At some places, the cambium forms a narrow bands of (A)____ which passes throught he secondary xylem and the secondary phloem in the radial directions. These are the (B)_____

Answer

To solve the question, we need to identify what (A) and (B) represent in the context of cambium activity in plants, specifically regarding secondary growth.

### Step-by-Step Solution:

1. **Understanding Cambium and Its Role**:
- Cambium is a layer of tissue in plants that is responsible for secondary growth. It is a type of meristematic tissue that produces secondary xylem (wood) and secondary phloem (bark).

**Hint**: Recall what cambium does in plants and how it contributes to growth.

2. **Identifying the Structure Formed by Cambium**:
- The question states that cambium forms a narrow band that passes through the secondary xylem and secondary phloem in a radial direction. This band is composed of parenchyma cells.

**Hint**: Think about the types of cells that are typically involved in the secondary growth process.

3. **Naming the Narrow Band**:
- The narrow band of parenchyma cells formed by the cambium is known as "parenchyma" (A).

**Hint**: Consider the characteristics of parenchyma cells and their role in the plant structure.

4. **Understanding the Result of Cambium Activity**:
- When this narrow band of parenchyma cells invades the space between vascular bundles, it forms structures known as "secondary medullary rays" (B). These rays help in the lateral transport of nutrients and water.

**Hint**: Reflect on how the arrangement of vascular tissues contributes to the overall structure and function of the plant.

5. **Final Answer**:
- Therefore, (A) is "parenchyma" and (B) is "secondary medullary rays".

### Summary:
- (A) = Parenchyma
- (B) = Secondary Medullary Rays