In cockroach, the juvenile hormone or neotinin is secreated by :

Options

A. Corpora cardiaca
B. Corpora allata
C. Prothoracic gland
D. Antennae

Answer

To answer the question "In cockroach, the juvenile hormone or neotenin is secreted by:", we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Context**: The juvenile hormone (also known as neotenin) plays a crucial role in the metamorphosis of cockroaches. It helps maintain larval characteristics during the nymphal stages.

**Hint**: Remember that juvenile hormone is involved in regulating the development stages of insects.

2. **Identify the Metamorphosis Type**: Cockroaches undergo hemimetabolism, which means they develop from eggs to nymphs and then to adults through several nymphal stages.

**Hint**: Recall the life cycle of cockroaches and the stages they go through.

3. **Locate the Source of the Hormone**: The juvenile hormone is secreted by a specific structure in the cockroach's body. In this case, it is important to identify which part of the cockroach's anatomy is responsible for this secretion.

**Hint**: Think about the brain structures involved in hormone secretion in insects.

4. **Evaluate the Options**:
- **Corpora Cardiaca**: This structure stores the prothoracic trophic hormone (PTTH) but does not secrete the juvenile hormone.
- **Corpora Elata**: This is the correct structure that secretes the juvenile hormone.
- **Prothoracic Gland**: This gland secretes ectodysone, not the juvenile hormone.
- **Antenna**: This structure does not secrete any hormones related to metamorphosis.

**Hint**: Compare the functions of each structure to determine which one is responsible for the secretion of the juvenile hormone.

5. **Conclusion**: Based on the evaluation of the options, the juvenile hormone or neotenin in cockroaches is secreted by the **Corpora Elata**.

**Final Answer**: In cockroach, the juvenile hormone or neotenin is secreted by **Corpora Elata**.