Question

2
what statement best compares photosynthesis and cellular respiration?
a. photosynthesis only takes place in the light, while cellular respiration takes place in the light and dark.
b. both photosynthesis and cellular respiration take place during the light and during the dark.
c. photosynthesis breaks down sugars to release energy, while cellular respiration stores energy as sugars.
d. both photosynthesis and cellular respiration break down sugars to release chemical energy.

Explanation:

• Option A: Photosynthesis requires light (as it uses light energy to convert CO₂ and H₂O to glucose), while cellular respiration (which breaks down glucose to release energy) occurs continuously, in light or dark. This is correct.
• Option B: Photosynthesis needs light, so it doesn't occur in the dark. Eliminate B.
• Option C: Photosynthesis stores energy as sugars (by making glucose), and cellular respiration breaks down sugars to release energy. This is reversed. Eliminate C.
• Option D: Photosynthesis synthesizes (makes) sugars, while cellular respiration breaks them down. Eliminate D.

Answer:

A. Photosynthesis only takes place in the light, while cellular respiration takes place in the light and dark.