Which of following boundary is capable of growth, which gradually diminishes as the cell matures?

Options

A. Primary cell wall
B. Secondary cell wall
C. Tertiary cell wall
D. Cell membrane

Answer

To answer the question "Which of the following boundary is capable of growth, which gradually diminishes as the cell matures?", we will analyze the options provided and determine which boundary fits the criteria.

### Step-by-Step Solution:

1. **Identify the Options**: The question presents several boundaries to consider, including the primary cell wall, secondary cell wall, tertiary cell wall, and cell membrane.

2. **Analyze the Primary Cell Wall**:
- The primary cell wall is a thin and flexible layer.
- It is capable of growth, which means it can expand as the cell grows.
- The composition of the primary cell wall includes approximately 25% cellulose, 25% hemicellulose, 35% pectins, and 8% structural proteins. As these components increase, the ability of the primary cell wall to grow is enhanced.

3. **Evaluate the Secondary Cell Wall**:
- The secondary cell wall forms after the primary cell wall and is thicker and more rigid.
- It primarily consists of cellulose (around 45%) and may contain lignin, but it does not grow in the same way as the primary cell wall. Instead, it provides structural support and does not expand as the cell matures.

4. **Consider the Tertiary Cell Wall**:
- The tertiary cell wall is often made of several layers and is typically found in specific types of plant cells.
- It is not primarily responsible for growth and does not fit the criteria of a boundary that diminishes as the cell matures.

5. **Examine the Cell Membrane**:
- The cell membrane (or plasma membrane) surrounds all cells and separates the interior of the cell from the external environment.
- However, the cell membrane is not capable of growth in the same sense as the primary cell wall. It maintains its structure and does not expand as the cell matures.

6. **Conclusion**:
- Based on the analysis, the primary cell wall is the only boundary that is capable of growth and gradually diminishes in its ability to grow as the cell matures. Therefore, the correct answer is the **primary cell wall**.

### Final Answer:
**The primary cell wall is the boundary capable of growth, which gradually diminishes as the cell matures.**