Based on fossil evidence, about how long ago did the first single celled life fork appear on earth?

In "the man in the water," what was the remarkable occurrence that rosenblatt reported?

In order to study genetic mutations, scientists must study genetic material. which statement describes the genetic material scientists are most likely studying? a) they study alleles that contain chromosomes, which are rna.b) they study alleles that contain genes, which are chromosomes.c) they study chromosomes that contain genes, which are dna segments.

Which organ controls breathing? lungs alveoli heart diaphragm