If the temperature is increased (above `35^(@)C`)

Options

A. Rate of photosynthesis will decline earlier than that of respiration
B. Rate of respiration will decline earlier than that of photosynthesis
C. There is no fixed pattern
D. Both decline simultaneously.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks what happens to the rates of photosynthesis and respiration when the temperature is increased above 35°C.

2. **Identifying Key Concepts:**
- Photosynthesis and respiration are both affected by temperature.
- There is an optimum temperature range for photosynthesis, which is typically between 25°C and 35°C.

3. **Effects of Temperature on Photosynthesis:**
- At temperatures below 0°C, enzymes involved in photosynthesis stop functioning, halting the process.
- As the temperature increases beyond the optimum range (above 35°C), the enzymes can become denatured, leading to a decline in the rate of photosynthesis.

4. **Effects of Temperature on Respiration:**
- Respiration also depends on temperature, but its rate generally declines at high temperatures, although it is less sensitive to temperature changes compared to photosynthesis.

5. **Comparative Analysis:**
- When the temperature exceeds 35°C, the rate of photosynthesis declines earlier than that of respiration due to the sensitivity of photosynthetic enzymes to heat.
- Eventually, both processes will decline, but photosynthesis is affected first.

6. **Conclusion:**
Based on the analysis, the correct answer is that the rate of photosynthesis will decline earlier than that of respiration when the temperature is increased above 35°C.

**Final Answer:**
The rate of photosynthesis will decline earlier than that of respiration.

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