Dichotomous Keys

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

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

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

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

• diet

• habitat

• observable features

• sounds they make

How many options should every branch in a dichotomous key have?

• 1

• 2

• 3

• 4

If you were to make a dichotomous key to identify this organism, which option would NOT be used?

• Presence of webbed feet

• Presence of tail

• Fur on the body

• Ability to swim

• Absence of wings

What is the name of bird Z?

• Certhidea
• Geospiza
• Camarhynchus
• Platyspiza

Leaf S (3RD LEAF)

• Eastern white pine

• balsam poplar

• sweet gum

• ginko

Identify leaf F

• Cydonia

• Magnolia

• Aesculus

• Fraxinus

• Ilex