Filling of contractile vacuole and its swelling is called

Options

A. Diastole
B. Diapause
C. Systotle
D. Both A and B

Answer

To answer the question regarding the filling and swelling of the contractile vacuole, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Understanding Contractile Vacuoles**:
- Contractile vacuoles are specialized organelles found in certain protozoans. They play a crucial role in osmoregulation, helping to maintain the balance of water within the cell.

2. **Function of Contractile Vacuoles**:
- These vacuoles collect excess water that enters the cell. If too much water accumulates, it can lead to cell rupture. Therefore, the contractile vacuole helps to expel this excess water.

3. **Process of Filling and Swelling**:
- When water enters the contractile vacuole, it causes the vacuole to swell. This process of filling and swelling is specifically referred to as "diastole."

4. **Understanding the Terms**:
- The term "diastole" refers to the phase when the vacuole is filling with water and expanding.
- Conversely, when the vacuole contracts to expel the water, this phase is known as "systole."

5. **Identifying the Correct Answer**:
- Based on the definitions and functions discussed, the correct answer to the question about the filling and swelling of the contractile vacuole is **option A: Diastole**.

### Final Answer:
The filling of the contractile vacuole and its swelling is called **diastole**.

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