Dichotomous Key Pre-Assessment

Which of the following is most helpful for identifying an organism using a dichotomous key?

• Its average lifespan.

• Its sources of food.

• Its habitat.

• Its physical structures.

A drawing of a leaf and a dichotomous key are provided. What leaf is shown in the drawing?

• Liquidambar

• Magnolia

• Pine

• Redbud

An illustration of two insects is provided. Which of the paired statements could be used to distinguish the insects using a dichotomous key?

• Has 6 legs, has 8 legs

• Large hind legs, small hind legs

• 2 pairs of spots on wing cover, 3 pairs of spots on wing cover

• Antennae absent, antennae present

A student makes observations of a tree in a nearby forest. Which of the following observations of the tree’s characteristics would be useful in determining its identity with a dichotomous key?

• It provides shade for ground brush.

• Its leaves are long and narrow.

• Its branches were recently cut.

• It contains the nests of several birds.

A labeled illustration of a shark is provided, along with a dichotomous key. Using the dichotomous key, what shark is shown?

• Cow shark

• Great white

• Hammerhead

• Saw shark