In this experiment, you compare several unknown powders to known powders. what is the name given to all of the known materials used for comparison in this experiment? a. quantities b. controls c. constants d. variables

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