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Photosynthesis and Respiration MCQ Questions & Answers

Photosynthesis and Respiration MCQs : This section focuses on the "Photosynthesis and Respiration". These Multiple Choice Questions (MCQs) should be practiced to improve the Photosynthesis and Respiration skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.

Question 1

Rubisco (RuBP Carboxylase-oxygenase enzyme), glyceraldehyde 3-phosphate, and NADPH all play a role in

A. the dark reactions of photosynthesis
B. the breakdown of glucose into CO2
C. cellular respiration when O2 is present
D. alcohol fermentation

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Question 2

More ATP is manufactured during __________ than at any other time in all of cellular metabolism.

A. fermentation
B. glycolysis
C. the light reactions of photosynthesis
D. oxidative phosphorylation

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Question 3

A eukaryotic cell that can carry out only fermentation instead of the complete aerobic respiration of glucose

A. produces less CO2
B. is lacking in O2
C. has mitochondria present
D. all of these

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Question 4

What is the maximum absorption wavelength for photosystem I in green plants?

A. 550 nm
B. 600 nm
C. 700 nm
D. 750 nm

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Question 5

What process in cellular respiration is essentially the reverse of carbon fixation in photosynthesis?

A. Glycolysis
B. Citric acid cycle
C. Oxidative phosphorylation
D. Alcohol fermentation

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Question 6

In cells having organelles, the steps of the Krebs cycle and the electron transport system occur in the

A. cell membrane
B. mitochondria
C. endoplasmic reticulum
D. none of these

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Question 7

Where does the O2 come from that is essential for the proper functioning of oxidative phosphorylation?

A. Fermentation
B. Light reactions of photosynthesis
C. Dark reactions of photosynthesis
D. Carbon fixation

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Question 8

Which of the following statements about energy metabolism is false?

A. The energy that powers living systems ultimately comes from the sun
B. All animals in some way rely on plants for their energy
C. Plants provide the water and CO2 that animals need to carry out respiration
D. All eukaryotic organisms carry out respiration in the presence of O2

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Question 9

Which one of the following is a product of both cyclic and noncyclic photophosphorylation?

B. O2
D. Carbohydrate

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Question 10

NADP+ is reduced to NADPH during

A. light dependent reactions
B. photorespiration
C. calvin cylcle
D. none of these

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Question 11

During the light-dependent reactions of photosynthesis, which of the following does not occur?

A. Splitting of water
B. Carbon dioxide fixation
C. Release of oxygen
D. Absorption of light energy by photosystems

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Question 12

The breakdown of glucose occurs by the process known as

A. glycolysis
B. fermentation
C. anaerobic respiration
D. Krebs cycle

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Question 13

In oxygenic photosynthesis, the electron donor is

A. water
B. oxygen

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Question 14

Carbon fixation requires the expenditure of ATP molecules which is generated by

A. formation of glucose during the Calvin cycle
B. replenishment of chlorophyll
C. ETS (electron transfer system) during the light reactions
D. none of the above

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Question 15

Electron transport systems play a vital role in

A. Calvin cycle
B. photorespiration
C. light-dependent reactions
D. all of these

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Question 16

In the initial step of photosynthesis, sunlight energizes the electron pair of

A. adenosine triphosphate (ATP)
B. chlorophyll pigments
C. water
D. carbon dioxide

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Question 17

Antenna complexes, electron transport chains, and carbon fixation are all found in

A. animal cells
B. bacterial cells
C. plant cells
D. association with the reactions of the citric acid cycle

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Question 18

Assume the combined processes of photosynthesis and cellular respiration, the electrons that start as part of H2O at the beginning of the light reactions end up attaching to

A. O2 to make new H2O
B. NADPH to make new glucose
C. pyruvate to make ethanol
D. electron transport carriers to make O2

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Question 19

In noncyclic photophosphorylation, the ultimate acceptor of electrons that have been produced from the splitting of water is

B. chlorophyll a
C. carbon dioxide
D. chlorophyll b

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Question 20

Oxidative phosphorylation is to respiration as __________ is to photosynthesis

A. carbon fixation
B. electron transport chain
C. light capture by chlorophyll
D. reduction of NADPH

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Question 21

The end products of noncyclic photophosphorylation are

A. O2, ATP and NADPH
B. carbon dioxide, PGAL (phosphoglyceraldehyde), and H2
C. water, ADP and NADP+
D. carbon dioxide, ATP and water

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Question 22

Which of the following serves as a reactant in photosynthesis and a product in cellular respiration?

A. O2
B. CO2
C. Sunlight

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Question 23

As a result of the photosynthetic process, which product is formed?

A. Oxygen
B. Water
C. Carbon dioxide
D. Both (a) and (b)

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Question 24

In the Calvin cycle, carbon dioxide is fixed in a reaction with the

A. ribulose diphosphate
B. ribulose phosphate
C. ribose tri phosphate
D. 3-phosphoglyceric acid

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Question 25

Which of the following is the reduced form of a temporary electron carrier molecule?

D. CO2

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Question 26

Which of the following structures or processes are logically associated with chloroplasts?

A. Plant cells
B. Chlorophyll
C. Thylakoid membranes
D. All of these

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Question 27

What do NAD+, NADP+, and FAD+ all have in common?

A. They are reduced
B. They have a full complement of electrons
C. They are oxidized
D. They are what is used during carbon fixation in photosynthesis

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Question 28

Carbon dioxide is reduced in

A. noncyclic photophosphorylation
B. the Calvin cycle
C. the light reactions
D. both light and dark reactions

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Question 29

Which enzyme is involved in carbon-fixation reaction?

A. NADP reductase
B. Cytochrome reductase
C. Ribulose bisphosphate carboxylase
D. Glycerol kinase

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Question 30

In algae, photosynthesis takes place in

A. choloroplasts
B. cell membrane
C. mitochondria
D. none of the above

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Question 31

A cyclic electron transport process is the characteristic of

A. photosynthesis
B. methane oxidation
C. sulfide oxidation
D. methane production

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Question 32

What do coenzyme A, CO2, oxaloacetate, and FADH2 all have in common?

A. They are all components or products of the citric acid cycle
B. They are part of the dark reactions of photosynthesis
C. They are part of the reactions of lactic acid fermentation
D. They are all elements of oxidative phosphorylation

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Question 33

Where do the protons come from that make up the proton gradient used in the light reactions of photosynthesis?

A. Glucose
C. H2O

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Question 34

The followings are the products of the light reactions of photosynthesis except

B. oxygen
D. glucose

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Question 35

The cytochrome c oxidase complex

A. accepts electrons from cyt c
B. donates four electrons to O2
C. pumps protons out of the matrix space
D. all of these

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Question 36

The electrons that are released by the splitting of water during photosynthesis ultimately end up in

B. O2
D. rubisco

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Question 37

Hydrogen (electron) acceptor in the light reactions is


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Question 38

In oxygenic photosynthesis, water is split in order to provide the

A. electrons needed to reduce P680
B. O2 needed for the dark reactions
C. electrons needed to reduce NADH
D. electrons needed for cyclic photophosphorylation

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Question 39

The manufacture of ATP in both photosynthesis and respiration is made possible by

A. the existence of a proton gradient across specific membranes
B. the action of ATP synthase
C. energy from the movement of electrons
D. All of the above

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Question 40

The vast majority of the molecules that act as energy carriers to power cellular activities are made in

A. the nucleus
B. the Golgi apparatus
C. the cytosol
D. the mitochondria and chloroplasts

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Question 41

The rate of photorespiration in most plants increases at.higher temperatures. Some plants have evolved a somewhat round-about system to deal with this problem. This series of reactions is called

A. ETS (electron transfer system in light reactions
B. C4 pathway
C. Photosystem II
D. Calvin cycle

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Question 42

If the oxygen is labeled in CO2 and provide this CO2 to a plant, where it is expected to find this labeled oxygen after the plant had undergone photosynthesis?

A. In the water used
B. In the NADPH
C. In the carbohydrate produced
D. In the oxygen given off by the plant

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