The pineal gland of some birds and reptiles is referred to as a primitive "third eye" because
A) it feeds light information to the eye.
B) the skull over the pineal gland is especially thin, so it can sense light.
C) it secretes the hormone melatonin, which is a metabolite of a hallucinogen.
D) it is the only unilateral structure in the brain.

Question

Quizplus · Accepted Answer

The skull over the pineal gland in some birds and reptiles is especially thin, allowing the gland to sense light and function as a primitive "third eye."

The Pineal Gland of Some Birds and Reptiles Is Referred