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The Key to It All!

Now it’s time to apply what you have learned. You will need to observe each of the following leaves closely. Make sure you look for the details needed to create a useful dichotomous key to identify the leaves in the pictures below. Since you probably do not know the names of the trees these leaves came from, your key should identify each leaf by number.


  1. Start by dividing the leaves into two groups.
  2. Then keep dividing the leaf groups into two groups until all of the leaves have been separated.
  3. Design a dichotomous key that can be used to identify each of these leaves. If you forgot how a dichotomous key works, refer to the Bone Key for an example.
  4. When you finish creating your key, give your key to a friend and have them check it to see how well it works!

Leaf 1

Leaf 2

Leaf 3

Leaf 4

Leaf 5

Leaf 6



  1. Which was easier, dividing the leaves into groups or writing the dichotomous key?
  2. Did your friend successfully use your key to identify each of the leaves?
    • If not, which leaf numbers were not successfully identified?
    • Why were some leaves hard to identify using your key?

Review science safety rules here.

Get the plug-ins: Get Adobe Acrobat Reader , and Get Quicktime Player. (The Quicktime plug-in is needed to play sounds and movies correctly.)

Want to share photos of you or your friends doing this activity? Send it in an e-mail with the following information:

  1. The title of the activity
  2. The URL (Internet address)
  3. Your name.

Remember that no pictures can be used that show student faces or student names on it. 

Teachers should view the Teacher Site Map to relate Sci-ber text and the USOE 7th grade science core.

Updated October 24, 2008 by: Glen Westbroek

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