Name an organism which has no definite shape , and it keeps on changing its shape .

Options

A. Amoeba
B. Pitcher plant
C. Rabbit
D. Mouse

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for an organism that does not have a definite shape and can change its shape continuously.

2. **Identifying Organism Types**: We need to consider different types of organisms. The options provided include amoeba, rabbit, pitcher plant, and mouse.

3. **Analyzing the Options**:
- **Rabbit**: This is a multicellular organism with a definite shape.
- **Pitcher Plant**: This is also a multicellular organism with a fixed structure.
- **Mouse**: Like the rabbit, this is a multicellular organism that has a specific shape.
- **Amoeba**: This is a unicellular organism known for its ability to change shape.

4. **Focusing on Amoeba**: Amoeba is a protozoan that does not have a fixed shape. It can change its form by extending and retracting its pseudopodia (false feet), which allows it to move and engulf food.

5. **Conclusion**: The organism that has no definite shape and keeps changing its shape is **Amoeba**.

**Final Answer**: Amoeba

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