Which of the following is an isogamous plant, producing non-flagellated gametes ?

Options

A. Spirogyra
B. Volvox
C. Chlamydomonas
D. Fucus

Answer

To solve the question regarding which of the following is an isogamous plant producing non-flagellated gametes, we will analyze each option provided: Spirogyra, Volvox, Chlamydomonas, and Fucus.

### Step-by-Step Solution:

1. **Understanding Isogamy**:
- Isogamy refers to a type of sexual reproduction where the gametes are of similar size and shape. These gametes can be either flagellated or non-flagellated.

2. **Identifying the Options**:
- **Spirogyra**: This is a green alga that reproduces sexually through isogamy. The gametes produced by Spirogyra are non-flagellated and similar in size.
- **Volvox**: This organism reproduces sexually through oogamy, where the gametes are of different sizes (large non-motile eggs and small motile sperm).
- **Chlamydomonas**: This alga can exhibit both isogamous and anisogamous forms, but typically its gametes are flagellated.
- **Fucus**: This brown alga also reproduces through oogamy, with distinct male and female gametes.

3. **Conclusion**:
- Among the options, **Spirogyra** is the only plant that is isogamous and produces non-flagellated gametes.

Thus, the correct answer is **Spirogyra**.