Question 1:
Which of the following parts of our body help us in movement?

1. Bones
2. Skin
3. Muscles
4. Organs

Choose the correct answer from the option below.
(a) (1) and (3)
(b) (2) and (4)
(c) (1) and (4)
(d) (2) and (3)
Solution:
(a) Our bones and muscles together form the musculoskeletal system that enables the movement of body parts and the whole body from one place to another.

Question 2:
Which of the following joints are immovable?
(a) Shoulder and arm (b) Knee and joint
(c) Upper jaw and skull (d) Lower jaw and upper jaw
Solution:
(c) Upper jaw and skull joints are immovable or fixed. Bones are held, so tightly together that they cannot move at all. The other options are:
Shoulder and arm Ball and socket joint
Knee and joint Hinge joint
Lower jaw and upper jaw Hinge joint

Question 3:
Which of the following organisms does not have both muscles and skeleton for movement?
(a) Dog (b) Snail
(c) Earthworm (d) Human being
Solution:
(b) Snail does not have both muscles and skeleton for movement. The shell (i.e. external skeleton) serves for muscles attachment and protection. The movement is carried out only with the help of large disc-shaped muscular foot that has two sets of muscles.
In earthworm, a hydrostatic skeleton (fluid filled cavity surrounded by muscles) is present. The alternate contraction and relaxation of muscles and pressure of the fluid helps in burrowing.
Dog and human beings have musculoskeletal system for movement.

Question 4:
Underwater divers wear fin-like flippers on their feet to
(a) swim easily in water
(b) look like a fish
(c) walk on water surface
(d) walk over the bottom of the sea (sea bed)
Solution:
(a) The fin-like flippers worn by underwater divers help to swim easily in water. It mainly helps to keep the balance of the body and to keep direction, while swimming (just as fins in fishes).

Question 5:
Snail moves with the help of its
(a) shell (b) bone
(c) muscular foot (d) whole body
Solution:
(c) Snail moves with the help of a large, disc-shaped muscular foot.
The whole body of a snail is soft and consists of a head, a foot and a shell. Shell is the outer structure (skeleton) of snail, but it is not made of bones.

Question 6:
How many muscles work together to move a bone?
(a) One (b) Two
(c) Three (d) Four
Solution:
(b) Two muscles (a pair) work together to move a bone. When one muscle of the pair contracts, then the other muscle of the pair is relaxed. The alternate contraction and stretching brings about the movement.

Very Short Answer Type Questions

Question 7:
Name the type of joints of your hand which helps you to grasp a badminton racquet.
Solution:
Hinge joint of our hand helps us to grasp a badminton racquet.

Question 8:
What would have happened, if our backbone was made up of one single bone?
Solution:
If our backbone was made up of one single bone, then we would not have been able to bend our body (from waist). Therefore, it is made up of 33 small bones called vertebrae.

Question 9:
Provide one word answer to the statements given below.

1. Joint which allows movement in all directions.
2. Hard structure that forms the skeleton.
3. Part of the body with a fixed joint. .
4. Help in the movement of body by contraction and relaxation.
5. Bones that join with chest bone at one end and to the backbone at the other end.
6. Framework of bones which gives shape to our body.
7. Bones which enclose the organs of our body that lie below the abdomen.
8. Joint where our neck joins the head.
9. Part of the skeleton that forms the earlobe.

Solution:

1. Ball and socket joint
2. Bones
3. Upper jaw with skull
4. Muscles
5. Rib
6. Skeleton
7. Pelvic bones
8. Pivotal
9. Cartilage

Question 10:
Write the type of joint which is used for each of the following movements:

1. A cricket bowler bowls the ball.
2. A girls move her head in right and left direction.
3. A person lifts weights to build up his biceps.

Solution:

1. It involves the shoulder joint, i.e. Ball and socket joint,
2. It involves pivot joint that connects our head to the neck.
3. It involves the elbow joint i.e. Hinge joint.

Short Answer Type Questions

Question 11:
Match the name of the animals given in Column I with its body parts used for movement given in Column II.

Solution:
The correct matching is as given:
(a)-(iii), (b)-(v), (c)-(iv), (d)-(ii), (e)—(i)

Question 12:
Given below is a list of different types of movements in animals:
Running, jumping, walking, slithering, crawling, flying, swimming, creeping.
Write the types of movements seen in each animal.

1. Duck
2. Horse
3. Kangaroo
4. Snail
5. Snake
6. Fish
7. Human being
8. Cockroach

Solution:
The types of movements seen in each animals are as follows:

1. Duck — Flying, walking and swimming
2. Horse — Running and walking
3. Kangaroo — Jumping and walking
4. Snail — Creeping
5. Snake — Slithering
6. Fish — Swimming
7. Human being — Walking and running
8. Cockroach — Walking and flying (short distances)

Question 13:
Bhoojho fell off a tree and hurt his ankle. On examination, the doctor confirmed that the ankle was fractured. How was it detected?
Solution:
The doctor must have observed a swelling around his ankle and taken an X-ray of his ankle. X-ray images confirm any type of injuries/fractures in the bones.

Question 14:
Bones are hard structures and cannot be bent. But, we can still bend our elbow, knee, etc. How is this possible?
Solution:
Elbow and knee are not made up of a single bone rather they are made up of two or more bones which are joined to each other by a joint, i.e. hinge joint. This joint along with the muscles help us to bend the elbow and knee. Hinge joint allows the movement of bones in only one direction.

Question 15:
Which type of movement would have been possible if

1. our elbow had a fixed joint.
2. we were to have a ball and socket joint between our neck and head.

Solution:

1. If our elbow had a fixed joint, we would not be able to bend/fold our arms. A fixed joint does not allow any movement.
2. If we were to have a ball and socket joint between our neck and head, we would be able to rotate our head 360°. A ball and socket joint allows movement in all directions.

Question 16:
Earthworms are known as farmer’s friends. Why?
Solution:
Earthworms make their way through the soil, by loosening the soil and allowing more air to get in. Their body excretes undigested materials that also increases the fertility of soil.
They also help in the decomposition of organic wastes and stabilise a wide variety of wastes. This is called vermicomposting. All this helps the crops to grow, that is why earthworms are regarded as farmer’s friends.

Long Answer Type Questions

Question 17:
(a) Unscramble the jumbled words and write them in the blank spaces provided
(i) neosb ……….. (ii) tnemevom …………..
(iii) iontcaronct ……… (iv) Isecsum …………
(v) arctigeal ………… (vi) epahs …………
(vii) sangro inerlant ……….. (viii) laxaeriont ………..
(b) Read the following paragraph and fill in the blanks using the words you unscrambled.
…(i)… and …(ii)… form the skeleton of the human body. They provide the framework, give …(iii)… to the body and help in …(iv)… . They protect the …(v)… . The bones are moved by alternate …(vi)… and …(vii)… of two sets of …(viii)... attached to them.
Solution:
(a)
(i) bones
(ii) movement
(iii) contraction
(iv) muscles
(v) cartilage
(vi) shape
(vii) internal organs
(viii) relaxation
(b)
(i) Bones and
(ii) cartilage form the skeleton of the human body. They provide the framework, give
(iii) shape to the body and help in
(iv) movement. They protect the
(v) internal organs. The bones are moved by alternate
(vi) contraction and
(vii) relaxation of two sets of
(viii) muscles attached to them.

Question 18:
How is the skeleton of a bird well-suited for flying?
Solution:
The skeleton of a bird is well-suited for flying because

1. Their bones are hollow and light in weight.
2. Their forelimbs are modified as wings.
3. The shoulder bones are strong, thus helpful in flying.
4. The breast bones are modified to hold flight muscles which are used to move the wings up and down for flying.
5. They have a streamlined body, which reduces the air resistance.

Question 19:
In the figure given below, there are two snakes of the same size slithering on sand. Can you identify which of them would move faster and why?

Solution:
Snakes do not have limbs but have rough scales on the underside of the body that help them in their locomotion. A snake form loops in its body while slithering. Each loop of the snake gives it a forward push by pressing against the ground. The snake with a larger number of loops will move much faster than the snake with lesser number of loops.
Thus, snake A will move faster than snake B as we can see more loops are formed by snake A.