Which of the following unicellular organisms moves about in the same manner as a Chlamydomonas?

Options

A.
B.
C.
D.

Explanation

To determine which unicellular organism moves about in the same manner as *Chlamydomonas*, we need to analyze the movement mechanisms of the given organisms.

### Step-by-Step Solution:

1. **Identify the Movement of *Chlamydomonas***:
- *Chlamydomonas* is a unicellular green alga that moves using two whip-like structures called flagella. These flagella beat in a coordinated manner, allowing the organism to swim through water.

2. **List the Organisms**:
- The organisms given in the question are:
- Hydra
- Euglena
- Paramecium
- Amoeba

3. **Analyze Each Organism**:
- **Hydra**: This is a multicellular organism that moves using tentacles. It does not have flagella, so it does not move like *Chlamydomonas*.
- **Euglena**: This is a unicellular organism that also has flagella. It moves using its flagellum, similar to *Chlamydomonas*.
- **Paramecium**: This organism moves using cilia, which are short hair-like structures covering its surface. This is different from the flagella of *Chlamydomonas*.
- **Amoeba**: This organism moves using pseudopodia (false feet). It extends its cell membrane to move, which is also different from the flagella.

4. **Conclusion**:
- The only organism that moves in the same manner as *Chlamydomonas* (using flagella) is **Euglena**.

### Final Answer:
The unicellular organism that moves about in the same manner as *Chlamydomonas* is **Euglena**.