Histogen found at the tip of root apical meristem is

Options

A. plerome
B. periblem
C. calyptrogen
D. Dermatogen

Answer

To answer the question regarding the histogen found at the tip of the root apical meristem, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Histogens**: Histogens are groups of cells in the meristematic region that give rise to different tissues in plants. In the context of root apical meristem, there are specific histogens that contribute to the formation of various root tissues.

2. **Identify the Types of Histogens**: The main histogens associated with the root apical meristem are:
- **Dermatogen**: The outermost layer that forms the epidermis.
- **Periblem**: The middle layer that develops into the cortex and other ground tissues.
- **Plerome**: The innermost layer that gives rise to vascular tissues (xylem and phloem).
- **Caliptrogen**: A specialized meristematic tissue that forms the root cap.

3. **Focus on the Root Apical Meristem**: The root apical meristem is responsible for the growth of roots. It consists of these histogens, and each has a specific role in root development.

4. **Determine the Histogen at the Tip**: The question specifically asks for the histogen found at the tip of the root apical meristem. The tip of the root is primarily associated with the formation of the root cap for protection.

5. **Conclude with the Correct Answer**: Based on the information gathered, the histogen found at the tip of the root apical meristem is **Caliptrogen**. It is responsible for forming the protective root cap.

### Final Answer:
The histogen found at the tip of the root apical meristem is **Caliptrogen**.