Fact 1: Cells are the basic units of the structure and function of living things.

Fact 2: Humans, angels, animals, and all other living things are finite.

Given the two facts above, answer the question "what are cells the basic units of?" with the following options: 
- density
 - clouds
 - embryos
 - plants
 - matter
 - ferns
 - humans
 - batteries


 

       humans  