formation of ATP is driven by a diffusion force similar to osmosis, this process is referred to as ______.
______
7. The amino acids must be first ______before they can be used in catabolic reactions.
______
8. Fats undergo a process called ______oxidation, in which the products are acetyl coenzyme molecules.
______
9. The first stage of cellular respiration,______, occurs with or without oxygen present.
______
10. An electron carrier that is used in harvesting energy from glucose molecules in a series of gradual steps in the cytoplasm is
A. pyruvate.
B. cyclic AMP.
C. ATP.
D. NAD+.
E. NADH.
11. In eukaryotes, the glycolytic reactions take place in the A. mitochondria of the cell.
B. cytoplasm of the cell.
C. ribosomes of the cell.
D. endoplasmic reticulum of each cell.
E. Golgi bodies of the cell.
12. The first stage of cellular respiration, and the oldest in terms of evolution is
A. decarboxylation.
B. deamination.
C. fermentation.
D. chemiosmosis.
E. glycolysis.
13. In the absence of oxygen, hydrogen atoms generated by glycolysis are donated to organic molecules in a process called
A. fermentation.
B. decarboxylation.
C. chemiosmosis.
D. electron transport chain reactions.
E. acetyl-CoA formation.
14. Which of the following statements about fermentation is false?
A. Fermentation takes place only in the absence of oxygen. B. The recipient of hydrogen atoms is an organic molecule.
C. Water is not one of the by-products.
D. The Krebs cycle and electron transfer system do not occur.
E. Cells can only undergo one type of fermentation.
15. Chemiosmotic generation of ATP is driven by
A. Pi transfer through the plasma membrane.
B. the Na+/K+ pump.
C. a difference in H+ concentration on the two sides of the mitochondrial membrane.
D. osmosis of macromolecules.
E. large quantities of ADP.
16. The reaction, C6H6O6 + 6O2 = 6 CO2 + 6 H2O, when it occurs in living cells is known as
A. aerobic fermentation.
B. anaerobic fermentation.
C. aerobic respiration.
D. glycolysis.
E. oxidative phosphorylation.
17. Out of the total amount of free energy potentially available from total oxidation of glucose, the number of ATP made by cells is equal to an energy efficiency of about
A. 2%. B. 25%.
C. 32%.
D. 75%.
E. 90%.
18. In oxidative respiration, energy is harvested from glucose molecules in a sequence of four major pathways. Which of the following is not one of these four pathways?
A. Krebs cycle
B. glycolysis
C. electron transfer through the transport chain
D. beta oxidation
E. pyruvate oxidation
19. In which of the following steps of glycolysis are two ATP molecules are required?
A. cleavage and rearrangement
B. glucose priming
C. oxidation
D. pyruvate formation
E. acetyl-CoA formation
20. All of the following are the end products of glycolysis except
A. pyruvate.
B. ATP. C. NADH.
D. NAD+.
E. energy.
21. The enzymes catalyzing the reactions of glycolysis are found in the
A. mitochondria.
B. cytoplasm.
C. chloroplasts.
D. nucleus.
E. Golgi apparatus.
22. The decarboxylation step of oxidation of pyruvate takes place in the
A. cytoplasm.
B. Golgi body.
C. ribosome.
D. mitochondrion.
E. nucleus.
23. In the cyclic reaction sequence called the Krebs cycle, the following chemical events take place except
A. the acetyl group is joined with a four carbon molecule, oxaloacetate.
B. the resulting six carbon molecule is oxidized.
C. electrons generated are used to produce NADH. D. two carbons per cycle are made into CO2 molecules.
E. pyruvate molecules are restored to the cycle.
24. A single glucose molecule can drive the Krebs cycle
A. one turn.
B. two turns.
C. three turns.
D. four turns.
E. six turns.
25. The oxygen utilized in cellular respiration finally shows up as
A. CO2.
B. ATP.
C. new O2.
D. H2O.
E. part of a sugar.
26. The enzymes of the Krebs cycle are located in the
A. cytoplasm.
B. inter-membrane space of mitochondria.
C. vesicles of the ER.
D. outer membrane of the mitochondria. E. matrix of the mitochondria.
27. The electron transport chain consists of all of the following except
A. NADH dehydrogenase.
B. cytochrome complex.
C. oxygenase.
D. cytochrome c oxidase.
E. ubiquinone, Q.
28. The energy released in the mitochondrial electron transport chain is used to transport protons into the
A. matrix.
B. cytoplasm.
C. ER.
D. inter-membrane space of mitochondria.
E. enzyme complex of the Krebs cycle.
29. Regardless of the electron or hydrogen acceptor used, one of the products of fermentation is always
A. ADP.
B. ATP.
C. NAD+.
D. pyruvate. E. alcohol.
30. A gram of fatty acid can yield how many more times the energy as one gram of glucose?
A. 6
B. 5
C. 4
D. 3
E. 2
31. A biochemist wants to control the initial substrate-level phosphorylation that occurs in the tracheal cells of grasshoppers once glucose has crossed the plasma membrane. This means that he will
A. have to prevent cAMP from entering the tracheal cells.
B. have to prevent pyruvate reduction from occurring.
C. have to prevent glycolysis from occurring in the mitochondria.
D. have to prevent glycolysis from occurring in the cytoplasm.
E. have to prevent aerobic respiration in the cytoplasm.
32. Select the correct sequence concerning glucose catabolism.
A. glycolysis Pyruvate Acetyl CoA Electron Transport Chain Krebs Cycle
B. glycolysis Pyruvate Acetyl CoA Krebs Cycle Electron Transport Chain
C. glycolysis Acetyl CoA Pyruvate Electron Transport Chain Krebs Cycle
D. glycolysis Acetyl CoA Pyruvate Krebs Cycle Electron Transport Chain
33. When substrate-level phosphorylation occurs, it means that
A. NAD is converted into NADH.
B. ATP is converted into ADP + a phosphate group.
C. ADP is converted into ATP by addition of a phosphate group.
D. cAMP is converted into ADP by adding a phosphate group.
E. NADH is converted into NAD + H.
34. When ATP levels are high, oxidative pathways are inhibited, so acetyl-CoA is channeled into
A. fatty acid synthesis.
B. pyruvate formation.
C. the Krebs cycle.
D. the electron transport system.
E. NAD production.
35. The Krebs cycle occurs in the mitochondria. There are nine biochemical reactions involved in the Krebs cycle, and they are highly ordered. Select the correct order from the following choices. (Note: These are abbreviated and do not show NAD, ADP, ATP, or FAD.)
A. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate forming citrate which forms beta-ketoglutarate which forms succinylCoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate
B. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate forming citrate which forms alpha-ketoglutarate which forms succinylCoA which forms succinate which forms malate which forms fumarate which forms oxaloacetate C. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate which forms alpha- ketoglutarate forming citrate which forms succinylCoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate
D. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate forming citrate which forms alpha-ketoglutarate which forms succinylCoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate
36. As a forensic pathologist, you have just completed an autopsy of a poisoning victim. After a thorough examination, you conclude that the victim died of cyanide poisoning. You know that cyanide binds to the cytochrome oxidase complex, and therefore list the official cause of death as suffocation due to cyanide exposure. However, a more technical explanation would be that all of the following aspects of cellular respiration were inhibited except
A. the reduction of NAD+ and FAD.
B. electron transport.
C. oxidative phosphorylation.
D. proton pumping.
37. You are examining some live cells in a Petri dish, when you begin to imagine what you would do if suddenly one of them were to burst into flames. Of course, in order for this to happen the cell would have to
A. transfer electrons to intermediate electron carriers before transferring them to oxygen.
B. transfer electrons directly to oxygen, skipping the intermediate electron carriers.
C. transfer electrons directly to carbon dioxide, skipping the intermediate electron carriers.
D. transfer electrons to intermediate electron carriers before transferring them to carbon dioxide.
38. Which of the following molecules does not cross the inner membrane of the mitochondria?
A. ATP
B. acetyl-CoA
C. pyruvate
D. oxygen
39. The chemical 2,4 dinitrophenol (DNP) is used in the manufacturing of dyes, wood preservatives, explosives, and insect control substances, and as a photographic developer. Products containing DNP are toxic because DNP uncouples oxidative phosphorylation. In a cell exposed to DNP, how many ATP molecules would be generated per molecule of glucose?
A. 2
B. 4
C. 36
D. 38
40. Your friend is having difficulty keeping track of the energy flow from glucose through glycolysis, the Krebs cycle and electron transport. Your best advice would be to
A. follow ATP production.
B. follow the protons.
C. follow NAD+ production.
D. follow the electrons.
41. If ATP synthase had a mutation in the F1 complex portion of the protein, which of the following functions is most likely to be affected? A. rotation of the rotor
B. flow of protons through the channel
C. conversion of ADP and Pi to ATP
D. insertion of the enzyme into the membrane
42. High levels of citrate in the cell would result in which of the following?
A. inhibition of phosphofructokinase and the slow down of glycolysis
B. inhibition of citrate synthase and the slow down of glycolysis
C. inhibition of phosphofructokinase and the slow down of the Krebs cycle
D. inhibition of citrate synthase and the slow down of the Krebs cycle
43. You arrive at your second home in the mountains looking forward to a relaxing vacation. Unfortunately, when you turn on the water you smell hydrogen sulfide (H2S) gas. After some research, you find out that the H2S may be due to the presence of sulfur bacteria living in your pipes. Which of the following molecules would these bacteria use as an electron acceptor?
A. O2
B. H20
C. SO4
D. H2S
44. In order to lose weight and reduce body fat, a friend of yours decided to eliminate all fat from their diet, while consuming unrestricted amounts of carbohydrates. Aside from being an unhealthy way to try to lose weight, why would this approach be unsuccessful at reducing body fat?
A. Excess acetyl-CoA from glycolysis will be channeled into production of body fat. B. Excess acetyl-CoA from the Krebs cycle will be channeled into production of body fat.
C. Excess acetyl-CoA will undergo beta-oxidation to produce body fat.
D. Excess acetyl-CoA will undergo deamination to produce body fat.
45. Some prokaryotic organisms use nitrogen fixation to obtain organic nitrogen. Which of the following statements about nitrogen fixation is false?
A. Nitrogen fixation requires the breaking a NN triple bond.
B. Nitrogen fixation evolved after anaerobic photosynthesis, but before aerobic respiration.
C. Nitrogen fixation can only occur in the presence of oxygen.
D. Nitrogen fixation evolved as a way to obtain organic nitrogen for production of proteins and nucleic acids.
Cellular Respiration Practice Test Key
1. Organisms that can manufacture their own chemical energy sources are called ______. autotrophs
Difficulty: Easy Raven - 007 Chapter... #1
2. ______depend on energy stored in chemical bonds by autotrophs for their food energy. Heterotrophs
Difficulty: Easy Raven - 007 Chapter... #2
3. Simple molecules are further broken down in cells in a process called ______, during which energy stored in their chemical bonds is used to power the production of ATP. respiration
Difficulty: Easy Raven - 007 Chapter... #3
4. In glycolysis, a major portion of the energy remains in the final product, which is called ______. pyruvate
Difficulty: Easy Raven - 007 Chapter... #5
5. For further derivation of energy, aerobic cells must convert pyruvate into acetyl-CoA by stripping off a C02 molecule. This process is known as ______. decarboxylation
Difficulty: Easy Raven - 007 Chapter... #6
6. Because the chemical formation of ATP is driven by a diffusion force similar to osmosis, this process is referred to as ______. chemiosmosis
Difficulty: Easy Raven - 007 Chapter... #8
7. The amino acids must be first ______before they can be used in catabolic reactions. deaminated
Difficulty: Easy Raven - 007 Chapter... #10
8. Fats undergo a process called ______oxidation, in which the products are acetyl coenzyme molecules. beta
Difficulty: Easy Raven - 007 Chapter... #11
9. The first stage of cellular respiration,______, occurs with or without oxygen present. glycolysis
Difficulty: Easy Raven - 007 Chapter... #12
10. An electron carrier that is used in harvesting energy from glucose molecules in a series of gradual steps in the cytoplasm is a. pyruvate. b. cyclic AMP. c. ATP.
D. NAD+. e. NADH.
Difficulty: Easy Raven - 007 Chapter... #15
11. In eukaryotes, the glycolytic reactions take place in the a. mitochondria of the cell.
B. cytoplasm of the cell. c. ribosomes of the cell. d. endoplasmic reticulum of each cell. e. Golgi bodies of the cell.
Difficulty: Easy Raven - 007 Chapter... #16
12. The first stage of cellular respiration, and the oldest in terms of evolution is a. decarboxylation. b. deamination. c. fermentation. d. chemiosmosis.
E. glycolysis.
Difficulty: Easy Raven - 007 Chapter... #17
13. In the absence of oxygen, hydrogen atoms generated by glycolysis are donated to organic molecules in a process called
A. fermentation. b. decarboxylation. c. chemiosmosis. d. electron transport chain reactions. e. acetyl-CoA formation.
Difficulty: Moderate Raven - 007 Chapter... #18
14. Which of the following statements about fermentation is false? a. Fermentation takes place only in the absence of oxygen. b. The recipient of hydrogen atoms is an organic molecule. c. Water is not one of the by-products. d. The Krebs cycle and electron transfer system do not occur.
E. Cells can only undergo one type of fermentation.
Difficulty: Difficult Raven - 007 Chapter... #20
15. Chemiosmotic generation of ATP is driven by
a. Pi transfer through the plasma membrane. b. the Na+/K+ pump.
C. a difference in H+ concentration on the two sides of the mitochondrial membrane. d. osmosis of macromolecules. e. large quantities of ADP.
Difficulty: Moderate Raven - 007 Chapter... #21
16. The reaction, C6H6O6 + 6O2 = 6 CO2 + 6 H2O, when it occurs in living cells is known as a. aerobic fermentation. b. anaerobic fermentation.
C. aerobic respiration. d. glycolysis. e. oxidative phosphorylation.
Difficulty: Difficult Raven - 007 Chapter... #22
17. Out of the total amount of free energy potentially available from total oxidation of glucose, the number of ATP made by cells is equal to an energy efficiency of about a. 2%. b. 25%.
C. 32%. d. 75%. e. 90%.
Difficulty: Difficult Raven - 007 Chapter... #23
18. In oxidative respiration, energy is harvested from glucose molecules in a sequence of four major pathways. Which of the following is not one of these four pathways? a. Krebs cycle b. glycolysis c. electron transfer through the transport chain
D. beta oxidation e. pyruvate oxidation
Difficulty: Moderate Raven - 007 Chapter... #24
19. In which of the following steps of glycolysis are two ATP molecules are required? a. cleavage and rearrangement
B. glucose priming c. oxidation d. pyruvate formation e. acetyl-CoA formation
Difficulty: Difficult Raven - 007 Chapter... #25
20. All of the following are the end products of glycolysis except a. pyruvate. b. ATP. c. NADH.
D. NAD+. e. energy.
Difficulty: Moderate Raven - 007 Chapter... #27
21. The enzymes catalyzing the reactions of glycolysis are found in the a. mitochondria.
B. cytoplasm. c. chloroplasts. d. nucleus. e. Golgi apparatus.
Difficulty: Moderate Raven - 007 Chapter... #29
22. The decarboxylation step of oxidation of pyruvate takes place in the a. cytoplasm. b. Golgi body. c. ribosome.
D. mitochondrion. e. nucleus.
Difficulty: Moderate Raven - 007 Chapter... #30
23. In the cyclic reaction sequence called the Krebs cycle, the following chemical events take place except a. the acetyl group is joined with a four carbon molecule, oxaloacetate. b. the resulting six carbon molecule is oxidized. c. electrons generated are used to produce NADH.
d. two carbons per cycle are made into CO2 molecules.
E. pyruvate molecules are restored to the cycle.
Difficulty: Difficult Raven - 007 Chapter... #32
24. A single glucose molecule can drive the Krebs cycle a. one turn.
B. two turns. c. three turns. d. four turns. e. six turns.
Difficulty: Moderate Raven - 007 Chapter... #33
25. The oxygen utilized in cellular respiration finally shows up as
a. CO2. b. ATP.
c. new O2.
D. H2O. e. part of a sugar.
Difficulty: Difficult Raven - 007 Chapter... #35
26. The enzymes of the Krebs cycle are located in the a. cytoplasm. b. inter-membrane space of mitochondria. c. vesicles of the ER. d. outer membrane of the mitochondria. E. matrix of the mitochondria.
Difficulty: Moderate Raven - 007 Chapter... #37
27. The electron transport chain consists of all of the following except a. NADH dehydrogenase. b. cytochrome complex.
C. oxygenase. d. cytochrome c oxidase. e. ubiquinone, Q.
Difficulty: Moderate Raven - 007 Chapter... #38
28. The energy released in the mitochondrial electron transport chain is used to transport protons into the a. matrix. b. cytoplasm. c. ER.
D. inter-membrane space of mitochondria. e. enzyme complex of the Krebs cycle.
Difficulty: Moderate Raven - 007 Chapter... #39
29. Regardless of the electron or hydrogen acceptor used, one of the products of fermentation is always a. ADP. b. ATP.
C. NAD+. d. pyruvate. e. alcohol.
Difficulty: Moderate Raven - 007 Chapter... #41
30. A gram of fatty acid can yield how many more times the energy as one gram of glucose? a. 6 b. 5 c. 4 d. 3
E. 2
Difficulty: Moderate Raven - 007 Chapter... #45
31. A biochemist wants to control the initial substrate-level phosphorylation that occurs in the tracheal cells of grasshoppers once glucose has crossed the plasma membrane. This means that he will a. have to prevent cAMP from entering the tracheal cells. b. have to prevent pyruvate reduction from occurring. c. have to prevent glycolysis from occurring in the mitochondria.
D. have to prevent glycolysis from occurring in the cytoplasm. e. have to prevent aerobic respiration in the cytoplasm.
Difficulty: Difficult Raven - 007 Chapter... #48
32. Select the correct sequence concerning glucose catabolism. a. glycolysis Pyruvate Acetyl CoA Electron Transport Chain Krebs Cycle
B. glycolysis Pyruvate Acetyl CoA Krebs Cycle Electron Transport Chain c. glycolysis Acetyl CoA Pyruvate Electron Transport Chain Krebs Cycle d. glycolysis Acetyl CoA Pyruvate Krebs Cycle Electron Transport Chain
Difficulty: Moderate Raven - 007 Chapter... #49
33. When substrate-level phosphorylation occurs, it means that a. NAD is converted into NADH. b. ATP is converted into ADP + a phosphate group.
C. ADP is converted into ATP by addition of a phosphate group. d. cAMP is converted into ADP by adding a phosphate group. e. NADH is converted into NAD + H.
Difficulty: Moderate Raven - 007 Chapter... #52
34. When ATP levels are high, oxidative pathways are inhibited, so acetyl-CoA is channeled into
A. fatty acid synthesis. b. pyruvate formation. c. the Krebs cycle. d. the electron transport system. e. NAD production.
Difficulty: Moderate Raven - 007 Chapter... #53
35. The Krebs cycle occurs in the mitochondria. There are nine biochemical reactions involved in the Krebs cycle, and they are highly ordered. Select the correct order from the following choices. (Note: These are abbreviated and do not show NAD, ADP, ATP, or FAD.) a. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate forming citrate which forms beta-ketoglutarate which forms succinylCoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate b. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate forming citrate which forms alpha-ketoglutarate which forms succinylCoA which forms succinate which forms malate which forms fumarate which forms oxaloacetate c. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate which forms alpha- ketoglutarate forming citrate which forms succinylCoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate
D. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate forming citrate which forms alpha-ketoglutarate which forms succinylCoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate
Difficulty: Difficult Raven - 007 Chapter... #54
36. As a forensic pathologist, you have just completed an autopsy of a poisoning victim. After a thorough examination, you conclude that the victim died of cyanide poisoning. You know that cyanide binds to the cytochrome oxidase complex, and therefore list the official cause of death as suffocation due to cyanide exposure. However, a more technical explanation would be that all of the following aspects of cellular respiration were inhibited except
A. the reduction of NAD+ and FAD. b. electron transport. c. oxidative phosphorylation. d. proton pumping.
Difficulty: Difficult Raven - 007 Chapter... #65
37. You are examining some live cells in a Petri dish, when you begin to imagine what you would do if suddenly one of them were to burst into flames. Of course, in order for this to happen the cell would have to a. transfer electrons to intermediate electron carriers before transferring them to oxygen.
B. transfer electrons directly to oxygen, skipping the intermediate electron carriers. c. transfer electrons directly to carbon dioxide, skipping the intermediate electron carriers. d. transfer electrons to intermediate electron carriers before transferring them to carbon dioxide.
Difficulty: Difficult Raven - 007 Chapter... #67
38. Which of the following molecules does not cross the inner membrane of the mitochondria? a. ATP
B. acetyl-CoA c. pyruvate d. oxygen
Difficulty: Difficult Raven - 007 Chapter... #68
39. The chemical 2,4 dinitrophenol (DNP) is used in the manufacturing of dyes, wood preservatives, explosives, and insect control substances, and as a photographic developer. Products containing DNP are toxic because DNP uncouples oxidative phosphorylation. In a cell exposed to DNP, how many ATP molecules would be generated per molecule of glucose? a. 2
B. 4 c. 36 d. 38
Difficulty: Difficult Raven - 007 Chapter... #69
40. Your friend is having difficulty keeping track of the energy flow from glucose through glycolysis, the Krebs cycle and electron transport. Your best advice would be to a. follow ATP production. b. follow the protons. c. follow NAD+ production.
D. follow the electrons.
Difficulty: Difficult Raven - 007 Chapter... #70
41. If ATP synthase had a mutation in the F1 complex portion of the protein, which of the following functions is most likely to be affected? a. rotation of the rotor b. flow of protons through the channel
C. conversion of ADP and Pi to ATP d. insertion of the enzyme into the membrane
Difficulty: Difficult Raven - 007 Chapter... #71
42. High levels of citrate in the cell would result in which of the following?
A. inhibition of phosphofructokinase and the slow down of glycolysis b. inhibition of citrate synthase and the slow down of glycolysis c. inhibition of phosphofructokinase and the slow down of the Krebs cycle d. inhibition of citrate synthase and the slow down of the Krebs cycle
Difficulty: Difficult Raven - 007 Chapter... #72
43. You arrive at your second home in the mountains looking forward to a relaxing vacation. Unfortunately, when you turn on the water you smell hydrogen sulfide (H2S) gas. After some research, you find out that the H2S may be due to the presence of sulfur bacteria living in your pipes. Which of the following molecules would these bacteria use as an electron acceptor?
a. O2
b. H20
C. SO4
d. H2S
Difficulty: Difficult Raven - 007 Chapter... #73
44. In order to lose weight and reduce body fat, a friend of yours decided to eliminate all fat from their diet, while consuming unrestricted amounts of carbohydrates. Aside from being an unhealthy way to try to lose weight, why would this approach be unsuccessful at reducing body fat? a. Excess acetyl-CoA from glycolysis will be channeled into production of body fat. B. Excess acetyl-CoA from the Krebs cycle will be channeled into production of body fat. c. Excess acetyl-CoA will undergo beta-oxidation to produce body fat. d. Excess acetyl-CoA will undergo deamination to produce body fat.
Difficulty: Difficult Raven - 007 Chapter... #74
45. Some prokaryotic organisms use nitrogen fixation to obtain organic nitrogen. Which of the following statements about nitrogen fixation is false? a. Nitrogen fixation requires the breaking a NN triple bond. b. Nitrogen fixation evolved after anaerobic photosynthesis, but before aerobic respiration.
C. Nitrogen fixation can only occur in the presence of oxygen. d. Nitrogen fixation evolved as a way to obtain organic nitrogen for production of proteins and nucleic acids.
Difficulty: Difficult Raven - 007 Chapter... #75
Cellular Respiration Practice Test Summary
Category # of Questions Difficulty: Difficult 18 Difficulty: Easy 12 Difficulty: Moderate 15 Raven - 007 Chapter... 45