What do we refer to when we separate things into groups based on their common characteristics?

All living organisms are classified into groups based on very basic, shared characteristics. These specialized groups are collectively called the classification of living things. The classification of living things includes 7 levels: kingdom, phylum, classes, order, families, genus, and species .

Explanation:

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.