Which of the following statement about Spirogyra is correct?

Options

A. lateral conjugation takes place in homothallic species
B. scalariform conjugation takes place in homothallic species
C. lateral conjugation takes place in heterothallic species
D. the type of conjugation is unrelated to homothallic & heterothallic

Explanation

To determine the correct statement about Spirogyra, we need to analyze the information regarding its reproduction process, specifically focusing on the types of conjugation it undergoes.

### Step-by-Step Solution:

1. **Understanding Spirogyra**: Spirogyra is a genus of green algae known for its spiral chloroplasts and is commonly found in freshwater environments.

2. **Reproduction in Spirogyra**: Spirogyra reproduces both asexually and sexually. The sexual reproduction occurs through a process called conjugation.

3. **Types of Conjugation**:
- **Scleriform Conjugation**: This type occurs between heterothallic species of Spirogyra. Heterothallic species require two different mating types for conjugation.
- **Lateral Conjugation**: This occurs between adjacent cells of the same filament in homothallic species. Homothallic species can self-fertilize as they have both mating types.

4. **Subtypes of Lateral Conjugation**: Lateral conjugation can be further divided into:
- **Direct Lateral Conjugation**
- **Indirect Lateral Conjugation**

5. **Evaluating the Statements**:
- **Statement 1**: "Lateral conjugation takes place in homothallic species." - This is correct.
- **Statement 2**: "Scleriform conjugation takes place in homothallic species." - This is incorrect; it occurs in heterothallic species.
- **Statement 3**: "Lateral conjugation takes place in heterothallic species." - This is incorrect; it occurs in homothallic species.
- **Statement 4**: "The type of conjugation is unrelated to the homothallic and heterothallic." - This is incorrect; the type of conjugation is indeed related to whether the species is homothallic or heterothallic.

6. **Conclusion**: The only correct statement is that lateral conjugation takes place in homothallic species.

### Final Answer:
The correct statement about Spirogyra is: **Lateral conjugation takes place in homothallic species.**