NCERT Solutions for Class 6 Science Chapter 8 Body Movements

Q1 ) 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 $muscles$ pulls the bones during movement.

Q2 ) 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. (F )
The movement and locomotion of all animals are not same. Because the locomotion and movement of any animal are, depend on their body structure. And the structure of all animals be different so the locomotion is also different.

(b) The cartilages are harder than bones. (F )
No, cartilages is softest bone of body.

(c) The finger bones do not have joints. (F )
The finger bones have joint.

(d) The fore arm has two bones. ( T)

(e) Cockroaches have an outer skeleton. ( T)

Q3 ) Match the items in Column I with one or more items of Column II.

Column I

Upper jaw
Fish
Ribs
Snail
Cockroach

Column II

Have fins on the body
Has an outer skeleton
Can fly in the air
is an immovable joint
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

Q4 ) 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) That joint of bone allows it to rotate in all directions is called ball and socket joint. One part of it is a ball like structure which is fit into the socket. And allow to move in all direction.

(b) Lower jaw

(c) The elbow cannot move backwards because it has the hinge joint that joints allow movement in one plane only. It is structure like the hinges of door