Dichotomous Keys Lesson Plans
Day 1: Introduction of a Dichotomous Key using the Silly Science Dichotomous Key found at http://sciencespot.net,
homework is the Creepy Critter Dichotomous Key Worksheet that is attached.
Day 2: Complete the Track/Scat Dichotomous Key in Biology in a Box. See attached student handout for this
activity.
Day 3: To teach my students about dichotomous keys, I challenge my students to develop a key to identify the
letters of the alphabet. I provide a list of ten letters (such as A-J) and instruct them to create a key. They must
create new groups for the letters, such as curvy or loopy, based on the shapes and lines used to write the letters.
After the students have the first ten letters classified, I give the students 3 to 4 additional letters. The students
must use the key they created to determine the classification for the new letters. If the letter doesn't match one of
the original groups, students must readjust their keys to make room for the "new species".
Day 4: Assessment – I have students complete a dichotomous key of their classmates. I create a document with
each student’s photo and have students create a dichotomous key for a substitute teacher.
_________________________________
Name
Scat Dichotomous Key
A. ____________________________________
B. ____________________________________
C. ____________________________________
D. ____________________________________
E. ____________________________________
F. ____________________________________
G. ____________________________________
H. ____________________________________
Animal Track Dichotomous Key
A. ____________________________________
B. ____________________________________
C. ____________________________________
D. ____________________________________
E. ____________________________________
F. ____________________________________
G. ____________________________________
H. ____________________________________
I. ____________________________________
J. ____________________________________
K. ____________________________________
L. ____________________________________
M. ____________________________________
N. ____________________________________
O. ____________________________________
P. ____________________________________
Directions: Help! Scientists have discovered quite a few new creatures on planet Tiptonia. They need
your help to identify and classify them.
1.
2.
Use the dichotomous key below to identify these creatures.
Write the number of the alien next to its scientific name
1.
a. The creature has a large wide head............................go to 2
b. The creature has a small narrow head..........................go to 11
2.
a. It has 3 eyes ................................................go to 3
b. It has 2 eyes ................................................go to 7
3.
a. There is a star in the middle of its chest....................go to 4
b. There is no star in the middle of its chest ..................go to 6
4.
a. The creature has hair spikes .................................Broadus hairus
b. The creature has no hair spikes...............................go to 5
5.
a. The bottom of the creature is arch-shaped ....................Broadus archus
b. The bottom of the creature is M-shaped .......................Broadus emmus
6.
a. The creature has an arch-shaped bottom .......................Broadus plainus
b. The creature has an M-shaped bottom...........................Broadus tritops
7.
a. The creature has hairy spikes ................................go to 8
b. The creature has no spikes....................................go to 10
8.
a. There is a star in the middle of its body ....................Broadus hairystarus
b. The is no star in the middle of its body .....................go to 9
9.
a. The creature has an arch shaped bottom .......................Broadus hairyemmus
b. The creature has an M shaped bottum ..........................Broadus kiferus
10.
a. The body is symmetrical ......................................Broadus walter
b. The body is not symmetrical...................................Broadus anderson
11.
a. The creatrue has no antennae .................................go to 12
b. The creature has antennae ....................................go to 14
12.
a. There are spikes on the face .................................Narrowus wolfus
b. There are no spikes on the face ..............................go to 13
13.
a. The creature has no spike anywhere ...........................Narrowus blankus
b. There are spikes on the right leg ............................Narrowus starboardus
14.
a. The creature has 2 eyes.......................................go to 15
b. The creature has 1 eye........................................Narrowus cyclops
15.
a. The creature has a mouth......................................go to 16
b. The creature has no mouth.....................................go to 17
16.
a. There are spikes on the left leg .............................Narrowus portus
b. There are no spikes at all ...................................Narrowus plainus
17.
a. The creature has spikes ......................................go to 18
b. The creature has no spikes ...................................Narrowus georginia
18.
a. There are spikes on the head .................................go to 19
b. There are spikes on the right leg.............................Narrowus montanian
19.
a. There are spikes covering the face ...........................Narrowus beardus
b. There are spikes only on the outside edge of head ............Narrowus fuzzus
Wacky People
Name:
Wacky People Key
1a Two feet
2
1b Some other number of feet
3
2a Does not look at all human
4
2b Looks a lot like a human
5
3a One leg
6
3b Three or four legs
7
4a Fly-like
Mosk Cara
4b Not fly-like
8
5a Seems to be a girl
Rita Nita
5b Not a girl
9
6a Leg is curled , two feet
Ru-ela.Brella
6b Leg is straight, one foot
Giggles
7a Three legs
10
7b Four legs
11
8a Has webbed feet
Hex Oculate
8b Clawed feet
12
9a Curly hair, no toes
Lugio Wirum
9b Wiggly looking mouth, three toes on feet C. Nile
10a Very long nose, open mouth
Elle E. Funk
10b Some other appearance
13
11a Has duck bill, two pinchers
Tri D. Duckt
11b No arms or pinchers
14
12a Has ears, tail, and beak
Grif Leon
12b Four eyes on stalks
Eggur Ondy
13a One eye, webbed feet
Cue Kide
13b Four stalked eyes, four pinchers
Quadrumenox
14a Three toed feet, nose like a flower
Tunia petalos
14b Spider-like, has spots
Patterned mulywumpus