Answer :
A dichotomous key provides a series of questions with two possible paths to systematically identify organisms by narrowing down through a series of binary choices.
A dichotomous key is a classification tool used in biology for identifying unknown organisms. It provides a series of questions or couplets, each with two possible paths. These paths are mutually exclusive and lead to further couplets or, eventually, to the identification of the organism. This technique simplifies the process of identification by dividing a large number of possibilities into manageable, binary choices starting from the most general characteristics and moving toward the more specific until a single choice is left.
Closed-ended questions are a critical part of dichotomous keys, allowing for quick decisions between two alternatives. This method is especially useful for identifying species not known to the observer, like the Gram-positive bacteria on human skin, where you might start with questions about the shape of the bacteria (cocci or bacilli), followed by subsequent questions narrowing down the options to a final identification.
