In the parlor game “20 questions,” participants try to identify a mystery object by asking up to 20 yes-or-no questions. A dichotomous key uses a similar principle to help identify plants, animals, and other objects. At each step of the key, the student has two choices. Each choice leads to a new set of choices until the identification is complete.
In the Dichotomous Keys Gizmo, students can use keys to identify species of California albatrosses, Canadian buttercups, venomous snakes in Texas, Virginia evergreens, and Florida sharks and rays. For a fun contest, see who can correctly identify the most species in five minutes!