During photosynthesis, the oxygen in glucose is from?

• (a) Water
• (b) Carbon dioxide
• (c) Both from CO₂ and water
• (d) Oxygen in air

During photosynthesis, the oxygen in glucose primarily comes from water. This process involves plants using sunlight to convert carbon dioxide and water into glucose and oxygen. The correct answer is (a) Water.

How Photosynthesis Works

In photosynthesis, plants absorb sunlight through their leaves. This energy helps split water molecules into hydrogen and oxygen. The hydrogen combines with carbon dioxide to form glucose, while the oxygen is released as a byproduct.

Key Components of Photosynthesis

• Water (H₂O): Provides oxygen and hydrogen.
• Carbon Dioxide (CO₂): Supplies carbon for glucose.
• Sunlight: Powers the entire process.

Thus, the oxygen produced during photosynthesis originates from the water molecules that plants take in. This is a crucial aspect of how plants contribute to the Earth's oxygen supply.