Body Movements

1. (a) Joints of bones help in the __movement__ of body.
   (b) A combination of bones and cartilages forms the __skeleton__ of the body.
   (c) Bones at the elbow are joined by a __hinge__ joint.
   (d) The contraction of the __muscle__ pulls the bones during movement.
2. (a) Movement and locomotion of all animals is exactly the same. (False)
   (b) Cartilages are harder than bones. (False)
   (c) Finger bones do not have joints. (False)
   (d) The fore arm has two bones. (True)
   (e) Cockroaches have an outer skeleton. (True)

3. Column I	Column II
   Upper jaw	is an immovable joint
   Fishes	have a streamlined body; have fins on the body
   Ribs	protect the heart
   Snail	shows very slow movement
   Cockroach	has an outer skeleton; can fly in the air

4. (a) Ball and socket joint is a movable joint. It consists of a bone that has a round head, which fits into a cup like depression of another bone. This helps the bone to rotate freely. Examples of such joints are hip and shoulder joints. (b) Mandible bone which forms the lower jaw is the only skull bone that is movable.
   (c) The elbow has a hinge joint. This type of a joint allows the movement in one plane only. Therefore, our elbow cannot move backwards