Why do biologists use classification keys?
Keys are generally a multiple choice questionnaire that asks about specific characteristics of the organism in question. They make it easy to figure out how the organism should be classified, or to identify the organism in question. Every question answered narrows down the possible identifications, until you get a final answer. It’s just an easy method for doing it. For example, when trying to identify a type of bacteria, the first test done is often the gram stain. The next test done depends on how the first test turns out–the key tells you how to proceed at each step to properly narrow down the possibilties until you have your answer.
