What tool is used for identifying organisms through a series of characteristic comparisons?

The tool used for identifying organisms through a series of characteristic comparisons is a dichotomous key. This method involves providing a series of questions or statements that typically present two contrasting options at each step, guiding the user toward the identification of a specific organism based on observable traits. By systematically working through the key, individuals can narrow down options until they arrive at the correct identification.

Dichotomous keys are widely employed in biology due to their practicality in fieldwork and classroom settings. They enable users to identify species without needing extensive prior knowledge, as each choice typically relates directly to specific physical characteristics.

In contrast, a phylogenetic tree depicts the evolutionary relationships among species, typically illustrating common ancestry but not functioning as a direct identification tool. A cladogram is similar in that it shows relationships based on shared derived characteristics but again does not function in the same step-by-step identification manner as a dichotomous key. A classification chart organizes information about organisms but lacks the specific comparative decision-making process that defines a dichotomous key.