CLASSIFICATION
AND DICHOTOMOUS
KEYS
 Classification—the grouping of
things according to characteristics
 Taxonomy—Science of classifying
organisms and assigning each
organism a universally accepted
name
• Binomial Nomenclature—a
system in which each species of
animal or plant receives a name of
two terms: the first identifies the
genus to which it belongs and the
second the species itself.
DICHOTOMOUS KEY
 Organized set of couples of
mutually exclusive
characteristics of organisms that
can be used to easily identify
organism

Dichotomous comes from 2
Greek words that mean “divided
in two parts”
STEPS TO USING DICHOTOMOUS
KEY
1. Use picture to identify
2. Start with statement 1A of Key and read
statement.
3. If the statement is true, follow
instructions at the end. If the statement
is false, go onto statement 1B. Follow
instructions at end of 1B.
STEPS TO USING DICHOTOMOUS
KEY
4. Continue to follow the statement
according to directions written in
the key until you name the object.
5. Do this for each picture, but
remember:
ALWAYS START AT THE
FIRST STATEMENT!!