Question

A dichotomous key is a _____.

Answer 1

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".

Answer 2

Series of step/clues which always has two alternatives out of which only one is correct

Step-by-step explanation:

A dichotomous key is a method by which organisms or objects belonging to a specific class or type are identified by going through each step of the dichotomous key. Each step of the key consists of structured group of clues, sentences, or hints giving description of characteristics or features of organisms or things such as plants, animals or rocks.

Or

A dichotomous key is a process in which at each step of the process a question is asked which has only two alternatives, out of which one is selected to reach the end species/organism classification.