Chapter 8: Body Movements

Science

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  Chapter 8: Body Movements

 (Class-6)

NCERT solutions

Question 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.

Question 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

(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

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

(a) A ball and socket joint is a moveable joint. It has a rounded end of one bone fit into the cavity (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.