Dichotomous Key Review

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

What step do we always start with when using dichotomous keys?

• 1
• 2
• 3
• 4

When using a dichotomous key to identify organisms, what do we look at?

• physical features
• weather patterns
• environment
• diet

Tags

NGSS.MS-LS4-2

Using this dichotomous key, identity the name of the circled fish.

• band-tail puffer
• spotted goat fish
• peacock flounder
• trumpet fish

What is monster # 1 ?

• Alienus quadlegicus

• Alienus haircus

• Alienus Tritoothicus

• Alienus Blobicus

What is monster # 3 ?

• Alienus Fuzzicus

• Alienus Stripicus

• Alienus Tritoothicus

• Alienus Blobicus

What is monster # 5 ?

• Alienus Fuzzicus

• Alienus Tritoothicus

• Alienus Hairicus

• Alienus Blobicus

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 of the following characteristics will most likely be helpful in identifying a butterfly using a dichotomous key?

• It migrates north in the summer

• It has long tail

• It likes only certain plants

• Its wings beat very fast in hot weather