Exercises:

I.  Fill in the blanks:

a) Joints of the bones help in the __________ of the body.

b) A combination of bones and cartilages from 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.

Answers :
a) Movement               c) Hinge                  b) Skeleton                  d) Muscles  .

II.  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 forearm has two bones.

e) Cockroaches have an outer skeleton.

Answers :
a) False                  b) False                    c) False                 d) True                  e) True .

III.    Match the items in column I with one or more items in column I :

Column – I Column- II
i) Upper jaw a) Have fins on the body
ii) Fish b) Has an outer Skeleton
iii) Ribs c) Is an immovable joint .
iv) Snail d) Can fly in the air .
v) Cockroach e) Protect the heart .
f) Shows very slow movement .
g) Have a stream lined body .

Ans :

Column I Column II
i) Upper jaw a) Is a immovable joint.
ii) Fish b) Have fins on body, have a stream lined body.
iii) Ribs c) Protects the heart
iv) Snail d) Shows very slow movement
v) Cockroach e) Has an outer Skeleton.

IV.  Answer the following :

a) What is a ball and socket joint.
Ans:
The rounded end of one bone fits into cavity (hollow space) of the other bone, such a joint allows movements in all directions. This is called as ball and socket joint.

b) Which of the skull bones are movable.
Ans:
Lower jaw of the skull bones are movable .

c) Why can our elbow not move backwards.
Ans:
The elbow has a hinge joint that allows only a back and forth movement.