How are respiration and photosynthesis related to each other?

• A. Respiration and photosynthesis are unrelated metabolic processes.
• B. The products of photosynthesis serve as the reactants for respiration, and vice versa.
• C. Photosynthesis releases carbon dioxide, while respiration absorbs it.
• D. Both processes only occur in animal cells.

Answer: (B)

Verified step by step guidance

1. Understand the basic definitions: Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose, using carbon dioxide and water as reactants. Respiration is the process by which cells break down glucose to release energy in the form of ATP, using oxygen and producing carbon dioxide and water as byproducts.
2. Recognize the relationship between the two processes: Photosynthesis produces glucose and oxygen, which are the reactants needed for cellular respiration. Conversely, respiration produces carbon dioxide and water, which are the reactants needed for photosynthesis.
3. Analyze the chemical equations: Photosynthesis can be represented as $C_6{H}_{12}{O}_6+6O\to 6\mathrm{CO}{2}_2+6H{2}_{2}O$, while respiration is essentially the reverse of this equation.
4. Clarify the role of carbon dioxide and oxygen: Photosynthesis absorbs carbon dioxide and releases oxygen, while respiration absorbs oxygen and releases carbon dioxide. This creates a cyclical exchange of gases between organisms and the environment.
5. Debunk misconceptions: Photosynthesis occurs in plant cells, algae, and some bacteria, not animal cells. Respiration occurs in all living cells, including both plant and animal cells. Both processes are interconnected and essential for life on Earth.