Question

The correct statement of dark reaction is

• A. It occur in presence of light only
• B. It occur in absence of light only
• C. It is independent of light
• D. All of these

Answer 1

The correct option is B

It occur in absence of light only

The correct option is B:
The explanation for the correct option:

1. Photosynthesis is the process that involves the synthesis of organic food from inorganic substances with the help of chlorophyll in presence of sunlight.
2. Photosynthesis occurs in two phases, these are the light reaction and the dark reaction.
3. Dark reaction:
4. Dark reaction occurs in the stroma.
   • It involves the conversion of carbon dioxide to glucose by the enzyme rubisco in the Calvin-Benson cycle.
   • The energy molecules consumed are ATP and NADPH₂, these bring about reactions.
   • This reaction takes place in absence of light, hence it is known as a dark reaction.

The explanation for incorrect options:
Option A:
The light reaction of the photosynthesis process takes place in the presence of light.

Option C:
The dark reaction will be unable to synthesize any product without sunlight because the energy molecules utilized in the form of ATP and NADPH₂ are produced during the light reaction which occurs in the presence of light.

Final answer: Dark reaction occurs in the absence of light.