Question

Assertion (A): Photosynthesis occurs in the presence of oxygen.

Reason (R): Oxygen is a necessary reactant for the synthesis of glucose.

Options

• Both A and R are true and R is the correct explanation of A.

• Both A and R are true but R is not the correct explanation of A.

• A is true but R is false.

• A is false but R is true.

Answer 1

A is true but R is false.

Explanation:

The assertion is true because photosynthesis can successfully occur in the presence of oxygen (normal atmospheric conditions), even though oxygen is not needed for the process to happen. However, the reason is completely false because oxygen is a by-product released during the light reactions of photosynthesis, not a necessary reactant. The actual starting materials required to synthesise glucose are carbon dioxide (CO₂) and water (H₂O).