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.
(A) Movement
(B) Skeleton
(C) Hinge
(D) Muscle
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.
(A) F – The movement and locomotion of different animals is different.
(B) F – The cartilages are softer than bones.
(C) F – The finger bones do have joints.
(D) T – The two bones of fore arm are radius and ulna.
(E) T–Cockroaches have a hard and jointed exoskeleton.
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 |
| 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 |
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?
(A) In ball and socket joint, a ball like structure of the one bone fits into a socket like structure of other bone. It allows movement in all directions. Shoulder and hip joints are the examples of ball and socket joint.
(B) The lower jaw bone of the skull is the only movable bone. It allows us to chew food and talk. It is known as mandible.
(C) Our elbow cannot move backwards because elbow has hinge joint and this joint allows movement in one direction only, similar to the hinges of a door. In elbow, it allows to bend and straighten, i.e., up and down movement.