Dichotomous Key

What is the purpose of a dichotomous key?

• to find a common ancestor
• to show the evolution of organisms
• to show relationships between organisms
• to identify organisms

A dichotomous key for trees is provided. Hikers found a tree that has large brown cones and single sharp needles. What species of tree have the hikers found?

• Juniper
• Pine
• Spruce
• Fir

A dichotomous key for insects is given. To what order does an insect with two pairs of scaly wings belong?

• Coleoptera
• Heteroptera
• Diptera
• Lepidoptera

A student discovers an arachnid with a segmented abdomen, long legs, and a tail with no stinger.

The student uses the dichotomous key below to identify it.

1. a) Abdomen segmented.............go to 2

b) Abdomen not segmented ......go to 4

2. a) Abdomen with tail....................go to 3

b) Abdomen without tail...............go to 5

3. a) Tail with stinger..........................Scorpion

b) Tail without stinger.....................Whip scorpion

4. a) Legs longer than body.............Daddy Long Legs

b) Legs not longer than body……….Wind scorpion

5. a) Covered with spines .......................Mite

b) Few spines.....................................Tick

• Whip Scorpion

• Daddy Long Legs

• Mite

• Tick

Which leaf is shown in the drawing?

• Magnolia

• Redbud

• Sweetgum

• None of the above

Which shark is the picture of?

• Cow Shark

• Great White Shark

• Hammerhead Shark

• Saw Shark

An illustration and a dichotomous key are given. What is the correct classification for this organism?

• Class Insecta
• Order Amblygygi
• Order Araneae
• Order Scorpiones

Tags

NGSS.MS-LS4-2

What is the name of bird X?

• Certhidea

• Geospiza

• Camarhynchus

• Platyspiza

Tags

NGSS.MS-LS4-2

Leaf S

• Eastern white pine

• balsam poplar

• sweet gum

• ginko

In a dichotomous key, organisms should be classified based on their

• diet

• habitat

• observable features

• sounds they make