Describe any two factors affecting the rate of photosynthesis.

Explanation

The process of photosynthesis is affected by a number of factors. These factors are as follows:
1. Light (2) `CO_(2)` concentration (3) Temperature (4) Water.
1. Light: There are three aspects of light as a factor, viz., quality of light, intensity of light and duration of light which affect the rate of phososynthesis. The rate of photosynthesis is more is red and blue light and less or negligible in green light.
The duration of light affects fthe rate of photosynthesis. Greater the duration, greater is te rato of photosynthesis. Similarly more the light intensity greater is the rate of photosynthesis.
2. `CO_(2)` concentration : `CO_(2)` being one of the raw materials for photosynthesis its concentration affects the rate of the proces considerable. The normal concentration of `CO_(2)` in the atmosphere lies between 0.03% and 0.04%. Increase in concentration of `CO_(2)` up to 0.05% results in an increase in the rate of photosynthesis.
3. Temperature: The rate of photosynthesis is controlled by temperature also. The temperature optimum for photosynthesis depends upon the habitat of the plant. Tropical plants need a higher temperature optimum as compared to temperate plants which need lower temperature optimum.
4. Water: Water being one of the raw materials for photiosynthesis affects the rate of photosynthesis . Water stress causes closure of stomata which is turn reduces the availability of `CO_(2)` for photosynthesis.