Vegetative reproduction by fragmentation is common in

Options

A. Agaricus
B. Saccharomyces
C. Euglena
D. Gonyaulax

Answer

To answer the question about which organism commonly reproduces vegetatively by fragmentation, we can analyze the options provided: Agaricus, Saccharomyces, Euglena, and Gonolax.

### Step-by-Step Solution:

1. **Understanding Vegetative Reproduction**:
- Vegetative reproduction is a form of asexual reproduction where new individuals are produced from the vegetative parts of the parent organism. This process does not involve seeds or spores.

2. **Defining Fragmentation**:
- Fragmentation is a specific type of vegetative reproduction where the organism breaks into fragments, and each fragment can grow into a new individual. This is commonly seen in filamentous organisms.

3. **Analyzing Each Option**:
- **Agaricus**: This is a genus of mushrooms. Agaricus can reproduce through fragmentation, where parts of the mycelium can break off and develop into new fungal bodies.
- **Saccharomyces**: This is yeast, which primarily reproduces by budding and does not typically undergo fragmentation.
- **Euglena**: This is a protozoan that reproduces mainly by binary fission, not by fragmentation.
- **Gonolax**: This organism also reproduces by binary fission and does not utilize fragmentation.

4. **Conclusion**:
- Based on the analysis, the organism that commonly reproduces vegetatively by fragmentation is **Agaricus**.

### Final Answer:
**Agaricus** is the organism that commonly reproduces vegetatively by fragmentation.