There are millions of different types of living things on Earth. In order to keep track of them all, scientists put living things into groups based on characteristics that they have that are the same.

Students will learn how to categorize matter as either pure substances or mixtures. Students will apply tests, based on physical properties of matter samples, to determine whether a mixture is ...

Recent papers have shown the feasibility of classifying humans into categorical populations from their genotypes. How can this be reconciled with the claim that human races are biologically ...