Dichotomous “ME” Activity
Creating a dichotomous key of your very own local organisms
Objectives
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Students will identify properties that can be used to classify local native organisms in a binary
classification system;
Students will construct a dichotomous classification system for their group’s local organisms;
Students will be able to identify local native organisms using a dichotomous key
Students will understand the binomial nomenclature of classification of local organisms
Activity
1. You will be given a number of magazine resources that contain pictures of both local plants and
animals. If you wish, you may also use the internet as a resource for local plant and animal
pictures. You will work in lab groups of 3-5 and be given the task of cutting out pictures of these
local organisms. You may want to glue your photos of organisms to a folder, and then proceed to
cut them out, so that each is sturdier. You and each other student in your group is responsible for
cutting out four photos…of which, one must be a plant. Make sure you do not choose the same
organisms as others in your group. Remember, humans are local animals, and they can also be
one of the organisms…but no more than one in a group!
2. After you’ve completed cutting and pasting, you will research each of your local organisms, and
make sure you know some of their major characteristics (i.e…mammal; four legs; brown hair;
herbivore; live birth to young; etc.) You should also know your organisms’ binomial
nomenclature, because a scientific dichotomous key will use the scientific naming system to
organize plants and animals. Do your research on your netbooks on the same day you cut your
organisms out. Place your identified local organisms in a Ziploc baggie, and save them for the
next day. Give the baggie to your teacher.
3. On day two, your group will be given a large piece of butcher block paper. Your task is to design
a dichotomous key into which all the group’s organisms will fit. You should do a rough draft
first, so you all know what characteristics you are going to use in your dichotomous key.
4. To test your dichotomous key, swap your finished product along with the Ziploc baggie full of
organisms with a neighboring group. Your challenge is to identify the baggie of organisms using
the dichotomous key constructed by the corresponding group.
Analysis and Reflection:
1. Were plants and animals equally difficult/easy to classify? Why/Why not?
2. What four local organisms did you contribute to your dichotomous key activity? (identify them
using their binomial nomenclature)
3. What characteristics did you select to help classify your local organisms?
4. What did you like best about this activity? What did you like least?
5. How could you change, or add to this activity, to make it even more productive?