The main three theories are that - all organisms are composed of cells- the cell is the basic unit of structure and organization in organisms- All cells come from pre-existing cells
If the arteries become less stretchy, the heart will have to work harder to eject blood.
Answer:
It's controlled by the nervous system and would be the effector
Explanation:
Not sure if that's what the question is asking but there you go
Probably D because ignoring them will make them want to talk more
