Name an organelle that you see in the plant cell that you did not see in the animal cell

What substance acts to prevent sudden ph changes in bodily fluids?

This is a biological reaction due to a stimulus. i need this quickly !

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