The correct answer is Option 3. Explanation & Key Takeaways: Photosynthesis: • The process of synthesis of food from carbon dioxide and water that occurs in the presence of sunlight is called photosynthesis. • It is a one-of-a-kind process on the planet. • Solar energy is collected by the leaves and stored in the plant as nourishment. • In the presence of sunshine, chlorophyll-containing cells in leaves synthesise carbohydrates. • The process can be represented in an equation: Carbon Dioxide + Water → Carbohydrate + Oxygen • During the process, oxygen is released. • The presence of starch in leaves indicates the occurrence of photosynthesis. Starch is also a carbohydrate. Hence option 3 is correct. Related Concepts: • Leaves are an important site for photosynthesis. • Chlorophyll is a green pigment found in the leaves. It aids leaves in absorbing solar energy. • Aside from leaves, photosynthesis occurs in other green components of the plant, such as green stems and green branches. • To decrease water loss through transpiration, desert plants grow scale or spine-like leaves. • These plants have photosynthesis-capable green stems.