During wall enlargement new wall materials are inserted amongst the older ones. The phenomenon is

Options

A. Accretion
B. Integration
C. Intussusception
D. Interpolation.

Answer

To solve the question regarding the phenomenon where new wall materials are inserted among older ones during wall enlargement, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Plant Cell Walls**:
- Plant cell walls are primarily composed of cellulose, which is a crucial component for providing structural support to the plant cells.

2. **Cell Division and Primary Cell Wall Formation**:
- During cell division, a structure called the cell plate forms, which eventually develops into the primary cell wall. This is the initial wall that surrounds the newly formed cell.

3. **Wall Enlargement Process**:
- After the cell has divided, the cell continues to grow. This growth involves the addition of new materials such as cellulose and pectin to the existing cell wall.

4. **Distinguishing Between Primary and Secondary Cell Walls**:
- The initial cell wall formed during division is known as the primary cell wall. As the cell enlarges, new materials are added to this wall, which leads to the formation of what is referred to as the secondary cell wall.

5. **Identifying the Correct Term**:
- The process of inserting new wall materials among the older ones is termed **intussusception**. This is distinct from other processes like accretion, which involves adding layers rather than inserting materials within existing layers.

6. **Conclusion**:
- Therefore, the phenomenon described in the question, where new wall materials are inserted among the older ones during wall enlargement, is known as **intussusception**.

### Final Answer:
The phenomenon is **intussusception**.

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