Worked examplesThree real photosynthesis questions
From the practice pool, not the mock papers — each with the reasoning that produces the answer.
90 practice questions sit on this single topic — enough that it is worth working through by topic rather than meeting it scattered through a unit review.
82% of them come with a figure. Reading the graph or diagram correctly is most of the work here before any content knowledge applies.
Visual Representations · with figure
A student refers to Figure 1 while analyzing a biochemical pathway model. Which statement is supported by the figure?
- AMarker A: The citric acid cycle oxidizes acetyl-CoA and transfers energy to electron carriers.
- BMarker B: Translation assembles polypeptides
- CMarker C: Description matches the Calvin cyclecorrect
- DMarker D: Glycolysis splits glucose and can occur without direct use of oxygen.
Why C is correct
Figure 1 must be used to determine which marker is supported by the visual model. Marker C: The Calvin cycle uses ATP and NADPH to help fix carbon dioxide into carbohydrate intermediates. The Calvin cycle occurs in the stroma and uses ATP and NADPH from the light reactions to fix carbon dioxide into organic molecules.
The evidence in the prompt matters before the topic label: "A diagram shows ATP and NADPH entering a cycle in the chloroplast stroma, while carbon dioxide is incorporated...". The supported answer is "Calvin cycle" because The Calvin cycle occurs in the stroma and uses ATP and NADPH from the light reactions to fix carbon dioxide into organic molecules. Distractors such as Glycolysis or Translation either ignore the stated pattern or name a related concept without matching the evidence.
Visual Representations · with figure
A student measured oxygen production by aquatic plants under different light colors. Which conclusion is best supported by the data? Use Figure 1 to answer the question.
- AOxygen production is unrelated to light availability.
- BBlue and red light support higher oxygen production than green light.correct
- CGreen light supports the highest photosynthetic rate.
- DPlants produce oxygen only when no light is present.
Why B is correct
The highest oxygen bubble counts are under blue and red light, while green and no-light conditions are lower. This supports greater photosynthetic activity under blue and red light.
The evidence in the prompt matters before the topic label: "A student measured oxygen production by aquatic plants under different light colors. Which conclusion is best...". The supported answer is "Blue and red light support higher oxygen production than green light" because The highest oxygen bubble counts are under blue and red light, while green and no-light conditions are lower. Distractors such as Oxygen production is unrelated to light availability or Green light supports the highest photosynthetic rate either ignore the stated pattern or name a related concept without matching the evidence.
Visual Representations · with figure
Based on Figure 1, which statement accurately explains the represented process?
- AMarker A: Light-dependent reactions occur at the thylakoid membranecorrect
- BMarker B: The Calvin cycle uses ATP and NADPH in the stroma to reduce carbon dioxide.
- CMarker C: Pigments absorb some wavelengths
- DMarker D: Stomata regulate gas exchange that supplies carbon dioxide for photosynthesis.
Why A is correct
Figure 1 must be used to determine which marker is supported by the visual model. Marker A: Thylakoid membranes organize light-dependent reactions that build a proton gradient for ATP production. Photosystems and electron transport proteins in the thylakoid membrane participate in light-dependent reactions that generate ATP and NADPH.
The evidence in the prompt matters before the topic label: "A chloroplast model labels the thylakoid membrane. Which process is most directly associated with this membrane". The supported answer is "Light-dependent reactions that produce ATP and NADPH" because Photosystems and electron transport proteins in the thylakoid membrane participate in light-dependent reactions that generate ATP and NADPH. Distractors such as citric acid cycle or Translation of all nuclear genes either ignore the stated pattern or name a related concept without matching the evidence.
90 questions on this topic, free to start.
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Last reviewed 2026-08-28. Topic and unit names follow the
College Board course framework. Question counts describe the PrepScore practice bank, not the exam.