AP BIO TEST, AP BIO COLLEGE BOARD
UNIT 3 EXAM 2025 QUESTIONS AND
ANSWERS
What does the chemiosmotic process in chloroplasts involve? - ANS A) establishment of a
proton gradient
In glycolysis, for each molecule of glucose oxidized to pyruvate - ANS B) 2 molecules of ATP
are used and 4 molecules of ATP are produced.
In chemiosmotic phosphorylation, what is the most direct source of energy that is used to
convert ADP + Pi to ATP? - ANS D) energy released from movement of protons through ATP
synthase
Which statement describes the functioning of photosystem II? - ANS D) The electron
vacancies in P680 are filled by electrons derived from water.
The primary role of oxygen in cellular respiration is to - ANS B) act as an acceptor for
electrons and hydrogen, forming water.
During aerobic respiration, which of the following directly donates electrons to the electron
transport chain at the lowest energy level? - ANS E) FADH2
Which of the following is likely to lead to an increase in the concentration of ATP in a cell? -
ANS B) an increase in a cell's catabolic activity
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, What wavelength of light in the figure is most effective in driving photosynthesis? - ANS A)
420 mm
Figure 10.1 shows the absorption spectrum for chlorophyll a and the action spectrum for
photosynthesis. Why are they different? - ANS D) Other pigments absorb light in addition to
chlorophyll a.
The oxygen consumed during cellular respiration is involved directly in which process or event?
- ANS B) accepting electrons at the end of the electron transport chain
In a plant cell, where are the ATP synthase complexes located? - ANS D) A and C....thylakoid
membrane & plasma membrane
Where does the Calvin cycle take place? - ANS A) stroma of the chloroplast
Photorespiration lowers the efficiency of photosynthesis by preventing the formation of -
ANS B) 3-phosphoglycerate molecules
Which metabolic pathway is common to both cellular respiration and fermentation? - ANS D)
glycolysis
Why are C4 plants able to photosynthesize with no apparent photorespiration? - ANS B)
They use PEP carboxylase to initially fix CO2 .
What are the products of linear photophosphorylation? - ANS C) ATP and NADPH
The ATP made during glycolysis is generated by - ANS A) substrate-level phosphorylation.
2 Copyright ©2025 BRAINBARTER ALL RIGHTS RESERVED
UNIT 3 EXAM 2025 QUESTIONS AND
ANSWERS
What does the chemiosmotic process in chloroplasts involve? - ANS A) establishment of a
proton gradient
In glycolysis, for each molecule of glucose oxidized to pyruvate - ANS B) 2 molecules of ATP
are used and 4 molecules of ATP are produced.
In chemiosmotic phosphorylation, what is the most direct source of energy that is used to
convert ADP + Pi to ATP? - ANS D) energy released from movement of protons through ATP
synthase
Which statement describes the functioning of photosystem II? - ANS D) The electron
vacancies in P680 are filled by electrons derived from water.
The primary role of oxygen in cellular respiration is to - ANS B) act as an acceptor for
electrons and hydrogen, forming water.
During aerobic respiration, which of the following directly donates electrons to the electron
transport chain at the lowest energy level? - ANS E) FADH2
Which of the following is likely to lead to an increase in the concentration of ATP in a cell? -
ANS B) an increase in a cell's catabolic activity
1 Copyright ©2025 BRAINBARTER ALL RIGHTS RESERVED
, What wavelength of light in the figure is most effective in driving photosynthesis? - ANS A)
420 mm
Figure 10.1 shows the absorption spectrum for chlorophyll a and the action spectrum for
photosynthesis. Why are they different? - ANS D) Other pigments absorb light in addition to
chlorophyll a.
The oxygen consumed during cellular respiration is involved directly in which process or event?
- ANS B) accepting electrons at the end of the electron transport chain
In a plant cell, where are the ATP synthase complexes located? - ANS D) A and C....thylakoid
membrane & plasma membrane
Where does the Calvin cycle take place? - ANS A) stroma of the chloroplast
Photorespiration lowers the efficiency of photosynthesis by preventing the formation of -
ANS B) 3-phosphoglycerate molecules
Which metabolic pathway is common to both cellular respiration and fermentation? - ANS D)
glycolysis
Why are C4 plants able to photosynthesize with no apparent photorespiration? - ANS B)
They use PEP carboxylase to initially fix CO2 .
What are the products of linear photophosphorylation? - ANS C) ATP and NADPH
The ATP made during glycolysis is generated by - ANS A) substrate-level phosphorylation.
2 Copyright ©2025 BRAINBARTER ALL RIGHTS RESERVED
