All of the cell theory? (4 points) Oa
Every living thing is composed of cells.
Ob
c
Cells come from pre-existing cells.
Cells are the basic unit and structure of all living things.
Od
Every cell has a nucleus that contains genetic material.

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems