Week 3

LO: To know how to identify familiar arthropods using a classification key.

Arthropods are a large group of animals. They include all insects, arachnids (spiders and mites), crustaceans (crabs, shrimp and lobsters) and myriapods (millipedes and centipedes).

Although there are a wide variety of arthropods, they all have some body features in common:

A segmented body

Arthropods have bodies made up from a varying number of segments.

A hard exoskeleton

Arthropods have skeletons on the outside of their bodies. Because of this, they can be classified as invertebrates. Arthropods need to moult (shed their exoskeletons) as they mature, because their skeleton does not grow.

Jointed legs

The word ‘arthropod’ comes from the Ancient Greek words for ‘jointed leg’.

Task: Cut out the pictures of arthropods. Use the classification key to identify them.

Put them in the correct position on the classification key.

Challenge

What is the difference between a millipede and a centipede?

What is the difference between an insect and an arachnid?

Is a crab an arthropod? Why?