Organisms And Population Question 108
Question: Read the assertion and reason carefully to mark the correct option out of the options given below:
Assertion : Nerve supply to a cut part is essential for initiation and completion of regeneration. Reason : Nerve secretes epidermal growth factor and neurotrophic factor for regeneration.
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If both the assertion and reason are false
Show Answer
Answer:
Correct Answer: D
Solution:
Regeneration has been shown that if a limb is first denervated and then amputated, or if nerves are by any means blocked from penetrating the epidermis, no regenerative blastema is formed.
But if the amputated limb is denervated after the initiation of blastema formation, regenerative process continues and new limb is formed.
This confirmed that nerve supply is required for the initiation of regeneration but not for its completion.
The epithelium stimulates the secretion of certain proteinous growth factor like epidermal growth factor (EGF).
EGF stimulates the mitotic division and neurons secrete some trophic factor which are essential for the regeneration of amphibian limb.
BETA
