Class 6 science Question & answer :
1:Fill in the blanks:
(a) Joints of the bones help in the __________ of the body.
(b) A combination of bones and cartilages forms the of the body.
(c) The bones at the elbow are joined by a ___________ joint.
(d) The contraction of the _ pulls the bones during movement.
Answer :(a) Joints of the bones help in the movement of the body.
(b) A combination of bones and cartilages forms the skeleton of the body.
(c) The bones at the elbow are joined by a hinge joint.
(d) The contraction of the muscle pulls the bones during movement.
2:
Indicate true (T) and false (F) among the following sentences.
(a) The movement and locomotion of all animals is exactly the same. ( )
(b) The cartilages are harder than bones. ( )
(c) The finger bones do not have joints. ( )
(d) The fore arm has two bones. ( )
(e) Cockroaches have an outer skeleton. ( )
Answer 2:
(a) The movement and locomotion of all animals is exactly the same. (False)
(b) The cartilages are harder than bones. (False)
(c) The finger bones do not have joints. (False)
(d) The fore arm has two bones. (True)
(e) Cockroaches have an outer skeleton. (True)
Question 3:
Match the items in Column I with one or more items of Column II.
Column I Column II
Upper jaw have fins on the body
Fish has an outer skeleton
Ribs can fly in the air
Snail is an immovable joint
Cockroach protect the heart
shows very slow movement
have a streamlined body
Answer 3:
Column I Column II
Upper jaw is an immovable joint
Fish have fins on the body, have a streamlined body
Ribs protect the heart
Snail shows very slow movement
Cockroach has an outer skeleton, can fly in the air
Question 4:
Answer the following:
(a) What is a ball and socket joint?
(b) Which of the skull bones are movable?
(c) Why can our elbow not move backwards?
Answer 4:
(a)A ball and socket joint is a moveable joint. It has a rounded end of one bone fit into thecavity (hollow space) of the other bone. It allows movement in all directions. Example:shoulder joints.
(b)Only the lower jaw in skull bones is movable.
(c) Elbow joint is an example of hinge joint which allows only back and forth movements.
Therefore, we cannot move our elbow backwards.