Using Taxonomic Keys

Contributor: Hannah Brooks. Lesson ID: 12131

When you examine something, do you notice details? These small details can make a difference when comparing things that seem similar. Learn how scientists use details to sort out plants and animals!


Life Science

learning style
personality style
Grade Level
Middle School (6-8)
Lesson Type
Dig Deeper

Lesson Plan - Get It!

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  • Do you know the difference between bugs and spiders?

They do, and you are so much smarter! So, take a further look at taxonomy to prove it!

Organisms are classified based on characteristics like number of legs, colorful markings, and mode of locomotion.

Just think how many different kinds of trees can be found in your neighborhood!

Ecologists (scientists who study living systems), botanists (scientists who study plants), and zoologists (scientists who study animals), use taxonomic keys to identify different organisms as they work in the field.

These keys help them narrow down the possible species by moving through a step-by-step process.

Another name for taxonomic keys is dichotomous keys, so you may hear either name throughout this lesson and in the field.

As you watch a quick video on using a Dichotomous Key, from Mark Drollinger, record your answers to these questions:

  • What is the dichotomous key used for?
  • What does it look like?
  • What information would you need to build or create one?

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  • Why do you think it is important to have only two choices in each step?
  • How could you use a dichotomous key to identify a spider versus a bug? What characteristic do you think makes them unique?

When you feel ready to use a dichotomous key yourself, move on to the Got It? section to identify different species of fish.

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