Well in order for chemical digestion to occur period, a enzyme is needed.
In the mouth this enzyme is amylase
Answer:
The return of blood to the heart is assisted by the action of the skeletal- muscle pump. As muscles move, they squeeze the veins running through them. Veins contain a series of one-way valves, and they are squeezed, blood is pushed through the valves, which then close to prevent backflow.
Answer:
Explanation:
it really depends on the animal but its blinking
A genetic mutation is a permanent modification in the DNA sequence of a gene to what is found in most people.
