What is a dichotomous key and how is it used?

A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish. Keys consist of a series of choices that lead the user to the correct name of a given item. "Dichotomous" means "divided into two parts". read more

The organism is compared to paired pictures of organisms until a match is found in the key. The organism’s DNA is sequenced and compared to the DNA sequences that are listed in the dichotomous key. Observable characteristics of the organism are checked through a sequence of two-part steps until an identification is listed in the key. read more