Root cap is absent in

Options

A. Xerophytes
B. Mesophytes
C. Hydrophytes
D. Halophytes.

Answer

### Step-by-Step Solution:

1. **Understanding Root Cap**: The root cap is a protective structure at the tip of a plant root that helps in the growth of the root by protecting the delicate tissues behind it as it pushes through the soil.

2. **Analyzing the Options**:
- **Option 1: Xerophytes**: These are plants adapted to dry environments. They need to absorb and retain water efficiently, which means they must have a root cap to protect their growing roots. Therefore, root caps are present in xerophytes.
- **Option 2: Mesophytes**: These plants thrive in moderate environments with sufficient water. Like xerophytes, they also require root caps to help absorb water effectively. Thus, root caps are present in mesophytes as well.
- **Option 3: Hydrophytes**: These are aquatic plants that live in water. Since they are submerged in water, they do not need a root cap for protection against soil. Instead, many hydrophytes have adapted to have root pockets instead of root caps. Hence, root caps are absent in hydrophytes.
- **Option 4: Halophytes**: These plants are adapted to saline environments. Similar to xerophytes, they need root caps to help them absorb water and deal with salt stress. Therefore, root caps are present in halophytes.

3. **Conclusion**: Based on the analysis, the correct answer is that root caps are absent in **Option 3: Hydrophytes**.

### Final Answer:
Root cap is absent in **Hydrophytes**.

---