In the context of an introduction to photosynthesis, what role do animals play in the photosynthetic process in ecosystems?

• A. They produce oxygen as the primary product of photosynthesis, which plants then consume.
• B. They directly convert light energy into chemical energy by performing photosynthesis in chloroplasts.
• C. They supply carbon dioxide through respiration, which plants can use as a reactant for photosynthesis.
• D. They absorb sunlight and transfer that energy to plants to drive the light-dependent reactions.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the process of photosynthesis, which primarily occurs in plants, algae, and some bacteria. Photosynthesis converts light energy into chemical energy, producing oxygen and glucose from carbon dioxide and water.
2. Step 2: Recognize that animals do not perform photosynthesis because they lack chloroplasts, the organelles where photosynthesis takes place.
3. Step 3: Identify the role of animals in the ecosystem related to photosynthesis. Animals perform cellular respiration, which consumes oxygen and releases carbon dioxide as a byproduct.
4. Step 4: Connect how the carbon dioxide released by animals during respiration serves as a crucial reactant for plants during photosynthesis, enabling plants to produce glucose and oxygen.
5. Step 5: Conclude that animals support the photosynthetic process indirectly by supplying carbon dioxide, which plants use to carry out photosynthesis, maintaining the balance of gases in the ecosystem.