The main raw materials required for photosynthesis are

Step 1: Analyze the question The question asks for the raw materials (the reactants or inputs) of photosynthesis. These are the substances the plant takes in and uses to make food.

Step 2: Explain the concept Photosynthesis is the process by which green plants make glucose using light energy trapped by chlorophyll.

Word equation:

carbon dioxide + water → (light energy, chlorophyll) → glucose + oxygen

Chemical equation:

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Step 3: Work through the options

• A. Oxygen and water: Water is a raw material, but oxygen is a product, not a raw material. ✗
• B. Oxygen and carbon dioxide: Carbon dioxide is a raw material, but oxygen is a product. ✗
• C. Oxygen and chlorophyll: Oxygen is a product, and chlorophyll is a catalyst-like pigment that traps light. It is not a raw material. ✗
• D. Carbon dioxide and water: Both are the reactants that are absorbed from the environment. Carbon dioxide enters through the stomata, and water is absorbed by the roots. ✓

Step 4: Answer The correct option is D. carbon dioxide and water.

Exam tip: Remember that light and chlorophyll are conditions or requirements for photosynthesis, not raw materials. Oxygen and glucose are the products. A quick memory trick is "CO₂ and H₂O go in, glucose and O₂ come out."