Question

The source of oxygen evolved during photosynthesis is ................

• A. light
• B. chlorophyll
• C. CO\textsubscript{2}
• D. water

Hint:

In photosynthesis, remember that water is split to release oxygen during the light-dependent reactions, and carbon dioxide is used to form glucose in the Calvin cycle.

Answer 1

The Correct Option is D

Step 1: Understanding the process of photosynthesis.
Photosynthesis is a process in which plants use light energy to convert carbon dioxide and water into glucose and oxygen. The oxygen produced is a result of the splitting of water molecules during the light-dependent reactions.
Step 2: Analyzing the options.
(A) light: Light provides the energy required for photosynthesis, but it is not the source of the oxygen evolved.
(B) chlorophyll: Chlorophyll is involved in capturing light energy but is not directly responsible for the oxygen produced.
(C) CO\textsubscript{2:} Carbon dioxide is involved in the formation of glucose, not in the release of oxygen.
(D) water: Correct — Water is the source of oxygen in photosynthesis, as it is split during the light-dependent reactions to release oxygen.
Step 3: Conclusion.
The correct answer is (D) water, as oxygen is released from water molecules during photosynthesis.