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Assertion : Bursa fabricii liles on the ...

Assertion : Bursa fabricii liles on the ventral side of the cloace in birds.
Reason : Bursa fabricii is related with flight adaptation.

A

If both assertion and reason are true and reason is the correct explanation of assertion

B

If both assertion and reason are true but reason is not the correct explanation of assertion

C

If assertion is true but reason is false

D

If both assertion and reason are false.

Text Solution

Verified by Experts

The correct Answer is:
D
A small, glandular, blind pouch of lymphatic tissue, the bursa lies on the dorsal side of the cloaca. It is lined with endoderm, and opens into the proctodaeum. In a young bird, bursa fabricii forms lymphocytes, and probably it produces antibodies and protects against local infection, but it atrophies in the adult before sexual maturity. It is also called cloacal thymus, because like thymus, it secretes lymphocytea. Thus it is not related with flight adaptation, rather it helps in immunity.
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