What do you think can affect the rate of photosynthesis?

Answer 1

The rate of photosynthesis will almost always decrease by whichever of several factors is lowest. Some of these include:

1)Sunlight - its Intensity & wavelength.

2)Temperature

3)CO2 and O2 - availability

Sunlight

Generally the more light there is the more photosynthesis occurs. This is true up to a point where the plant has reached maximum photosynthesis levels, so any increase in light intensity will not affect the plant further.

Temperature

Generally a higher temperature is better than cold temperatures for photosynthesis. However if it is humid and the air is saturated with water vapor, photosynthesis is limited. This is because the water vapor being expelled cannot leave and go into the air, as there isn't a concentration difference for it to diffuse across. So the water vapor sits in the leaf, stopping photosynthesis.

CO2

Basically the more CO2 in the air, the better the rate of photosynthesis. Of course CO2 is taken in during the daytime, and if its content was less that normal, photosynthesis couldn't happen normally. Fertilizers increase the number of soil fungi and bacteria, thus increasing the levels of CO2 from their respiration and decomposition processes.

Water and CO2

Plants need water for photosynthesis. If they lack it, they wilt. When they have a deficiency of water, their stoma close, so CO2 cannot diffuse into the leaves. So CO2 is also the limiting factor, although it is as a result of lack of water.

Answer 2

You need three things to have photosynthesis: water, carbon dioxide, and light. Take any one away, and you slow down the rate.

Answer 3

light