Question

The hormone responsible for the growth and moulting of insects is secreted by:

• A. Corpora allata
• B. Corpora cardiaca
• C. Neurosecretory brain cell
• D. Salivary gland

Hint:

Insect hormones:
- Corpora allata: Juvenile hormone (growth, moulting).
- Corpora cardiaca: PTTH (stimulates moulting).
- Prothoracic gland: Ecdysone (moulting hormone).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
This question tests knowledge of insect endocrine system and hormone secretion.

Step 2: Detailed Explanation:
The corpora allata secretes juvenile hormone (JH), which is responsible for growth, development, and moulting.
Corpora cardiaca (B): Secretes prothoracicotropic hormone (PTTH).
Neurosecretory brain cells (C): Produce PTTH, which stimulates the prothoracic gland.
Salivary gland (D): Not a hormone-secreting organ.
Thus, the corpora allata secretes the hormone responsible for growth and moulting.

Step 3: Final Answer:
Thus, the hormone responsible for growth and moulting is secreted by the corpora allata, which corresponds to option (A).
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