What is the main purpose of a dichotomous key?

The main purpose of a dichotomous key is to identify organisms through a series of choices. This tool is structured to guide the user through a sequential decision-making process, where each choice leads to further distinctions until the organism is identified. By presenting pairs of contrasting characteristics, the dichotomous key enables users to systematically narrow down the possibilities based on observable traits, making it a practical and effective method for identifying species in the field or in laboratory settings.

The other options describe activities that are related but different in purpose. Describing an organism in detail pertains more to documentation than identification. Classifying organisms into broader categories involves grouping them based on shared characteristics rather than focusing on individual identification. Analyzing the genetic makeup of species is a more complex scientific process that requires specific techniques beyond simple observational identification.