What is the main idea described in a text about photosynthesis?

• A. Converts carbon dioxide and water into glucose and oxygen using light energy.
• B. Plants need sunlight to grow.
• C. Oxygen is the only product of photosynthesis.
• D. Photosynthesis happens in the roots.

Answer: (A)

Photosynthesis is the process where light energy is used to turn carbon dioxide and water into glucose and oxygen. The main idea is that light energy drives a chemical change that builds sugar (glucose) while releasing oxygen as a byproduct. In plants, this happens in chloroplasts and provides the energy and material for growth—the glucose stored in the plant and the oxygen that goes into the air. The overall idea is captured by the fact that carbon dioxide and water are the starting materials, light provides the energy, and glucose and oxygen are the end products.

Other statements don’t capture this core flow: sunlight is important for growth, but it’s not the defining description of the process; oxygen is produced but not the only product; and photosynthesis occurs in the leaves’ chloroplasts, not in the roots.