Sci-ber Text - 7th Grade

Classify - Using a Taxonomic Key

A taxonomic key can also be called a dichotomous key. A taxonomic key is designed to look at the similarities and differences between objects using a series of paired statements. The paired statements describe contrasting characteristics (it is best to use observable, physical characteristics). You choose one statement of the pair that happens to be true of the object you are trying to identify. The statement you choose may ask you to go on to another pair of statements or it may give you the name of the object.

For example - here is a taxonomic key to some common forms of money you may have handy. Gather some money (penny, nickel, dime, quarter, $1 bill, etc.). Choose one denomination of money and try to follow the key to identify what you have. Although you already know the names of the denominations of money you are looking at, practice using the taxonomic key.

Money Taxonomic Key
Is it made of metal?
	Yes	...............................................	Go to 2
	No	...............................................	Go to 5
Is it a silver type color?
	Yes	...............................................	Go to 3
	No	...............................................	Penny
Is the outer edge smooth?
	Yes	...............................................	Nickel
	No	...............................................	Go to 4
Is there an Eagle on the back?
	Yes	...............................................	Quarter
	No	...............................................	Dime
Do the corners have a number 1 in them?
	Yes	...............................................	$1 Bill
	No	...............................................	$2 Bill

Now, you are to use a taxonomic key to identify plants of Utah. This key is designed to help you find differences between common evergreen trees in the state of Utah (not every evergreen tree in the state is included!). Have a competition with some of your friends. See who is able to use the key to identify the most trees!

Analysis:

Which trees were most similar and the most difficult to identify?
Which trees were you able to identify the most easily?
How many trees did you have which were not on this list?
- Borrow a tree identification guide from your teacher or the library and see if you can identify the names of the trees which were not on the list.