Dichotomous Key

What is the purpose of a dichotomous key?

• to find a common ancestor
• to show the evolution of organisms
• to see what organisms eat
• to identify organisms

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

• 1
• 2
• 3
• 4

True or False:

At each number, make sure you read BOTH descriptions, a & b.

• True

• False

True or False:

Once you read both descriptions, follow the directions next to the description that matches your organism.

• True

• False

True or False:

You can identify all of your organisms at the same time.

• True

• False

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

• physical features
• weather patterns
• environment
• diet

Tags

NGSS.MS-LS4-2

What statement would NOT be good for a dichotomous key?

• The organism has 1 dorsal fin
• The organism is ugly
• The organism has leaves in groups of three
• The organism has 6 legs

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. Which arachnid has the student found?

• Whip Scorpion
• Wind Scorpion
• Daddy long legs
• Scorpion

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

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