PATTERNS IN NATURE BY DUVIA BABU

INVERTEBRATES Animals that don’t have backbone are called invertebrates For example: prawns crabs shrimps snails and earthworms

MOLLUSES oThey move with their muscular feet. oAnimals like squids, slugs and octopuses have a soft outer covering. oSnail and sea shell have a hard outer covering called EXOSKELETON.  ANIMALS WITHOUT LEGS

Worms (i) segmented worms:body of the worm is made up of ring like section called SEGMENTS :the body has a soft outer covering. For example: earthworm

(ii)non-segmented worms:they have soft and cylindrical body without any segments. For example: round worm :they have soft and flat bodies :several rectangular sections are found behind the head which break off to form a new worm. Eg: tapeworm

 ARTHROPODS They are the largest group of invertebrates. They have joined legs and bodies

(i) INSECTS:they are small creatures which have : a body divided into 3 parts& they are head, thorax and abdomen. 3pairs of legs. some of them have antennae on their head. wings are attached to their thorax. For example: beetle, ants and bee

ARACHNIDS:these are creatures which have: 4pairs of legs body divided into 2 parts scorpions have pincers on their head Eg:spider

Crustaceans have 5 pairs of legs they live in water they have antennae in some cases their front pair of legs are used as pincers. Eg: crabs lobsters and shrimps

Many pairs of legs:these creatures have several pairs of legs :their body is divided into several segments Millipedes:they have two pairs of legs per segment. Centipedes:they have 1 pair of legs per segment