Vegetatively the members of cyanophyceae multiply by

Options

A. akinetes
B. fragmentation
C. formation of horomogonia
D. all of the above

Answer

To answer the question "Vegetatively the members of Cyanophyceae multiply by," we need to explore the various methods of vegetative reproduction in Cyanophyceae, commonly known as blue-green algae.

### Step-by-Step Solution:

1. **Understanding Cyanophyceae**:
- Cyanophyceae, or blue-green algae, are prokaryotic organisms that can perform photosynthesis. They are often found in aquatic environments and can sometimes lead to water contamination.

2. **Vegetative Reproduction**:
- Vegetative reproduction is a form of asexual reproduction where new individuals are produced without the involvement of gametes. In Cyanophyceae, this process can occur through several methods.

3. **Methods of Vegetative Reproduction**:
- **Fragmentation**: This is a process where the parent organism breaks into fragments, and each fragment can grow into a new individual. In Cyanophyceae, this occurs when the filamentous structures break apart.
- **Formation of Hormogonia**: Hormogonia are short, motile fragments formed by the fragmentation of filaments (trichomes). These fragments can grow into new individuals.
- **Formation of Akinites**: Akinites are specialized dormant cells that develop under unfavorable conditions. They are larger vegetative cells with thick walls that help them resist environmental stress.

4. **Conclusion**:
- All the methods mentioned (fragmentation, formation of Hormogonia, and formation of Akinites) are ways in which members of Cyanophyceae multiply vegetatively. Therefore, the correct answer to the question is "all of the above."

### Final Answer:
Vegetatively, the members of Cyanophyceae multiply by **all of the above** methods: fragmentation, formation of Hormogonia, and formation of Akinites.

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