Dichotomous Keys

What is a key?

• We use keys in everyday life, to help us “unlock” things.

• Obviously keys can be used to unlock a door, but there are other types of keys, like the ones you may find on a map that you used in geography class. These keys provide us with useful information.

Dichotomous Keys

• Biologists also use keys. These are keys that help them to “open doors”, that eventually lead to finding the identity of an organism.

• This is really useful when dealing with organisms that have similar characteristics.

• These keys are called Dichotomous keys.

Dichotomous Keys

• Dichotomous keys establish relationships between organisms based on shared characteristics.

Dichotomous Keys

• Each dichotomous key involves making a choice between two choices using if…then…logic.

A Useful tool for Biologists!

• When it comes to identifying organisms that look very similar, dichotomous keys make things much easier.

• Lets look at how a dichotomous key can be used to identify aliens. Click on the aliens!

Dichotomous Key Activity• This activity will allow you to explore and

practice using dichotomous keys.• To access this activity we will go to the

Explorelearning website.• Click on enroll in a class and enter in the class

code. I will give you the code.• Set up your account and launch the Gizmo.• Please complete the Gizmo and submit Activity CParts 1 & 2.