8. BODY MOVEMENTS Class 6 Science Solutions English Medium-Exercise (NCERT Text Book)

Exercise Question: 

Que1: Full in the blanks:

(a) Joints of the bones help in ______ of the body.

(b) A combination of bones and crtilages 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 movements.

Ans: 

(a) movement 

(b) skeleton 

(c) hinge

(d) muscle

Que2: 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.                                                   ( )

Ans: 

(a) (False)

(b) (False)

(c) (False)

(d) (True)

(e) (Ture)

Que3: Match the item in column I with one or more items of column II.

              Column I                              Column II    

             Upper jaw                        have fine on the body

                Fish                              Has an outer skeleton

               Rids                               Can fly in the air

              Snail                               is an immovable joint

            Cockroach                        Protect the heart

                                                   shows very slow movement

                                                   have a streamlined body

Ans: 

               Column I                              Column II    

              Upper jaw                         is an immovable joint

                Fish                               have fine on the body, have a streamlined                                                               body

                Rids                               Protect the heart

               Snail                               shows very slow movement

             Cockroach                        Has an outer skeleton, Can fly in the air

Que4: 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 more not move backwards?

Ans:

(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 allow only back and forth movements. Therefore,  we cannot move our elbow backwards.