Which of the following factors is not necessary for photosynthesis?

Step 1: Analyze the question We are asked which factor is not needed for photosynthesis. So we look for the option that plays no role in the process.

Step 2: Recall the concept Photosynthesis is the process by which green plants make food (glucose) using light energy.

Word equation: Carbon (IV) oxide + Water → (sunlight, chlorophyll) → Glucose + Oxygen

Chemical equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ (in the presence of light and chlorophyll)

Step 3: Check each option

• A. Water: a raw material. It is needed, and its splitting in the light reaction supplies hydrogen. ✔ Necessary
• B. Carbon (IV) oxide: a raw material. It is the source of carbon for making glucose. ✔ Necessary
• C. Wind: it plays no part in the reactions of photosynthesis. Wind helps with things like transpiration and pollen or seed dispersal, but it is not required. ✘ Not necessary
• D. Sunlight: the energy source that drives the process. ✔ Necessary

Step 4: Answer The factor that is not necessary for photosynthesis is wind, which is option C.

Exam tip: Remember the four essentials as C-W-L-C: CO₂, Water, Light, Chlorophyll. Anything outside this list, such as wind, soil type, or oxygen, is not required for photosynthesis itself. Oxygen is a product, not a requirement.