Building a Dichotomous Key

This site gives very detailed instructions on how to set up, build, and use dichotomous keys. The directions are very explicit but if students have sufficient background knowledge teachers can alter these activities so that there is more discovery based learning. Dichotomous keys help us understand diversity and identify unknown organisms. In a laboratory/classroom setting students design a dichotomous key.

Weblink address (URL): 
Building a Dichotomous Key

Standards & Objectives

Learning objectives: 

Objectives:

  • The student uses effective strategies for informal and formal discussions, including listening actively and reflectively, connecting to and building on the ideas of a previous speaker, and respecting the viewpoints of others.
  • The student knows of the great diversity and interdependence of living things.

Lesson Variations

Blooms taxonomy level: 
Understanding
Extension suggestions: 

Extensions:
This lesson is designed to be used immediately following the Beacon lesson, Introduction to Classification.

Helpful Hints

Materials:

  • WHOLE GROUP ACTIVITY - Make available pictures OR list on the blackboard or overhead projector the following animals: Snake, Hummingbird Bear, Elk, Manta Ray, Texas Long Horn, Frog, Sting Ray, Tortoise.
  • PRACTICE - Make available leaves or photocopies of leaves, per each group (Long -leaf pine, Florida Torreya, Florida Maple, Mockernut Hickory, Southern Red Oak, Black Willow, Catalpa, Box elder and Black Walnut (see additional resource material)
  • ACTIVITY - Make available leaves or photocopies of leaves, per each group (general assortment) OR add two or four new leaves to the previous group of leaves (PRACTICE) OR teacher may use eight to fifteen items of choice.
  • Overhead projector
  • Visa-Vie 

Resources:

  • Johnson, George B., Biology: [Visualizing Life]. Holt, Rhinehart and Winston, Inc., Orlando, Florida, 1994 and 1998.
  • Kaskel, Albert., Hummer, Paul J. and Daniel, Lucille. [Biology: An Everyday Experience]. Charles E. Merrill Publishing Co., Columbus, Ohio 1988.

Additional Resources: (optional but helpful)

  • Anderson, Robert., [Guide to Florida Trees], Winner Enterprises, January 1988.
  • Nelson, Gil and Cook Marvin., [Trees of Florida: A Reference and Field Guide], Pineapple Press Inc., February 1994
  • Petrides, George A., [Peterson Field Guide to Eastern Trees], Houghton Mifflin Co., Houston, New York, 1998.
  • [Forest Trees of Florida], Florida Department of Agriculture and Consumer Service., 1999 ed.

References

Contributors: 
Dale Rudolph
Originator: 
Ayers Institute for Learning & Innovation