a Dichotomous Key for Families of Idaho Butterflies
grade levels: 9-12, College
view Idaho achievement standards for this lesson
Teachers should explain how
to make a dichotomous key and make a simple one together as a class. As a precursor
to this butterfly activity, it would be a good idea to have students make a dichotomous
key using inanimate objects such as pencils, paperclips, coins, etc. At each stage
in the dichotomous key all remaining "species" must be separated into two clearly
distinguishable groups. The splitting must continue until all "species" have been
separated out. To see a good example of how this is done, refer to the How to
identify species using morphology and creating a dichotomous key in the biology
exercise site. This kind of activity works better if students work in groups of
three or four, but larger groups can be used depending on how many computers are
available in the classroom.
1. Students will learn how
to use the butterfly section of the Digital Atlas of Idaho.
2. Students will learn how to make a dichotomous key.
3. Students will hone their skills of observation and learn how to recognize
defining characteristics that distinguish different families.
Have your students read
through the section on "How to identify species using morphology and creating
a dichotomous key". Once they have become familiar with dichotomous keys they
can go the butterfly family pages to see the characteristics of each family.
- To get there: Click
on Atlas Home, Biology, Butterflies, and then on Family
- From the family tree
page, just click on each of the eight families to obtain information on the
families of butterflies.
- Emphasize to the students
that they must pay careful attention to detail. Groups should use these pages
to obtain defining characteristics of the families of butterflies. Use these
defining characteristics to make a dichotomous key to distinguish these families.
- If there is time, groups
should switch papers and try to follow the dichotomous keys made by other
These are links to access the handouts and printable materials.
Biology: Biology Topics
Lesson plan by James Scannell
and Stefan Sommer, 2001
Idaho Achievement Standards (as of 7/2001) met
by completing this activity: