Eutely is exhibited by

Options

A. Flatworms
B. roundworms
C. tapeworms
D. acornworms

Answer

### Step-by-Step Solution:

1. **Understanding Eutely**:
- Eutely is a biological condition where an organism has a constant number of cells throughout its life cycle. This means that the total number of cells does not change after a certain stage of development.

2. **Identifying Organisms that Exhibit Eutely**:
- Eutely is primarily observed in certain groups of organisms, particularly in the phylum Nematoda, which includes roundworms.

3. **Characteristics of Eutely**:
- In organisms exhibiting eutely, after reaching maturity, the process of cell division ceases. Instead, the existing cells may undergo elongation or growth, but no new cells are formed.

4. **Examples of Organisms**:
- The most notable examples of organisms that exhibit eutely are the roundworms (Nematodes). Other groups, such as flatworms, do not exhibit eutely because they can regenerate and continue cell division throughout their life.

5. **Conclusion**:
- Therefore, the organisms that exhibit eutely are primarily found in the phylum Nematoda, specifically the roundworms.

### Final Answer:
Eutely is exhibited by roundworms (phylum Nematoda).

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