1. Learning Objectives What is a Dichotomous Key
What is a Branching Diagram
How to they connect to each other
Learn how to make each

2. Dichotomous Key:
A guide of paired choices to help identify an organism. Often it can be used to make a Branching Diagram.

3. Dichotomous Key: Example: Idenitfy a brown, 8 legged insect:
1a Has 8 legs or fewer………….Go to choice # 2
1b Has more than 8 legs………..Go to choice #10
2a Has 8 legs…………………..Go to choice # 3
2b Has 6 legs or fewer………..Go to choice # 5
3a Has a brown body……….“Trap-door” Spider
3b Has a grey body……………Go to choice # 4
Choices would contiue on…

4. ***every option has only 2 choices***
Ex: Idenitfy a brown, 8 legged insect:
1a Has 8 legs or fewer………….Go to choice # 2
1b Has more than 8 legs………..Go to choice #10
2a Has 8 legs…………………..Go to choice # 3
2b Has 6 legs or fewer………..Go to choice # 5
3a Has a brown body……….“Trap-door” Spider
3b Has a grey body……………Go to choice # 4
Notice:
***every option has only 2 choices***
***eventually all choices lead to a single species***

7. Branching
Diagrams:
Work together with Dichotomous Keys to help with classificiation and shows evolutionary relationships
Notice:
***every option has only 2 choices***
***eventually all choices lead to a single species***

9. H E J

10. J D B G A F I C

11. 3a 3b 2a 2b 1a 1b 6a 6b 5a 5b 4a 4b 8a 8b 7a 7b 9a 9b

12. Dichotomous Key: For Creatures
1a Has wheels………………Go to choice # 2
1b Has no wheels……………Go to choice #4
2a Has wings…………………Go to choice # 3
2b Has no wings……..……….Creature “J”
3a Has a tail…………………..Creature “H”
3b Has no tail…………………Creatuer “E”
Dichotomous key MUST contiue on…