The smallest independently functioning unit of an organism is a(n) ________.
a. cell
b. molecule
c. organ
d. tissue
A collection of similar tissues that performs a specific function is an ________.
a. organ
b. organelle
c. organism
d. organ system
The body system responsible for structural support and movement is the ________.
a. cardiovascular system
b. endocrine system
c. muscular system
d. skeletal system