Question

Nictitating membrane is vestigial in

• A. Frog
• B. Rabbit
• C. Human
• D. All the above

Answer 1

The correct option is C Human

The plica semilunar is an overlay of conjunctiva at the internal corner of the human eye. Its similarity to the nictitating membrane or third eyelid, of different creatures prompted the possibility that it may be the remnant of such a structure, which is still the piece of the eye in a few primates, including gorillas. The capacity of the nictitating layer in numerous creatures is defensive for instance, keeping the eye spotless and sodden or disguising the iris from predators. In a few animal groups, the layer is adequately straightforward in order to empower vision when underground or submerged. In spite of the fact that the explanation behind the passing of a nictitating layer in people in hazy, changes in territory and eye physiology may have rendered the tissue superfluous.

So, the correct option is 'Human'.