How did scientists form the geologic time scale?
how is this scale organized?
what processes changed earth’s surfaces during precambrian time?

Which of the following can occur to two segments of a population if they are geographically isolated 1.) they can only share some types of genes 2.)both groups most likely become extinct 3.)they find a way to come back together 4.)eventually they become separate species

The cell membrane controls what enters and leaves the cell. which of the structures in the diagram below is the cell membrane? — f оооо

Polar zones are cold and tend to be dry because of a pressure system of cold. low high