Question

which statement describes the relationship between plants, animals, and the carbon cycle?
○ plants use carbon and release oxygen, and animals release carbon and use oxygen.
○ animals fix carbon and release oxygen, and plants release carbon and use oxygen.
○ animals fix carbon through respiration, and plants fix carbon through photosynthesis.
○ plants use carbon when they decompose, and animals release carbon when they decompose.

Explanation:

To solve this, we analyze each option based on photosynthesis (plants) and respiration (animals) in the carbon cycle:

• Option 1: Plants perform photosynthesis, using carbon dioxide (carbon) and releasing oxygen. Animals perform respiration, releasing carbon dioxide (carbon) and using oxygen. This matches the carbon cycle processes.
• Option 2: Animals do not fix carbon or release oxygen in the way described; plants fix carbon (via photosynthesis) and release oxygen, while animals release carbon (respiration) and use oxygen. So this is incorrect.
• Option 3: Animals release carbon through respiration (don't fix carbon), and plants fix carbon through photosynthesis. The description of animals fixing carbon is wrong.
• Option 4: When plants decompose, they release carbon (not use), and animals also release carbon when decomposing. The description of plants using carbon during decomposition is wrong.

Answer:

A. Plants use carbon and release oxygen, and animals release carbon and use oxygen.