Question

Rhodnius, a blood-sucking bug, shows five instars before it metamorphoses into an adult. It has a very long head with the brain located at its tip and an organ called Corpora Cardiaca (CC) behind it.The hormone that ensures the continuum of the juvenile stages is called a juvenile hormone. Behind the head is a pro-thoracic gland, which gets triggered by the Pro-Thoracico-Tropic Hormone $(PTTH)$ to release ecdysone required for molting into an adult.

The following observations were made when the juveniles of this insect were subjected to various conditions:
1. Starved juveniles (any instar) when decapitated remained juveniles and did not molt into adults.
2. Well-fed juveniles (any instar) when decapitated -» molted into adults.
3. Starved juveniles (any instar) when partially decapitated to remove the brain cells $\to$ remained juveniles and did not molt into adults.
4. Well-fed juveniles (any instar) when partially decapitated to remove the brain cells$\to$ did not molt into adults.
If an unfed, completely decapitated, fifth (final) instar juvenile is connected to a well-fed, decapitated fourth instar juvenile by a glass tube so that fluids can be exchanged, what will be the expected result?

• A. Both bugs will continue to remain juveniles
• B. Both bugs will molt into adult forms
• C. The bug in the fourth instar will remain as a juvenile while the one in the fifth instar will molt into an adult
• D. The bug in the fourth instar will molt into an adult and the one in the firth instar will remain as a juvenile

Answer 1

Answer: (B)

Correct answer is (b) Both bugs will molt into adult forms