Which characteristic is shared by both photosynthesis and cellular respiration?

• A. Both convert glucose into carbon dioxide and water.
• B. Both involve the production of ATP through electron transport chains.
• C. Both occur only in the chloroplasts of plant cells.
• D. Both require sunlight as a direct energy source.

Answer: (B)

Verified step by step guidance

1. Understand the processes of photosynthesis and cellular respiration: Photosynthesis is the process by which plants convert light energy into chemical energy stored in glucose, while cellular respiration is the process by which cells break down glucose to produce ATP, the energy currency of the cell.
2. Identify the role of electron transport chains in both processes: In photosynthesis, the electron transport chain is part of the light-dependent reactions, where electrons are transferred to produce ATP and NADPH. In cellular respiration, the electron transport chain is located in the mitochondria and is used to generate ATP through oxidative phosphorylation.
3. Recognize that ATP production is a shared characteristic: Both photosynthesis and cellular respiration involve the production of ATP, although the mechanisms and locations differ. Photosynthesis produces ATP in the chloroplasts, while cellular respiration produces ATP in the mitochondria.
4. Eliminate incorrect options: For example, photosynthesis does not convert glucose into carbon dioxide and water; that is a characteristic of cellular respiration. Additionally, cellular respiration does not require sunlight as a direct energy source, and it occurs in mitochondria, not chloroplasts.
5. Conclude that the shared characteristic is the involvement of electron transport chains in ATP production: This is the correct answer because both processes rely on electron transport chains to facilitate the production of ATP, which is essential for cellular energy.