Group of algae in which sexual reproduction is absent

Options

A. Bacillariophyceae
B. Cyanophyceae
C. Chlorophyceae
D. Phaeophyceae.

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks for a group of algae in which sexual reproduction is absent. We need to identify which of the given options does not engage in sexual reproduction.

2. **Defining Sexual Reproduction**: Sexual reproduction involves the fusion of gametes, resulting in the exchange of genetic material and the formation of progeny. This is a key characteristic that differentiates sexual reproduction from asexual reproduction.

3. **Analyzing the Options**: The options provided are:
- Bacillariophyceae (diatoms)
- Cyanophyceae (blue-green algae)
- Chlorophyceae (green algae)
- Phaeophyceae (brown algae)

4. **Identifying the Group Without Sexual Reproduction**:
- **Bacillariophyceae**: Sexual reproduction is present.
- **Cyanophyceae**: Sexual reproduction is absent. They reproduce asexually and produce motile unicellular forms called zoospores.
- **Chlorophyceae**: Sexual reproduction is present.
- **Phaeophyceae**: Sexual reproduction is present.

5. **Conclusion**: Based on the analysis, the group of algae in which sexual reproduction is absent is **Cyanophyceae**.

**Final Answer**: Cyanophyceae (blue-green algae) is the group of algae in which sexual reproduction is absent.

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