________ The heart is about the size of a fist and weighs approximately 9 ounces.
Indicate whether the statement is true or false
Question 2
There are many types of sensory receptors, starting from the very simple nerves that receive pain to very complex receptors, including those in the ______ of the eye, which collects all the input necessary for sight.
a. retina
b. iris
c. pupil
d. lashes