Isogamous sexual reproduction by involvement of non-motile gametes is found in `:`

Options

A. Spirogyra
B. Ulothrix
C. Chlamydomonas
D. Chara

Answer

To answer the question regarding isogamous sexual reproduction involving non-motile gametes, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Isogamy**:
- Isogamy refers to a type of sexual reproduction where the gametes involved are morphologically similar. This means that both male and female gametes look alike.

2. **Identify Non-Motile Gametes**:
- The question specifies that we are looking for isogamous reproduction that involves non-motile gametes. This means that both gametes do not have the ability to move independently.

3. **Evaluate the Options**:
- We need to analyze the given options (though not provided in the question, we can infer from the transcript) to find which organism exhibits isogamous reproduction with non-motile gametes.

4. **Examine Specific Organisms**:
- **Spirogyra**: In Spirogyra, while the gametes are morphologically similar (isogametes), one of the gametes shows motility during conjugation, so it does not fit the criteria.
- **Eulothrix**: Similar to Spirogyra, the gametes in Eulothrix are motile, which disqualifies it.
- **Chlamydomonas**: In Chlamydomonas, both gametes are flagellated and therefore motile, which again does not meet the requirement.

5. **Conclusion**:
- After evaluating the options, it appears that none of the mentioned organisms fit the criteria of having non-motile gametes in isogamous reproduction. However, if we consider organisms like **Certain species of algae**, which can have non-motile isogametes, they would be the correct answer.

### Final Answer:
The correct organism that exhibits isogamous sexual reproduction involving non-motile gametes is **Certain species of algae** (not specifically listed in the options).