Which of the following incorrectly describes mechanisms of CO\(_2\) transport in plants during photosynthesis?

• A. CO\(_2\) is transported from the atmosphere into the leaf through stomata by diffusion.
• B. CO\(_2\) dissolves in the aqueous phase of the mesophyll cell cytoplasm before entering the chloroplast.
• C. CO\(_2\) is fixed by the enzyme RuBisCO in the Calvin cycle.
• D. CO\(_2\) is actively pumped into chloroplasts using ATP.

Answer: (D)

Verified step by step guidance

1. Understand the context: The question is about mechanisms of CO\(_2\) transport in plants during photosynthesis. Photosynthesis involves the uptake of CO\(_2\) from the atmosphere, its diffusion into the leaf, and its fixation in the Calvin cycle. The question asks which statement is incorrect.
2. Review the first statement: 'CO\(_2\) is transported from the atmosphere into the leaf through stomata by diffusion.' This is correct because CO\(_2\) enters the leaf through stomata via passive diffusion, driven by a concentration gradient.
3. Review the second statement: 'CO\(_2\) dissolves in the aqueous phase of the mesophyll cell cytoplasm before entering the chloroplast.' This is also correct because CO\(_2\) dissolves in the cytoplasm and diffuses into the chloroplast where photosynthesis occurs.
4. Review the third statement: 'CO\(_2\) is fixed by the enzyme RuBisCO in the Calvin cycle.' This is correct because RuBisCO is the enzyme responsible for fixing CO\(_2\) into organic molecules during the Calvin cycle.
5. Review the fourth statement: 'CO\(_2\) is actively pumped into chloroplasts using ATP.' This is incorrect because CO\(_2\) enters the chloroplast by diffusion, not active transport, and ATP is not used for this process. This makes the fourth statement the correct answer to the question.