Which of the following is multicellular filamentary?

Options

A. Spirogyra
B. Chlamydomonas
C. Volvox
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for an organism that is multicellular and filamentary. This means we need to identify an organism that is made up of multiple cells and has a filament-like structure.

2. **Analyzing the Options**: The options given are likely to include various types of algae. We need to evaluate each option based on their cellular structure and form.

3. **Evaluating Spirogyra**:
- Spirogyra is known as "Pond Silk" because it forms long, green filaments that can cover the surface of ponds.
- It is composed of multiple cells arranged in a filamentous structure.
- Spirogyra is classified as an algae and is indeed multicellular.

4. **Evaluating Other Options**:
- **Clamydomonas**: This is a unicellular green algae, and it does not have a filamentous structure.
- **Volvox**: This is a colonial green algae, but it is not filamentous in structure; it forms spherical colonies.
- **Others (if any)**: If there are any other options, they should be evaluated similarly, but based on the information given, they do not fit the criteria of being multicellular and filamentous.

5. **Conclusion**: Based on the analysis, Spirogyra is the only organism among the options that is multicellular and filamentary. Therefore, it is the correct answer.

**Final Answer**: Spirogyra

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