Experiment: Chloroplasts were isolated and exposed to light with and without CO₂. ATP production was measured.Observation: ATP was produced with light even in the absence of CO₂.Question: What does this show?
Correct answer: C. Light reactions occur independently of carbon fixation.
- A. CO₂ is required for ATP synthesis.
- B. ATP forms only during the dark phase.
- C. Light reactions occur independently of carbon fixation.
- D. Photosynthesis stops without CO₂.
Explanation
The correct answer is that light reactions occur independently of carbon fixation. This is supported by the observation from the experiment where ATP was produced with light even in the absence of CO₂. The other options are incorrect because they do not align with the observed results of the experiment.
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About Scientific Reasoning
Scientific reasoning evaluates hypotheses through observations, variables, controls, measurements and experimental results. Questions involve identifying independent and dependent variables, recognising a fair test, interpreting tables or graphs, distinguishing evidence from opinion, and deciding whether data supports, rejects or leaves a hypothesis unresolved.
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