In Opuntia, leaves are reduced to spines. This is an adaptation to

Options

A. minimise water loss through transpiration
B. maximise water absorption from atmosphere
C. maximise the rate of photosynthesis
D. minimise the rate of photosynthesis

Answer

**Step-by-Step Solution:**

1. **Identify the Organism**: The question refers to Opuntia, which is a genus of cacti commonly found in desert environments.

2. **Understand the Adaptation**: In Opuntia, the leaves are reduced to spines. This is a significant adaptation for survival in harsh environments.

3. **Reason for Leaf Modification**: The primary reason for this adaptation is to minimize water loss. In desert conditions, water is scarce, and plants must conserve as much water as possible.

4. **Mechanism of Water Loss**: Plants typically lose water through a process called transpiration, which occurs through their leaves. By reducing the leaves to spines, Opuntia significantly reduces the surface area available for transpiration.

5. **Additional Adaptations**: While the question focuses on the reduction of leaves, it is also worth noting that the stems of Opuntia are modified into flattened green structures that perform photosynthesis. This adaptation allows the plant to continue to produce energy while minimizing water loss.

6. **Conclusion**: The adaptation of reducing leaves to spines in Opuntia is primarily to minimize water loss through transpiration, which is crucial for survival in a desert habitat.

7. **Final Answer**: The correct answer is that the adaptation of leaves being reduced to spines in Opuntia is to minimize water loss through transpiration.

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