Define the law of limiting factors.

Explanation

### Step-by-Step Text Solution:

1. **Definition of the Law of Limiting Factors**: The law of limiting factors was proposed by scientist F.F. Blackman in 1905. It states that when a process (such as photosynthesis) is influenced by multiple factors, the rate of that process is determined by the factor that is closest to its minimum value.

2. **Application to Photosynthesis**: In the context of photosynthesis, several factors can influence the rate, including light intensity, carbon dioxide concentration, and water availability.

3. **Example Explanation**: For instance, if the light intensity is sufficient to utilize 5 milligrams of CO2, increasing the concentration of CO2 will initially increase the rate of photosynthesis. However, once the light intensity becomes the limiting factor (because it can only utilize 5 milligrams of CO2), further increases in CO2 concentration will not affect the rate of photosynthesis.

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