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

Answer

To solve the question, we need to analyze the pairs given in the options and determine which one is correct based on the anatomical differences between dicots and monocots, as well as their adaptations in hydrophytes.

### Step-by-Step Solution:

1. **Understanding Dicot Leaves:**
- Dicotyledonous plants have dorsoventral leaves.
- The upper surface is called the adaxial surface, and the lower surface is called the abaxial surface.
- In dicots, stomata are predominantly found on the abaxial surface (lower surface), making them hypostomatic leaves.

2. **Understanding Monocot Leaves:**
- Monocotyledonous plants have isobilateral leaves.
- In monocots, stomata are distributed equally on both the adaxial and abaxial surfaces.
- The term "epistomatic" (stomata on the upper surface) does not apply to monocots, as they have equal stomata on both surfaces.

3. **Analyzing Free-floating Hydrophytes:**
- Free-floating hydrophytes have leaves that are exposed to air on the upper surface while submerged on the lower surface.
- It is incorrect to say they have amphistomatic leaves since the lower surface is submerged in water and does not require stomata.

4. **Analyzing Submerged Hydrophytes:**
- Submerged hydrophytes have leaves that are fully underwater.
- Sunken stomata are a feature of xerophytes (plants adapted to dry conditions) to reduce water loss, not hydrophytes.

5. **Identifying the Correct Pair:**
- The only correct statement is that dicots have hypostomatic leaves, where stomata are mainly located on the abaxial surface.

Thus, the correct answer is the pair that states that in dicots, the stomata are more on the abaxial surface, confirming that they are hypostomatic.

### Final Answer:
The correct pair is: **Dicots - Hypostomatic leaves (more stomata on the abaxial surface).**

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