Movement in Animals | Class 6 Science lesson NCERT CBSE Lesson Video Lecture - Class 1

all animals show movement the ability to
move has been used as a criterion to
distinguish plants and animals plants
apparently do not show movements in
general while animals move more freely
all animals do not have bones animals
can be grouped into two categories on
the basis of presence of backbone in
vertebrates those animals in which a
backbone is not present
according vertebrates for example snail
jellyfish prawn earthworm spider
cockroach squid starfish fly sea urchin
etc vertebrates are those animals having
a backbone for example fish mammals
reptiles birds and Phoebe ins etc let us
now learn about the body movements of
some invertebrates an earthworm has a
long tube-like body which is made up of
many rings or segments joined end-to-end
muscles are present in the body wall
which helps it elongate and contract it
has no bones but the body secretes a
slimy substance which keeps its body
moist protects it and also helps in its
movement body shape is maintained by a
fluid present inside the body thus this
type of skeleton is also called a liquid
skeleton while moving an earthworm
extends muscles of its segments which
move ahead and grip the ground then the
segments following it contract and pull
the rest of the body ahead while
expansion it also lifts its body up from
the ground
thus earthworm moves by contraction and
expansion of its muscles which may take
place at more than one place in its body
at any given time during movement the
animal is able to keep its grip on the
ground because of the presence of a
number of minut hair like bristles on
the under surface of the body the
bristles are connected to the muscles
some interesting facts earthworms
breathe through their skin they have no
eyes but a light-sensitive they cannot
survive in strong sunlight if an
earthworm loses any part of its body it
will grow back
snails are famous for the slow movement
snails have a protective shell on their
back the shell is actually the
exoskeleton the snail has a soft body
and a thick flat muscular foot when the
snail has to move the foot comes out of
the shell through an opening in the
shell it produces mucus so that the
animal gets a smooth surface to walk the
muscular foot produces a cities or
wave-like movement that held the snail
to move forward the shell is dragged
along with the body
some snails have been known to live up
to 15 years
snails cannot hear garden snails have up
to 14,000 175 teeth they are all located
on the tongue snails are vegetarians
they are nocturnal animals
a cockroach does not have bones and the
body is covered with a hard outer
skeleton call exoskeleton they have
three pairs of legs and two pairs of
wings the exoskeleton is made up of
different units joined together and it
helps in movement
a cockroach keeps only three legs on the
ground at a given time and the other
three legs next as in an ant this gate
is called the alternating tripod gate
the wings of the cockroach is attached
to the muscles on its chest which move
when it flies the muscles those which
move the legs are different from the
muscles which move the wings these are
insects which come out at night to feed
themselves they run very fast and a
consider to be the fastest running lan
insects Thank You children to know about
the movement in vertebrates click on the
link given