1. Dichotomous Key Slides

2. Dichotomous Keys Dichotomous
1. a division or contrast between two things that are or are represented as being opposed different.
2. Divided into two parts.
Dichotomous Key
Function: noun : a series of pairs of phrases or descriptions which are used to classify a group of living things by making choices between the sets of traits and characters described in each pair

3. Find the species name for the dog the house cat, and the polar bear
Family
Ursidae- go to 2
Not Ursidae– go to 3
Coat Color
Black- Ursus horribilus
White – Ursus arctos
Genus-
Canis- go to 4
Not canis- go to 5
Black & grey – Canis lupus
White with brown spots- canis familiaris
Size-
Large- panthera pardus
Small- go to 6
Coat color
Gray- Felis catus
Tan with spots & stripes- Felis pardalis

4. Tips for using a dichotomous key
Choose one organism. Start with #1 and follow instructions until you identify the organism.
If you are unsure of an adaptation that is being described, then look at other organisms for examples and clarifications.
Once you are finished identifying your first organism, choose another.
Begin with Step 1 every time you begin to identify a new organism.

6. Tips for creating your own dichotomous key
Step 1- find a characteristic that divides your group into two major groups. NO organism can fall into both groups! 1a- go to step 2 1b- go to step ____. (this step will be created after you have identified all organisms that fit into the 1a classification) Step 2- identify all organisms that fit into this group (you may use multiple steps) before you begin to identify organisms that fit into 1b.

7. Insect Anatomy Diagram

8. Antenna length Leg length
A. Antenna extend past front legs……………………………go to 2
B. Antenna do not extend past front legs…………………. go to
Leg length
A. at least 4 legs are longer than body………………… water strider
B. less than 4 legs are longer than body………………..go to 3