Home
Class 12
BIOLOGY
Assertion : Cornea is considered as an i...

Assertion : Cornea is considered as an immunologically privileged site.
Reason : A transplanted cornea is rarely rejected.

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:
A
Some transplanted tissues do not stimulate an immune response. For example, a transplanted cornea is rarely rejected because lymphocytes do not circulate into the anterior chamber of the eye, that’s why this site is considered as immunologically privileged site.
Promotional Banner

Similar Questions

Explore conceptually related problems

Assertion : Monera are considered as ancestral to bacteria and blue-green algae . Reason : Monera are the primitive cells contained clumps of nucleoproteins embedded in cell membrane.

Assertion : An organ transplant patient if not provided with cyclosporin A may reject the transplanted organ. Reason : Cycosporin A inhibits activation of T-cells and interferes with destruction of non-self cells.

Assertion (A) : Burning of a candle is considered a physical as well as chemical change. Reason (R) : Melting of wax is a physical change melted wax turns into vapours and then burns which is a chemical change.

Assertion:(A): Paratope is the antigen -binding site Reason(R ): It is a part of antibody

Assertion : Small sized animals are rarely found in polar regions. Reason : Small sized animals have larger surface area relative to their volume and they have to spend much energy to generate body heat through metabolism.

Assertion (A) : Pteridophytes considered as first true land plants. Reason (R ) : Pteridophytes were the first plant to acquire vascular tissue hence called vascular cryptogams.

Assertion: The portion of the myofibril between two successive Z-lines is considered as the functional unit of contraction called sarcomere. Reason: During contraction, l-bands get reduced whereas A-bands retain the length , thereby causing shortening of the sarcomere.

Cornea trasplant in human is almost never rejected state the reason.