What are 3 reasons why a cell may stop dividing at a checkpoint?

Cells divide for the purposes of reproduction, replacement of lost or dead cells and to promote growth of the structure in which they are located. Only the first of these reasons applies to single-celled organisms, but the others are essential to the efficient functioning of a multicellular body. Hope this helps

the dna of humans and mice is almost 92% similar. this similarity indicates that . mice have a tail, while humans have a tailbone. the tailbone is a structure in humans.yes it's true.