Suppose you lean against a wall. You are pushing on the wall, but is the wall pushing back? How do you know?

yes the wall is pushing back.

Explanation:

This means that when you push on a wall, the wall pushes back on you with a force equal in strength to the force you exerted.

Explanation:

Third law of motion because there's an equal and opposite reaction from you to the wall.

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

a- all cells come from pre-existing cells