Classification of living things

Biologists group living things to understand them. Big groups:

• Plants: make food, no movement (mostly), cell walls.
• Animals: need food, can move, no cell walls.
• Fungi: mushrooms, moulds — decomposers.
• Bacteria: single-celled microbes.
• Protists: single-celled, complex (amoeba, algae).

Animals further split into:

• Vertebrates (have backbone): fish, amphibians, reptiles, birds, mammals
• Invertebrates (no backbone): insects, worms, jellyfish, molluscs