Which one of the following is limiting rate of photosynthesis in nature

Options

A. Light
B. `CO_(2)`
C. `O_(2)`
D. Both A and B

Answer

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**: Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose, using carbon dioxide and water, while releasing oxygen as a byproduct.

2. **Identifying Factors Affecting Photosynthesis**: Several factors can influence the rate of photosynthesis, including light intensity, carbon dioxide concentration, temperature, and the availability of water.

3. **Evaluating the Options**: The question provides four options: light, carbon dioxide, oxygen, and both A and B. We need to determine which of these is the limiting factor in nature.

4. **Analyzing Carbon Dioxide**: The concentration of carbon dioxide in the atmosphere is relatively low, typically between 0.03% and 0.04%. This low concentration can limit the rate of photosynthesis because plants require carbon dioxide to produce glucose.

5. **Impact of Carbon Dioxide Levels**: An increase in carbon dioxide concentration up to about 0.05% can enhance the rate of photosynthesis. However, concentrations above this level can be harmful over extended periods.

6. **Evaluating Light and Oxygen**: While light is essential for photosynthesis, it is generally abundant and not considered a limiting factor in most natural environments. Oxygen, on the other hand, is a byproduct of photosynthesis and does not limit the process.

7. **Conclusion**: Based on the analysis, carbon dioxide is identified as the major limiting factor affecting the rate of photosynthesis in nature.

**Final Answer**: The correct option is carbon dioxide.

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