Ok here we go:
Science starts with observing which leads to hypothesis, which is tested by experiments.
The other two i am not sure of. Hope i was a help to you. One thing you can do to figure out the other two is google: "what type of science includes medicine and envirnmental science", and do the same for the other one.
Mitosis is when the cell divides
The answer to ur question is A
Clues such as fossils such as bones, footprints, tar, etc, preserved underground helped inform scientists. You can also count how old a tree is when you cut it open and there are some alive for thousands of years so that is a possible way.