What characteristics do all living things share? A: They contain DNA
B: They are made up of many parts
C: They reproduce by mitosis
D: They need oxygen to survive

B because i said it was

Cell division is important to single celled organisms because it allows the cells to reproduce. through cell division, cells make exact copies of themselves. when single celled organisms go through cell division, they make exact copies of themselves which is how they reproduce.

Gay-lussac's law i think.