Question

Rhodinus, 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 remained juveniles and did not molt into adults.
4. Well-fed juveniles (any instar) when partially decapitated to remove the brain cells did not molt into adults.
what conclusions be drawn from these data?.
i. Ecdysone hormone is produced irrespective of the level of feeding.
ii. CC is the site of production of juvenile hormone.
iii. PTTH is produced irrespective of the level of feeding.
iv. Increase in juvenile hormone is an important trigger for production of PTTH.
v. Absence of CC alone is a trigger for molting into adult form.
vi. Well-fed larvae in absence of juvenile hormone can molt into adults

options:
(a) i,iii,iv and v
(b) ii,iv and v
(c) ii and vi
(d) i and iv

Answer 1

Answer:

hey mate ✌✌

➡️ here , from the above statements, statements 1,3,6,are not following the above statements

➡️ since, the statement 2,4,5 are following the above situations.

we can easily conclude that option (b) I.e, 2,4 and 5 is the correct answer.

Explanation:

hope it helps ✔

Answer with quality ✔✔