PATTERNS IN NATURE

BY

DU

VI A

BA

BU

INVERTEBRATES

Animals that don’t have backbone are called invertebrates

For example: prawns

crabs

shrimps

snails and

earthworms

MOLLUSESo They move with their muscular feet.o Animals like squids, slugs and

octopuses have a soft outer covering.

o Snail 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