Question

Harderian gland occurs in
A. Lizard
B. Frog
C. Birds
D. All of the above

Answer 1

Hint: Harderian glands are present in the orbit of eyes. Some animals have a nictitating membrane in their eye having the harderian gland. The secretions of the harderian gland help in providing lubrication to the eye.

Complete answer: Harderian glands are the pigmented tear or lacrimal glands present in the eye’s orbit. These glands are present in the tetrapods like amphibians, reptiles, aves, and mammals. Harderian glands act as the secretory glands as they secrete porphyrin rich material and lipids. These secretions help in lubricating eyes as well as eyelids.
a) Lizard:
Lizards belong to the order Squamata of the subclass Diapsida of the class Amphibia. The Amphibia is a subclass of the superclass Tetrapoda. Tetrapoda consists of animals that have two pairs of limbs. Tetrapods have a nictitating membrane in their eye that has the Harderian gland. Lizards also have a nictitating membrane and the harderian glands are present.
Frog:
b) Frog belongs to the order Anura of the class Amphibia. The Amphibia is a subclass of the superclass Tetrapoda. Tetrapoda consists of animals that have two pairs of limbs. Tetrapods have a nictitating membrane in their eye that has the Harderian gland. Frogs also have the nictitating membrane and the harderian glands are present.
c) Birds:
Birds are members of the class Aves. Aves is a subclass of the superclass Tetrapoda. Tetrapoda consists of animals that have two pairs of limbs. Tetrapods have a nictitating membrane in their eye that has the harderian gland. Thus, based on the above information we can conclude that the Harderian gland occurs in lizards, frogs, and birds.
Hence, the correct answer is option D.

Note: The nictitating membrane is a kind of translucent or transparent membrane. It acts as the third eyelid in some animals because it draws perpendicular to the movement of the eyelids. The nictitating membrane helps in protecting the eyes from dust, rain, snow, etc. It also allows animals to have a clear vision under the water.