Ecdysone is secreted in

Options

A. Nematoda
B. Polychaeta
C. Trematoda
D. Insecta.

Answer

**Step-by-Step Solution:**

1. **Understanding Ecdysone**: Ecdysone is a hormone known as the molting hormone. It plays a crucial role in the process of ecdysis, which is the shedding of the outer exoskeleton in arthropods.

2. **Identifying the Source**: Ecdysone is primarily secreted by the prothoracic glands in insects. This hormone is essential for the growth and development of insects as they transition from nymphs to adults.

3. **Analyzing the Options**: The question provides several options to identify where ecdysone is secreted:
- **Nematoda**: This phylum includes roundworms, which do not undergo molting in the same way as arthropods.
- **Polychaeta**: This class of annelids does not exhibit ecdysis like insects.
- **Trematoda**: This class includes flukes, which also do not undergo molting.
- **Cockroach**: As a member of the class Insecta, cockroaches undergo ecdysis and secrete ecdysone.

4. **Conclusion**: Based on the analysis, the correct answer is that ecdysone is secreted in **cockroaches** (option 4).

5. **Final Answer**: Therefore, the answer to the question is that ecdysone is secreted in **cockroaches**.

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