Dichotomous Key

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

• Eyes on side of head; Eyes on top of head

• One set of dorsal fins; Two sets of dorsal fins

• Mouth at front of head; Mouth on underside of head

• Rounded caudal fin, Forked caudal fin

An illustration of four leaves and a dichotomous key are provided. Use the dichotomous key to identify which of the leaves is from a magnolia tree.

• Leaf 1

• Leaf 2

• Leaf 3

• Leaf 4

A table of arachnid and insect characteristics is shown. Which characteristic could be used to distinguish between arachnids and insects?

• Jointed legs

• Body Segments

• Presence of eyes

• Presence of antennae

A botanist discovers a new plant in the jungle. Which of the following observations of the plant’s characteristics would be useful in determining its identity with a dichotomous key?

• It was discovered in the summertime

• It is wet from a recent rain storm

• Its leaves curl up on edges

• It is eaten by native jungle ants

An illustration of three beetles is given. A student examines three different species of beetles that are related. What structure is identical in all three beetle species?

• Antennae length

• Placement of eyes

• Markings on abdomen

• Width of thorax

Tags

NGSS.MS-LS4-2

A dichotomous key is provided. A fish is caught that has eyes on the side of its head and a wide body covered in spots. What kind of fish is this?

• Cornetfish

• Flounder

• Puffer fish

• Snapper

An illustration of an organism and a dichotomous key are given. What is the organism?

• Arachnid

• Dragonfly

• Fruit fly

• Mayfly