How do plants and animals help to maintain a balance of carbon dioxide (\(\mathrm{CO_2}\)) in the atmosphere?

• A. Both plants and animals only absorb \(\mathrm{CO_2}\) from the atmosphere.
• B. Plants and animals both release \(\mathrm{CO_2}\) during photosynthesis.
• C. Animals convert \(\mathrm{CO_2}\) into oxygen during respiration.
• D. Plants absorb \(\mathrm{CO_2}\) during photosynthesis, while animals release \(\mathrm{CO_2}\) during respiration.

Answer: (D)

Verified step by step guidance

1. Understand the role of photosynthesis in plants: Plants absorb carbon dioxide (\(\mathrm{CO_2}\)) from the atmosphere during photosynthesis. This process uses \(\mathrm{CO_2}\), water, and sunlight to produce glucose and oxygen. The chemical equation for photosynthesis is: \$6\mathrm{CO_2} + 6\mathrm{H_2O} \xrightarrow{light} \mathrm{C_6H_{12}O_6} + 6\mathrm{O_2}$.
2. Recognize the role of cellular respiration in animals: Animals release carbon dioxide (\(\mathrm{CO_2}\)) into the atmosphere during cellular respiration. This process breaks down glucose in the presence of oxygen to produce energy, carbon dioxide, and water. The chemical equation for cellular respiration is: \(\mathrm{C_6H_{12}O_6} + 6\mathrm{O_2} \rightarrow 6\mathrm{CO_2} + 6\mathrm{H_2O} + \text{energy}\).
3. Identify the balance between photosynthesis and respiration: Plants absorb \(\mathrm{CO_2}\) during photosynthesis, reducing its concentration in the atmosphere, while animals release \(\mathrm{CO_2}\) during respiration, increasing its concentration. This creates a natural cycle that helps maintain the balance of \(\mathrm{CO_2}\) in the atmosphere.
4. Clarify misconceptions: Plants do not release \(\mathrm{CO_2}\) during photosynthesis; instead, they release oxygen (\(\mathrm{O_2}\)). Similarly, animals do not convert \(\mathrm{CO_2}\) into oxygen during respiration; they release \(\mathrm{CO_2}\) as a byproduct of energy production.
5. Summarize the correct answer: Plants absorb \(\mathrm{CO_2}\) during photosynthesis, while animals release \(\mathrm{CO_2}\) during respiration. This complementary relationship helps regulate atmospheric \(\mathrm{CO_2}\) levels.