Which of the following statements is correct with respect to Blackman's law of limiting factor ?

Options

A. Only one factor can be limited in photosynthesis
B. Photosynthesis consists of a light and dark reaction
C. The trapping of light by chloroplast is temperature dependent
D. The trapping of light by chloroplast can occur only if `CO_(2)` is present

Answer

To solve the question regarding Blackman's law of limiting factor, we need to analyze each option provided and understand the principles behind Blackman's law.

### Step-by-Step Solution:

1. **Understanding Blackman's Law of Limiting Factor**:
- Blackman's law states that the rate of photosynthesis is determined by the factor that is in the least supply (the limiting factor). This means that even if other factors are abundant, the one that is scarce will limit the overall rate of photosynthesis.

2. **Analyzing the Options**:
- **Option A**: "Only one factor can be limited in photosynthesis."
- This aligns with Blackman's law, as it emphasizes that the rate of photosynthesis is controlled by the limiting factor, which is the one factor that is in short supply.

- **Option B**: "Photosynthesis consists of a light and a dark reaction."
- While this statement is true, it does not directly relate to Blackman's law of limiting factors.

- **Option C**: "The trapping of light by chloroplast is temperature dependent."
- This statement is also true but does not specifically address the concept of limiting factors.

- **Option D**: "The trapping of light by the chloroplast can occur only if carbon dioxide is present."
- This is incorrect because light trapping can occur independently of carbon dioxide levels; carbon dioxide is not a prerequisite for light absorption.

3. **Conclusion**:
- Based on the analysis, **Option A** is the correct statement regarding Blackman's law of limiting factor, as it correctly reflects the principle that only one factor can limit the rate of photosynthesis at any given time.

### Final Answer:
**Option A: Only one factor can be limited in photosynthesis.**