Explanation

Genetic predisposition. The rate of photosynthesis is very important in determining the yield of plants including crop plants. Photosynthesis is under the influence of several factors, both internal (plant) and external. The plant factors includes the number, size, age and orientation of leaves, mesophyll cells and chloroplast, 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