Question 1

Why are the reaction centers of photosystems composed of several structurally different pigments?

Accepted Answer

A)   Excited electrons must pass through several pigments before they can be transferred to electron acceptors of the electron transport chain.
B)   This arrangement enables the plant to absorb light energy of a variety of wavelengths.
C)   This arrangement enables the plant to absorb more photons from light energy, all of which are at the same wavelength.
D)   This arrangement enables the reaction center to excite electrons to a higher energy level.

Question 2

In mitochondria, an electron transport chain pumps protons from the matrix into the intermembrane space, whereas in chloroplasts, an electron transport chain pumps protons from the ________.

Accepted Answer

A)   matrix to the stroma
B)   stroma to the thylakoid space
C)   thylakoid space to the matrix
D)   thylakoid space to the stroma

Question 3

Compared to C₃ plants, C₄ plants ________.

Accepted Answer

A)   can continue to fix CO₂ even at lower CO₂ concentrations and higher oxygen concentrations
B)   have higher rates of photorespiration
C)   do not use rubisco for carbon fixation
D)   make a four-carbon compound, oxaloacetate, which is then delivered to the citric acid cycle in mitochondria

Question 4

In mechanism, photophosphorylation is most similar to

Accepted Answer

A)   substrate-level phosphorylation in glycolysis.
B)   oxidative phosphorylation in cellular respiration.
C)   carbon fixation.
D)   reduction of NADP⁺.

Question 5

Which of the following events accompanies absorption of energy by chlorophyll molecules of the reaction-center complex?

Accepted Answer

A)   ATP is synthesized from the energy absorbed.
B)   An electron is excited.
C)   NADP⁺ is reduced to NADPH.
D)   A molecule of water is split.

Question 6

P680⁺ is said to be the strongest biological oxidizing agent. Given its function, why is this necessary?

Accepted Answer

A)   It is the receptor for the most excited electron in either photosystem of photosynthesis.
B)   It is the molecule that transfers electrons to plastoquinone (Pq)  of the electron transfer system.
C)   It transfers its electrons to reduce NADP⁺ to NADPH.
D)   It obtains electrons from the oxygen atom in a water molecule, so it must have a stronger attraction for electrons than oxygen has.

Question 7

Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light. What did Engelmann conclude about the congregation of bacteria in the red and blue areas?

Accepted Answer

A)   Bacteria congregated in these areas due to an increase in the temperature of the red and blue light.
B)   Bacteria congregated in these areas because these areas had the most oxygen being released.
C)   Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths.
D)   Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis.

Question 8

The mechanism of photophosphorylation is most similar to which of the following processes?

Accepted Answer

A)   substrate-level phosphorylation in glycolysis
B)   oxidative phosphorylation in cellular respiration
C)   the Calvin cycle
D)   reduction of NADP⁺

Question 9

What happens to the free energy released as electrons are passed from photosystem II to photosystem I through a series of electron carriers?

Accepted Answer

A)   It excites electrons of the reaction center in photosystem I.
B)   It is used to establish and maintain a proton gradient.
C)   It is used to synthesize ATP through substrate-level phosphorylation.
D)   It is used to phosphorylate NAD⁺ to NADPH.

Question 10

Under what conditions do photosynthesis and cellular respiration occur in plants?

Accepted Answer

A)   Photosynthesis and cellular respiration occur only in the light.
B)   Photosynthesis occurs only in the light, and cellular respiration occurs only in the dark.
C)   Photosynthesis occurs only in the light, and cellular respiration occurs in both the dark and the light.
D)   Photosynthesis and cellular respiration occur in both the dark and the light.

Question 11

Which of the following statements is a correct distinction between autotrophs and heterotrophs?

Accepted Answer

A)   Autotrophs, but not heterotrophs, can nourish themselves beginning with CO₂ and other nutrients that are inorganic.
B)   Only heterotrophs require chemical compounds from the environment.
C)   Cellular respiration is unique to heterotrophs.
D)   Only heterotrophs have mitochondria.

Question 12

The reducing power for Calvin cycle reactions is provided by which of the following molecules?

Accepted Answer

A)   ATP
B)   NADH
C)   NADP⁺
D)   NADPH

Question 13

Why might the alternative pathways of photosynthesis using C₄ or CAM systems be described as metabolic compromises?

Accepted Answer

A)   Both pathways increase the rate of photosynthesis but also increase the rate of water loss.
B)   The CAM pathway allows more CO₂ into the plant but also increases the rate of water loss.
C)   The C₄ pathway decreases water loss but also increases the rate of photorespiration.
D)   Both pathways minimize photorespiration but also expend more ATP during carbon fixation.

Question 14

A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights that is set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask. The dissolved oxygen in the flask with algae will ________.

Accepted Answer

A)   always be higher
B)   always be lower
C)   be higher in the light, but the same in the dark
D)   be higher in the light, but lower in the dark

Question 15

Which of the following processes would be most directly affected if a thylakoid membrane is punctured so that the interior of the thylakoid is no longer separated from the stroma?

Accepted Answer

A)   splitting of water
B)   flow of electrons from photosystem II to photosystem I
C)   synthesis of ATP
D)   reduction of NADP⁺

Question 16

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in one hour. You find that 30,000 molecules of ATP were consumed, but only 20,000 molecules of NADPH were consumed. What is the source of the extra ATP molecules?

Accepted Answer

A)   photosystem II
B)   photosystem I
C)   cyclic electron flow
D)   linear electron flow

Question 17

What would be the expected effect on plants if the atmospheric CO₂ concentration was doubled?

Accepted Answer

A)   All plants would have faster growth rates.
B)   C₃ plants would have faster growth rates; C₄ plants would be minimally affected.
C)   C₄ plants would have faster growth rates; C₃ plants would be minimally affected.
D)   C₃ plants would have faster growth rates; C₄ plants would have slower growth rates.

Question 18

Which of the following molecules are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

Accepted Answer

A)   CO₂ and glucose
B)   H₂O and O₂
C)   ADP,  ᵢ, and NADP⁺
D)   ATP and NADPH

Question 19

Which of the following does not occur during the Calvin cycle?

Accepted Answer

A)   carbon fixation
B)   oxidation of NADPH
C)   release of oxygen
D)   regeneration of the CO₂ acceptor

Question 20

How is photosynthesis similar in C₄ plants and CAM plants?

Accepted Answer

A)   In both cases, only photosystem I is used.
B)   Both types of plants make sugar without the Calvin cycle.
C)   In both cases, rubisco is not used to fix carbon initially.
D)   Both types of plants make most of their sugar in the dark.

Exam 10: Photosynthesis

Which of the following processes would be most directly affected if a thylakoid membrane is punctured so that the interior of the thylakoid is no longer separated from the stroma?

Correct Answer
verified

In mechanism, photophosphorylation is most similar to

Correct Answer
verified

Which of the following does not occur during the Calvin cycle?

Correct Answer
verified

In mitochondria, an electron transport chain pumps protons from the matrix into the intermembrane space, whereas in chloroplasts, an electron transport chain pumps protons from the ________.

Correct Answer
verified

Under what conditions do photosynthesis and cellular respiration occur in plants?

Correct Answer
verified

What would be the expected effect on plants if the atmospheric CO₂ concentration was doubled?

Correct Answer
verified

The reducing power for Calvin cycle reactions is provided by which of the following molecules?

Correct Answer
verified

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in one hour. You find that 30,000 molecules of ATP were consumed, but only 20,000 molecules of NADPH were consumed. What is the source of the extra ATP molecules?

Correct Answer
verified

Why are the reaction centers of photosystems composed of several structurally different pigments?

Correct Answer
verified

The mechanism of photophosphorylation is most similar to which of the following processes?

Correct Answer
verified

Which of the following events accompanies absorption of energy by chlorophyll molecules of the reaction-center complex?

Correct Answer
verified

Compared to C₃ plants, C₄ plants ________.

Correct Answer
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Which of the following molecules are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

Correct Answer
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Correct Answer
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What happens to the free energy released as electrons are passed from photosystem II to photosystem I through a series of electron carriers?

Correct Answer
verified

P680⁺ is said to be the strongest biological oxidizing agent. Given its function, why is this necessary?

Correct Answer
verified

How is photosynthesis similar in C₄ plants and CAM plants?

Correct Answer
verified

Which of the following statements is a correct distinction between autotrophs and heterotrophs?

Correct Answer
verified

Why might the alternative pathways of photosynthesis using C₄ or CAM systems be described as metabolic compromises?

Correct Answer
verified

Correct Answer
verified

Exam 10: Photosynthesis

Which of the following processes would be most directly affected if a thylakoid membrane is punctured so that the interior of the thylakoid is no longer separated from the stroma?

Correct AnswerverifiedShow Answer

In mechanism, photophosphorylation is most similar to

Correct AnswerverifiedShow Answer

Which of the following does not occur during the Calvin cycle?

Correct AnswerverifiedShow Answer

In mitochondria, an electron transport chain pumps protons from the matrix into the intermembrane space, whereas in chloroplasts, an electron transport chain pumps protons from the ________.

Correct AnswerverifiedShow Answer

Under what conditions do photosynthesis and cellular respiration occur in plants?

Correct AnswerverifiedShow Answer

What would be the expected effect on plants if the atmospheric CO₂ concentration was doubled?

Correct AnswerverifiedShow Answer

The reducing power for Calvin cycle reactions is provided by which of the following molecules?

Correct AnswerverifiedShow Answer

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in one hour. You find that 30,000 molecules of ATP were consumed, but only 20,000 molecules of NADPH were consumed. What is the source of the extra ATP molecules?

Correct AnswerverifiedShow Answer

Why are the reaction centers of photosystems composed of several structurally different pigments?

Correct AnswerverifiedShow Answer

The mechanism of photophosphorylation is most similar to which of the following processes?

Correct AnswerverifiedShow Answer

Which of the following events accompanies absorption of energy by chlorophyll molecules of the reaction-center complex?

Correct AnswerverifiedShow Answer

Compared to C₃ plants, C₄ plants ________.

Correct AnswerverifiedShow Answer

Which of the following molecules are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

What happens to the free energy released as electrons are passed from photosystem II to photosystem I through a series of electron carriers?

Correct AnswerverifiedShow Answer

P680⁺ is said to be the strongest biological oxidizing agent. Given its function, why is this necessary?

Correct AnswerverifiedShow Answer

How is photosynthesis similar in C₄ plants and CAM plants?

Correct AnswerverifiedShow Answer

Which of the following statements is a correct distinction between autotrophs and heterotrophs?

Correct AnswerverifiedShow Answer

Why might the alternative pathways of photosynthesis using C₄ or CAM systems be described as metabolic compromises?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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