EVERYDAY SCIENCE

Detailed explanation-1: -When creating your dichotomous key, you need to start with the most general characteristics first, before moving to the more specific ones. So it helps to have identified the more obvious and less obvious contrasting characteristics among the specimen before creating your dichotomous key.

Detailed explanation-2: -“Dichotomous” means, “divided into two parts.” A dichotomous key always gives two choices in each step. In each step, you must make a decision based on characteristics of the item. If you decide correctly every time, the name of the item will be revealed at the end.

Detailed explanation-3: -The first step in the identification of an unknown bacterium is often to determine its morphology and Gram stain reaction.

Detailed explanation-4: -Dichotomous literally means dividing into two parts (Merriam-Webster, 2014). A dichotomous key provides users with a series of statements with two choices that will eventually lead to the correct identification of the organism.

Detailed explanation-5: -Basic Rules for Constructing Dichotomous Keys All parts of the key should be dichotomous. Never use trichotomies. Always give contrasting, alternative characteristics in each couplet.