Question

In snakes, eyelids are:
A. Immovable
B. Movable
C. Absent
D. All of these

Answer 1

Hint: Eyelids are thin membranous layers of skin that cover the eyes and protect it. Humans have both- upper and lower eyelids. Not all animals have such a structure.

Complete Step by Step Answer:
Snakes, belonging to the class- Reptilia, have eyes with two cones. They can see only two primary colours: blue and green. Therefore, they are called dichromatic. They, unlike human beings, do not have eyelids. Instead they have what is known to be called brille. Brille is a translucent/transparent membrane. This is usually immovable. It is said to be the fusion of the upper and lower eyelids.

It is believed that snakes do not have eyelids so that it does not become a hindrance while shedding off the skin.

Thus, the correct answer is C: Absent.

Additional information Snakes are called reptiles because they have a bony skeleton and their outer surface of body is covered with scales. They have no limbs but a long slender body. with scales and lay hard shelled eggs. Snakes also don't have external ears. Small snakes have one lung while larger snakes like cobras have two lungs.

Note: Nocturnal snakes have slits in their eyes while other snakes have round eyes. Some reptiles are known to have a third eyelid called the nictitating membrane. It extended from the medial canthus( inner corner of eye) to lateral canthus(exterior corner of the eye). This helps in providing moisture to their eyes.