1. Do Now: What is a dichotomous key?

2. Classification
When we classify species, we need a method to group these organisms into more exact groups
How do we do this?

3. Dichotomous Key
A key used to sort, name, and/or classify a particular organism.
This is done by working through a series of steps to identify a mystery organism.

4. How does this work?
Each step consists of two statements that divide things being identified into two groups.
Each statement is followed by a direction that indicates either what step to go to next or the name of the organism.

5. What to do Always start at the beginning of the key!
Make sure you read exactly what the two statements are describing in order to have an accurate identification.

6. How to make a key
Create two statements that will divide your organisms into two groups
Example: If we wanted to separate cars, jets, motorcycles, and bicycles you could start with
1a requires petroleum
1b requires on muscle power

7. How to make a key Each statement will be followed by a direction.
Example:
1a requires petroleum fuel go to step b
1b requires only muscle power bicycle

8. How to make your own key
You would continue to divide your groups further by two statements with two directions.

9. IMPORTANT Make sure you work through step by step.
You may miss-identify the object if you skip over steps
Make sure you know what your step is asking you