Anthropods
Biology: Cambridge International GCSE Supplement, topic 1.3.4
Arthropods
Invertebrates are animals that do not have backbones. The arthropods are invertebrates that have hard exoskeletons (skeletons on the outside of the body) made of chitin, segmented bodies and jointed legs. There are more arthropods than any other animal group, and they can be split into four main groups:
Insects
- Insects have one or two pairs of wings, three pairs of jointed legs, and three body segments (head, thorax and abdomen).
- They have a pair of compound (made of many lenses) eyes, and a pair of antennae.
- Bees and beetles are examples.
Arachnids
- Arachnids have four pairs of legs, no wings or antennae and multiple pairs of simple (not compound) eyes.
- They have jaws and mouthparts adapted to biting prey and injecting venom.
- Spiders and scorpions are examples.
Crustaceans
- Crustaceans have two pairs of antennae, no wings, compound eyes and four or more pairs of legs.
- They have a very hard, calcified (contains calcium) exoskeleton.
- Crabs, woodlice are examples.
Myriapods
- Myriapods have one pair of antennae, simple eyes and one pair of jointed legs per body segment.
- They have no obvious thorax or abdomen but many body segments.
- Centipedes and millipedes are examples.
Test yourself on Anthropods
Which of these is not one of the three body segments of insects?
Which of these arthropod groups have wings?