Answer:
D) The hydrogen and oxygen atoms of water are split in the light reactions, and oxygen is released. In the Calvin cycle, hydrogen atoms join with the carbon and oxygen atoms of carbon dioxide to form carbohydrates.
Explanation:
Photosynthesis is the process by which plants produce carbohydrates (sugars) from carbon dioxide in the atmosphere and water using the energy of sunlight. The process of photosynthesis occurs in two stages: (i) the light-dependent stage and (ii) the light-independent stage.
Light reactions: In this stage, the hydrogen and oxygen atoms of water are split in the light reactions, and oxygen is released. Also, the energy storage molecule ATP and the reduced electron carrier NADPH are produced.
Light-independent reaction or Calvin cycle: in this stage, carbon atoms from CO₂ are incorporated into ribulose-5-phosphate and used to produce glyceraldehyde-3-phosphate, a three-carbon sugar using the energy of ATP and NADPH from the light reactions. Essentially, hydrogen atoms join with the carbon and oxygen atoms of carbon dioxide to form carbohydrates.
