For the first question, I would say a line graph. And the one about the human heart, I need some more information.
<span>They indicate many forms of hominins spent considerable time in trees.</span>
The answer is D. 4 because its after perception
That's what is called competitive enzymatic regulation. If there are more of that substance than the enzyme substrate, then most of the enzyme, if not all depending on the substance's concentration, will be inhibited on its action. If there are more substrate then the competitive substance, the expected reaction for that enzyme will happen at an expected rate. If the ratio substrate:substance is 1:1 then the reaction enzyme-substrate is very slowed down.
For starters, humans have feelings and cells. If we get hurt we can feel things such as pain unlike a tent. If you hit a tent there is nothing it feels because it has no feelings. We have cells all through our body and rocks don't. They are made of other stuff but not cells.