animals withought backbones aka invertebrates.
they are classified into 5 smaller groups:
1. cnidarians - these live mostly in the sea and have tentacles...they paralyse their prey and eat it...as in just push it in their mouth.
2. worms - three major types of worms
- flatworms - which have flat bodies with a mouth on one end
- roundworms - which have long, thin bodies, and live underground mostly
- segmented worms - they have long tube shaped bodies that are made up of segments.
3. molluscs - these include animals like slugs, snails etc...their bodies are soft and have either one or two shells to protect them...9according to a book i looked up the other day, they also have a muscular 'foot')
4. echinoderms - these are the type of animals that live in the sea and have tough skins. eg . starfishes
5. arthropods - they are the largest group of invertebrates...bodies are divided into segments and the outer body is is supported by a hard skeleton called exoskeleton, if they grow too big for the exoskeleton, then they grow a new one...they also have feelers aka antennae...even anthropods have smaller groups...four smaller ones to be secific...i'm just going to name them
- crustaceans
- myriapods
- insects
- arachnids
those with back bines aka vertebrates...im only going to name them since you should know about them already...as in like...what they are
- fish
- amphibians - the ones that can live under water and on land eg. frogs
- reptiles eg. snakes or crocodiles
- birds
- mammals eg. us

i hope that helped...im not an a-level student...but i wrote what i knew...i hope it helps.
