Root cambium is

Options

A. Primary meristem
B. Secondary meristem
C. Intercalary meristem
D. Apical meristem

Answer

To determine what root cambium is, we will analyze the options provided in the question step by step.

### Step 1: Understand the Types of Meristems
Meristems are regions in plants where cells continuously divide and contribute to growth. There are different types of meristems:
- **Primary Meristem**: Responsible for the primary growth of the plant, leading to an increase in length.
- **Secondary Meristem**: Responsible for secondary growth, which increases the thickness of the plant.
- **Intercalary Meristem**: Found at the base of leaves or internodes, contributing to growth in these specific areas.
- **Apical Meristem**: Located at the tips of roots and shoots, responsible for the elongation of these parts.

### Step 2: Analyze the Root Cambium
Root cambium is a type of meristematic tissue found in the roots of vascular plants. It is specifically involved in secondary growth, which means it contributes to the increase in the girth of the root.

### Step 3: Identify the Correct Option
From the analysis:
- **Option 1 (Primary Meristem)**: Incorrect, as root cambium is not involved in primary growth.
- **Option 2 (Secondary Meristem)**: Correct, as root cambium is involved in secondary growth.
- **Option 3 (Intercalary Meristem)**: Incorrect, as it is not responsible for the growth of nodes and internodes.
- **Option 4 (Apical Meristem)**: Incorrect, as it is located at the tips of roots and stems.

### Conclusion
The correct answer is **Option 2: Secondary Meristem**. Root cambium is a type of secondary meristem that contributes to the secondary growth of roots.

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