Photosynthesis and Respiration Multiple Choice Questions with Answers

61 In a plant cell, where are the ATP synthase complexes located?

A thylakoid membrane

B plasma membrane

C inner mitochondrial membrane

D A and C

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Answer: A and C

62 Which of the following statements best describes the relationship between photosynthesis and respiration?

A Respiration is the reversal of the biochemical pathways of photosynthesis

B Photosynthesis stores energy in complex organic molecules, while 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

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Answer: Photosynthesis stores energy in complex organic molecules, while respiration releases it

63 Where are the molecules of the electron transport chain found in plant cells?

A thylakoid membranes of chloroplasts

B stroma of chloroplasts

C inner membrane of mitochondria

D matrix of mitochondria

View Answer

Answer: thylakoid membranes of chloroplasts

64 Synthesis of ATP by the chemiosmotic mechanism occurs during

A Photosynthesis

B Respiration

C Both Photosynthesis And Respiration

D Neither Photosynthesis Nor Respiration

View Answer

Answer: Both Photosynthesis And Respiration

65 Produces NADPH

A 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

View Answer

Answer: light reactions alone

66 Requires CO2

A 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

View Answer

Answer: the Calvin cycle alone

67 The sugar that results from three ʺturnsʺ of the Calvin cycle is glyceraldehyde -3-phosphate (G3P). Which of the following is a consequence of this?

A Formation of a molecule of glucose would require 9 ʺturns.ʺ

B G3P more readily forms sucrose and other disaccharides than it does monosaccharides

C Some plants would not taste sweet to us

D The formation of starch in plants involves assembling many G3P molecules, with or without further rearrangements

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Answer: The formation of starch in plants involves assembling many G3P molecules, with or without further rearrangements

68 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 within the thylakoid is less than that of the stroma

B The pH of the stroma is higher than that of the other two measurements

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

View Answer

Answer: The pH within the thylakoid is less than that of the stroma

69 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

View Answer

Answer: fix CO2 into organic acids during the night

70 In autotrophic bacteria, where are the enzymes located that can carry on organic synthesis?

A chloroplast membranes

B nuclear membranes

C free in the cytosol

D along the inner surface of the plasma membrane

View Answer

Answer: along the inner surface of the plasma membrane

71 Photorespiration lowers the efficiency of photosynthesis by preventing the formation of

A carbon dioxide molecules

B 3-phosphoglycerate molecules

C ATP molecules

D RuBP carboxylase molecules

View Answer

Answer: 3-phosphoglycerate molecules

72 The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why?

A Each one minimizes both water loss and rate of photosynthesis

B C4 compromises on water loss and CAM compromises on photorespiration

C Each one both minimizes photorespiration and optimizes the Calvin cycle

D CAM plants allow more water loss, while C4 plants allow less CO 2 into the plant

View Answer

Answer: Each one both minimizes photorespiration and optimizes the Calvin cycle

73 The light reactions of photosynthesis supply the Calvin cycle with

A light energy

B CO2 and ATP

C H2O and NADPH

D ATP and NADPH

View Answer

Answer: ATP and NADPH

74 Which process is most directly driven by light energy?

A creation of a pH gradient by pumping protons across the thylakoid membrane

B carbon fixation in the stroma

C reduction of NADP+ molecules

D removal of electrons from chlorophyll molecules

View Answer

Answer: removal of electrons from chlorophyll molecules

75 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 absorption of light energy by chlorophyll

C the flow of electrons from photosystem II to photosystem I

D the synthesis of ATP

View Answer

Answer: the synthesis of ATP

76 Reduction of oxygen which forms water occurs during

A photosynthesis

B respiration

C both photosynthesis and respiration

D photorespiration

View Answer

Answer: respiration

77 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

B They dissipate excessive light energy

C They cover the sensitive chromosomes of the plant

D They reflect orange light

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