Assertion : Cells vary greatly in their shape.
Reason : The shape of cell does not depend on the function they perform.

Options

A. If both assertion and reason are true amnd reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "Cells vary greatly in their shape." This is a true statement. Cells come in various shapes and sizes, which can be observed in different types of cells such as bacteria, red blood cells (RBCs), nerve cells, etc.

2. **Understanding the Reason**: The reason states that "The shape of the cell does not depend on the function they perform." This statement is false. The shape of a cell is often closely related to its function. For example, the biconcave shape of red blood cells allows them to efficiently carry oxygen and navigate through narrow capillaries.

3. **Examples of Cell Shapes and Their Functions**:
- **Red Blood Cells (RBCs)**: They are biconcave in shape, which increases their surface area for oxygen transport and allows them to move easily through capillaries.
- **Nerve Cells**: They have a long and branched structure, which is essential for transmitting signals over long distances.
- **Bacteria**: They can have various shapes such as spherical (cocci), rod-shaped (bacilli), or spiral (spirilla), which can affect their mobility and how they interact with their environment.

4. **Conclusion**: Since the assertion is true and the reason is false, we conclude that the assertion is correct, but the reason does not support it. Therefore, the correct answer is that the assertion is true, but the reason is false.

### Final Answer:
- **Assertion**: True
- **Reason**: False

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