The food that is undigested and fails to break down becomes stool because it can not be used.
The part of the eye that prevent light from reflecting internally and is heavily vascularized to deliver blood to the retina: choroid.
<h3>What is choroid?</h3>
The choroid is highly vascularized to provide blood to the retina and contains dark pigmentation to stop light from reflecting inside. Anteriorly, the choroid, ciliary body, and iris are all joined.. The ciliary body muscles regulate the lens's thickness. The iris acts as a diaphragm, changing the pupil's aperture at its center. This regulates how much light is allowed to enter the retina. In strong light, the iris' muscle fibers constrict the pupil to accommodate close vision; in low light, they enlarge it to accommodate far vision. Each individual's iris is a different color.
To know more about choroid visit:
brainly.com/question/799280
#SPJ4
Answer:
D.Long necks were a random genetic change and resulted in the gradual increase of organisms with long necks.
Explanation:
