Biology-Mr Willets
Dichotomous Key
A dichotomous key is a device used to identify an organism based on its characteristics. At each point on the key, you are given two choices (that's what dichotomous means). Depending on which you choose, you are sent to another two choices and so on until you find the name of the particular organism you are trying to identify. Using a dichotomous key is like playing the game "Guess Who?"
On a separate page is a dichotomous key that can be used to
identify the different kinds of Quozes.
(Go to dichotomous key) Quozes are a
fictitious kind of organism that we will use for this exercise. Below
is what Quozes look like in general. A phren is a "bump" on the head.
Cilia are tiny hairs on the lower part of the body (the caudus).
Bristles are hairs on the head. Body patterns are either spotted or
linear. Some, like the specimen shown below have no body pattern. A
body pattern can either be symmetrical (the same on both sides of the
body) or asymmetrical (randomly spread out).
If you look at the first set of choices on the next page, you see the choice is between a "phrened" head (one with bumps) or a split head. If your specimen is "phrened", you would go to #2 and read those choices. If your specimen's head is split, you would skip #2-18 and go to #19 and read those choices. You would continue doing this until you found the name of the specimen.
On a separate page, there are 8 different species of Quozes (Go to Quozes species page) Your job is to use the key to name each one. Always start with choices #1 and go from there. In the chart below, name each of the 8 Quozes.
A)_____________________________________ B)_____________________________________
C)______________________________________D)_____________________________________
E)______________________________________F)______________________________________
G)______________________________________H)_____________________________________
In the space below, draw what you think Schizolobus dandi lineus would look like.