Question

which is common to both photosynthesis and respiration? a nadh is produced by krebs cycle. b chemical energy is produced in the form of atp. c two atp are formed by the process of glycolysis. d glyceraldehyde-3 phosphate is produced by calvin cycle.

Explanation:

To solve this problem, we analyze each option by recalling the processes of photosynthesis and respiration:

Step 1: Analyze Option A

The Krebs cycle (part of cellular respiration) produces NADH, but photosynthesis does not involve the Krebs cycle. So this is not common to both.

Step 2: Analyze Option B

• Photosynthesis: In the light-dependent reactions, ATP is produced (via photophosphorylation) to power the light-independent (Calvin cycle) reactions.
• Respiration: In glycolysis, the Krebs cycle, and oxidative phosphorylation, ATP is produced to supply energy for cellular processes.

Thus, both processes produce chemical energy in the form of ATP.

Step 3: Analyze Option C

Glycolysis (part of respiration) produces a net of 2 ATP, but photosynthesis does not involve glycolysis. So this is not common to both.

Step 4: Analyze Option D

Glyceraldehyde-3-phosphate (G3P) is produced in the Calvin cycle (photosynthesis), but respiration does not produce G3P. So this is not common to both.

Answer:

B