Entamoeba differs from Amoeba is not having

Options

A. Nucleus
B. Pseudopodia
C. Ectoplasm
D. Contractile vacuole

Answer

To solve the question "Entamoeba differs from Amoeba in not having," we will analyze the options provided and determine which structure is absent in Entamoeba.

### Step-by-Step Solution:

1. **Understanding the Organisms**:
- Both Entamoeba and Amoeba are protozoans. They belong to the same family but have different characteristics.

2. **Analyzing the Options**:
- **Option 1: Nucleus**:
- Both Entamoeba and Amoeba possess a nucleus. Therefore, this option is not correct.

- **Option 2: Pseudopodia**:
- Both organisms have pseudopodia, which are extensions of the cell membrane used for movement and capturing food. Thus, this option is also not correct.

- **Option 3: Ectoplasm**:
- Ectoplasm is the outer layer of the cytoplasm and is involved in the formation of pseudopodia. Since both organisms have ectoplasm, this option is not correct either.

- **Option 4: Contractile Vacuole**:
- The contractile vacuole is responsible for regulating water balance in the cell. Amoeba requires a contractile vacuole to maintain osmotic balance, especially in freshwater environments. However, Entamoeba typically lives in isotonic environments (like the human intestine) where the osmotic pressure is balanced, so it does not need a contractile vacuole.

3. **Conclusion**:
- Since Entamoeba does not have a contractile vacuole, the correct answer is **Option D: Contractile Vacuole**.

### Final Answer:
**Entamoeba differs from Amoeba in not having a contractile vacuole.**

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