Page 118 - Science Class 06

Gliding Joint

The wrist or ankle joints have fla ened at
the ends of bones that can move (or glide)
against each other. These joints allows side-
to-side as well as backward and forward

movement. The vertebrae also have similar
joints that allow slight movement. Such
joints are called gliding joints. Stremlined body of a fish helps
it in making passage in water.

Birds

Most of the birds fly in the sky. However, a
few birds like penguin and ostrich do not fly.
The body of a bird is divided into head,
neck, trunk and tall. The head bears a pair

of eyes, a pair of nostrils and the joints are
modified into beak. Birds do not have teeth,
Gliding Joint
they have bills to eat.

BODY STRUCTURE OF SOME OTHER
ANIMALS AND MOVEMENT

Like human beings, animals also move one
place to another. They also show movement
in their body parts. Let’s study about body
structure of some animals and their
movement.

Fish

The fishes have a streamlined body, i.e., the
body tapers at both ends that helps them in
Birds
making passage for swimming. They also
Flying birds have wings which are covered
have fins for locomo on which act as oars.
with feathers. The bones of birds are hollow
Most of the bony fishes like Rohu and Singhi
having air cavi es and this makes their body
have an air bladder which is filled with air.
light in weight. The neck of a bird is highly
This bladder helps fishes in swimming. The
mobile. Birds also have hind limbs which
scales on the body of bony fishes for a
help them in perching, running and swim-
water proof jacket which does not let their
ming. The clawed toes of birds help them to
body decay. Fishes also have gills, which
grip the branch of a tree easily and safely.
helps them take oxygen dissolved in water.

118 Science-6