Select the correct pair out of the following

Options

A. Hypostomatic leaf-dicots
B. epistomatic leaf-monocots
C. amphistomatic leaf-free-floating hydrophytes
D. presence of sunken stomata in leaf-submerged hydrophytes

Explanation

To solve the question of selecting the correct pair regarding stomata in different types of leaves, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Stomata**:
- Stomata are small openings on the leaf surface that facilitate gas exchange. They are surrounded by guard cells that control their opening and closing.

2. **Identifying Types of Stomata**:
- **Epistomatic**: Stomata located on the upper surface of the leaf. This condition is commonly found in hydrophytes (plants that live in water).
- **Hypostomatic**: Stomata located on the lower surface of the leaf. This condition is typically found in dicotyledonous plants (dicots).
- **Amphistomatic**: Stomata present on both the upper and lower surfaces of the leaf. This condition can be found in some plants, including certain monocots.
- **Sunken Stomata**: These are stomata that are recessed below the leaf surface, which helps reduce water loss. This adaptation is usually found in xerophytic plants (plants adapted to dry environments).

3. **Analyzing Each Option**:
- **Option A**: Hypostomatic leaf - Dicot: This is correct. Dicot leaves typically have stomata on the lower surface.
- **Option B**: Epistomatic leaf - Monocot: This is incorrect. Monocots typically have amphistomatic leaves.
- **Option C**: Amphistomatic leaf - Hydrophytes: This is incorrect. Hydrophytes usually have epistomatic leaves.
- **Option D**: Presence of sunken stomata - Leaves submerged hydrophytes: This is incorrect. Sunken stomata are characteristic of xerophytic plants, not submerged hydrophytes.

4. **Conclusion**:
- The only correct pair is **Option A: Hypostomatic leaf - Dicot**.

### Final Answer:
The correct pair is **A: Hypostomatic leaf - Dicot**.

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