Download PowerPoint Template for Activity 8: Dichotomous Key

Activity 8: Dichotomous Key (SI GLEs: 13, 19, 20; LS GLE: 22)
A dichotomous key is a useful tool in determining the scientific name of a specific organism being studied. In this activity,
students will learn how to use a prepared dichotomous key to determine an object’s identity and then create their own
dichotomous key.
Find an example of a simple dichotomous key for students to use by accessing one of the websites listed in the resource
section or by using the one that follows. Have students practice using it; then have them create a simple dichotomous key to
identify plant, animal, protist, fungus, and moneran cells. Students can find directions for creating a dichotomous key by
accessing one of the websites found in the resource section of this unit.
Have the class classify a specific organism together. The key will give two choices: either Step 1 or Step 2. Name six
animals: dog, cow, human, fish, turtle, and bird, and follow the key.
Go to 2.
1a. Lays eggs.
1b. Does not lay eggs.
Go to 4.
2a. Has feathers.
Bird
2b. Does not have feathers.
Go to 3.
3a. Has legs.
Turtle
3b. Does not have legs.
Fish
4a. Has two legs.
Human
4b. Has four legs.
Go to 5.
5a. Eats meat.
Dog
5b. Does not eat meat.
Cow
Discuss the usefulness of dichotomous keys in science. Then have students create a simple dichotomous key to
identify different types of trees, flowering plants, organisms in the cat family, or types of birds.