Question

• Explain what a dichotomous key is and how to use it.

• Salamander Key should be out on your desk to be
checked!

Answer 1

Answer and Explanation:

The term dichotomous means branching or separating into two. A dichotomous key consists of a series of characteristics listed and numbered in pairs. Each member of the pair refers to a variation of the trait. To construct the key, the following steps are used:

• Note down the conspicuous morphological characteristics possessed by the organism.
• List and number the characteristics in a series of contrasting pairs of statements
• Use technical terms to avoid lengthy statements.
• The characteristics used should not generalize or overlap.
• The first characteristic listed should be a major one, which places the organisms in two large groups.
• Each statement should also give the identity of an organism or instructions as to the next pair of contrasting characteristics to consult.