Question

which statement accurately describes the energy needs for photosynthesis and cellular respiration?
a) light energy is needed for cellular respiration but not for photosynthesis.
b) chemical energy in the form of glucose is needed for photosynthesis, and solar energy is needed for cellular respiration.
c) solar energy is needed for photosynthesis, and chemical energy in the form of glucose is needed for cellular respiration.
d) chemical energy in the form of glucose is needed for both cellular respiration and photosynthesis

Explanation:

To solve this, we recall the energy sources for photosynthesis and cellular respiration. Photosynthesis uses light energy to convert CO₂ and H₂O into glucose (storing chemical energy). Cellular respiration breaks down glucose (chemical energy) to release energy (ATP) for the cell.

• Option A: Light energy is for photosynthesis, not cellular respiration (which uses chemical energy from glucose), so A is wrong.
• Option B: Photosynthesis needs light, not chemical energy (glucose is a product, not a reactant for photosynthesis), so B is wrong.
• Option C: Light energy is used in photosynthesis to make glucose, and chemical energy (from glucose) is used in cellular respiration. This matches the processes.
• Option D: Chemical energy (glucose) is a product of photosynthesis, not a reactant, so it can't be used for photosynthesis. So D is wrong.

Answer:

C. Light energy is needed for photosynthesis, and chemical energy in the form of glucose is needed for cellular respiration