The basic unit of all forms of life is a(n)
a. organ system.
b. organ.
c. tissue.
d. cell. user: which of the following is an example of epithelial tissue?
a. bone
b. skin
c. fat
d. muscle user: the excretory system consists of which of the following organs?
a. stomach, liver, pancreas
b. lungs, nose, trachea
c. kidneys, ureters, urinary bladder
d. brain, spinal cord, sense organs