Page 119 - Science Class 06

Earthworm The head bears a pair of compound eyes, a
Earthworms have liquid skeletons. They
have liquid trapped in spaces inside the
body. The muscles squeeze against the
liquid. This keeps the body firm. Muscles in
a worm’s body can be squeezed differently
to change the body shape. These changes in
the shape help the worm to move along.
To move, the earthworm first extends the
front part of its body, keeping the rear part
fixed to the ground. Next, it fixes the front
part and shortens it, thus pulling the rear
end forward. It carries out such expansion
and contrac on of muscles repeatedly to
move forward.
Locomo on in Earthworm
Cockroach
Cockroach is a reddish brown coloured
insect about 5-6 cm in length. Its body is
elongated and fla ened. The body is
divided into head, thorax and abdomen.
Cockroach
Science-6
pair of long antennae and mouth parts. The
thorax bears two pairs of wings, which are
normally kept folded and three pairs of
waling jointed legs, with the help of these
legs cockroaches move. They use their
wings when they fly.
Snail
Snails are grouped into garden snail and
apple snail. Garden snails are found in the
gardens under the bark or fallen leaves.
Apple snails are found near the river banks
and water stagnant fields.
Snail
The body of garden snail is so and is divide
into head, visceral mass and foot enclosed
in a shell. The shell is thin and spirally
coiled. The head of it bears two pairs of
tentacles, where the first pair bears organs
of smell and the second bears a pair of eyes.
It moves from one place to another by foot
which has a flat ventral surface for creeping.
1. Dis nguish between movement and
locomo on.
2. What do you mean by synovial joints?
3. How does a snail move?
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