Question

The external factors that affect photosynthesis are number, size, age and orientation of leaves, mesophyll cells and chloroplasts and the amount of chlorophyll. The internal factors that affect photosynthesis are availability of sunlight, temperature, $CO_{2}$ concentration and water.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (D)

If both assertion and reason are false

Answer 2

Photosynthesis is underthe influence of several factors, both internal (plant) and external. The plant factors include the number, size, age and orientation of leaves, mesophyll cells and chloroplasts, internal $CO_{2}$ concentration and the amount of chlorophyll. The plant or internal factors are dependent on the genetic predisposition and the growth of the plant. The external factors include the availability of sunlight, temperature, $CO_{2}$ concentration and water. During photosynthesis, all these factors simultaneously affect its rate.