Question

The human body has four types of tissues. What part of the eye uses muscle tissue for opening and closing movements?

a. Iris
b. Sclera
c. Cornea
d. Retina

Answer 1

The iris

Step-by-step explanation:

The iris contains muscles that allow the pupil to become larger (open up or dilate) and smaller (close up or constrict). The iris regulates the amount of light that enters your eye by adjusting the size of the pupil opening.

Answer 2

The iris

Step-by-step explanation:

The sphincter muscle of the iris is a circular muscle that constricts the pupil in bright light, whereas the dilator muscle of the iris expands the opening when it contracts.