Final answer:
In photosynthesis, water molecules are split into hydrogen and oxygen atoms. Hydrogen is used to generate ATP and NADPH for the Calvin cycle, while oxygen is released as a byproduct. Correct answer is A: Hydrogen and oxygen.
Step-by-step explanation:
In photosynthesis, water molecules are split into hydrogen and oxygen atoms. The correct answer to the question is: A: Hydrogen and oxygen. The process occurs in the light-dependent reactions of photosynthesis, where water (H₂O) is split to form oxygen (O₂) and hydrogen ions (H+). This reaction is crucial for replacing the electrons that are excited and passed along the electron transport chain within the thylakoid membranes of the chloroplasts.
The breakdown of water molecules involves the rearrangement of the atoms, where two water molecules form one oxygen molecule and two hydrogen molecules, shown by the equation 2H₂O(l) → 2H₂(g) + O₂(g). These hydrogen atoms can then be used to generate ATP and NADPH, which are essential for the synthesis of sugars/carbohydrates during the Calvin cycle. So, the Correct answer is A: Hydrogen and oxygen.