Explanation:
There are several ways of measuring the rate of photosynthesis in the lab. These include:
the rate of oxygen output
the rate of carbon dioxide uptake
the rate of carbohydrate production
These are not perfect methods as the plant will also be respiring, which will use up some oxygen and carbohydrate and increase carbon dioxide output.
Several factors can affect the rate of photosynthesis:
light intensity
carbon dioxide concentration
temperature
The amount of chlorophyll also affects the rate of photosynthesis:
plants in lighting conditions unfavourable for photosynthesis may synthesise more chlorophyll, to absorb the light required
the effects of some plant diseases affect the amount of chlorophyll, and therefore the ability of a plant to photosynthesise
