Q. Assertion: The external factors that affect photosynthesis are number, size, age and orientation of leaves, mesophyll cells and chloroplasts and the amount of chlorophyll.
Reason :The internal factors that affect photosynthesis are availability of sunlight, temperature, concentration and water.

 2754  197 Photosynthesis in Higher Plants Report Error

Solution:

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 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, concentration and water. During photosynthesis, all these factors simultaneously affect its rate.