Class-6 Science, Chapter-8 Body Movements , Additional Exercises with Solutions in line with NCERT book / CBSE Syllabus

Chapter 8
Body Movements

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Additional Exercises

Exercises from Textbook

Additional Exercises

Choose the correct answer:

1.    Which of these animals moves with the help of a muscular foot?

a.    Fish

b.    Snail (√)

c.    Snake

2.    ___________ moves by alternate extension and contraction of the body using muscles and bristles under side of the body help in gripping the ground.

a.    Earthworm (√)

b.    Snake

c.    Fish

3.    Which of the following animal slithers on the ground by looping sideways.

a.    Cockroach

b.    Snail

c.    Snake (√)

4.    Which of the body part has fixed joints or sutures.

a.    Skull (√)

b.    Shoulder

c.    Elbow

5.    Which of the following join is not a ball and socket joint?

a.    joint between arm and Shoulder

b.    Joint between femur and hip bone

c.    Joint in fingers (√)

Science Class-7

Match these columns:

Column A	Column B
Fixed joints	Joint between arm and Shoulder.
Hinge joint	Joint between hip bone.
Ball and socket joint	Joint between incus and stapes in Middle ear.
Pivotal joint	the joint between and head neck
	fingers, elbows, toes and knees
	Joints between bones in our head.

Ans-

Column A	Column B
Ball and socket joint	Joint between arm and Shoulder.
	Joint between femur and hip bone.
	Joint between incus and stapes in Middle ear.
Pivotal joint	the joint between and head neck
Hinge joint	fingers, elbows, toes and knees
Fixed joints	Joints between bones in our head.

Fill in the blanks:

1.    The framework of bones in our body is called skeleton.

2.    Ribs join the chest bone and the backbone together to form a Rib cage.

3.    Our backbone is made up of many small bones.

4.    Pelvic bones enclose the portion of our body below the stomach.

5.    The skull is made up of many bones joint together by sutures.

6.    Skull encloses and protects a very important part of the body, the brain.

7.    Muscles work in pairs. One muscle contracts while the other muscle relaxes.

8.    The rounded shell is the outer skeleton of the snail.

9.    In cockroach muscles near breast help in flying.

10. Muscles near legs help in moving legs of cockroach for walking.

11. The bones of the hind Limbs in birds are typical for walking and perching.

State whether the following statements are true or false:

1.    Bones can be bent – False

2.    We bend or move our body only those points where bones meet. True

3.    A ball and socket joint provides Movement in all directions. True

4.    The joint where our neck joins the head is a pivotal joint. True

5.    Our elbow has a hinge Joint that allows only a back and forth movement. True

6.    Joints between bones in our head are called sutures or fixed joints. True

7.    Our backbone is made up of only one long bone. False

Answer these questions:

Q. What are joints?
Ans- The places where two parts of our body seem to be joined together are called joints. Examples - elbow, shoulder, neck

Q. What do you understand by streamlined body in a fish?
Ans- The head and tail of a fish are smaller than the middle portion of the body- the body tapers at both ends. This body shape is called streamlined.

Q. How does a streamlined body help fish swim in water?
Ans-

The streamlined shape allows the water to flow around it easily.

During swimming, muscles make the front part of the body curve to one side and the tail part swings towards the opposite side. The body of fish forms a curve. Then, quickly, the body and tail curve to other side. This makes a jerk and pushes the body forward. A series of such jerks make the fish swim ahead. This is helped by the prince of the tail.

Q. Why do underwater divers wear fin like flippers on their feet?
Ans- Underwater divers wear fin like flippers on their feet to the balance of the body and to keep direction while swimming. (They push water in various directions)

Q. Why does a snakes body curves into many loops?
                             orHow does a snake moves forward?

Ans- The snakes body curves into many loops. Each loop of the snake gives it a forward push by pressing against the ground. Since its long body makes many loops and each loop gives it this push, the snake moves forward very fast.

Q. What are the functions of bones?
Ans- Following are the functions of bones:

1.    Bones and cartilage form the skeleton of the human body.

2.    They give frame and shape to the body.

3.    They help in the movement.

4.    They protect the inner organs.

Q. List the features that help bird in flying.
Ans- Following features help birds in flying:

1.      Birds have hollow and light bones.

2.      Bony part of forelimb are modified as wings.

3.      Birds have strong shoulder bones.

4.      The breastbones of birds are modified to hold muscles of flight which are used to move Wings up and down.

Q. What is cartilage?
Ans- Skeleton has additional parts not as hard as bones and which can be bent. These are called cartilage. Example - the portion above ear lobe is made up of cartilage.

Q. How do muscles help us in movement?
Ans- Muscles work in pairs. First muscle contracts while the second muscle relaxes. The bone is pulled in the direction of contraction.
To move the bone in opposite direction (original position), relaxed muscle (second one) contracts, while the first one relaxes.

Q. Explain the gate of earthworm.
                    or

How does an earthworm move?
Ans- An earthworm can extend and shorten and its body.
It first extends the front part, keeping back part fixed to the ground.
Then it shortens the body, keeping front part fixed to the ground and  relaxing the back part.
Its body secretes a slimy substance to help the movement.

Q. How does an earthworm fix parts of its body to the ground?
Ans- Under the earthworm’s body, large number of tiny bristles are projecting out. Bristles are connected with muscles. These bristles help to get good grip on the ground.

Q. How is earth formed useful for plants?
                          OR

How is earthworm, a friend of farmer?
How does earthworm make the soil more useful soil for plants?
Ans- The earth worm, actually, eats its way through the soil! Its body then throws away the undigested part of the material that it eats. This of an earthworm makes the soil more useful for plants.

Exercises from Textbook

Fill In the blanks

Joints of bones help in the movement/ gait
A combination of bones and cartilages forms the skeleton of the body.
The bones at the elbow are joined by hinge joint.
The contraction of the muscles pulls the bones during movement.

Indicate true (T) and false (F) among the following sentences.

The movement and locomotion of all animals is exactly the same. False
Cartilages are harder than bones. False
The finger bones do not have joints. False
Cockroaches have an outer skeleton. True


The items in Column 1 with one or more items of Column 2.

Column 1	Column 2
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

Answer

Column 1	Column 2
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:

What is a ball and socket joint?
Ans- 

Ball and socket joint is a joint in which the rounded end of one bone fits into the cavity (hollow space) or the other bone. 
This type of joint allows movement in all directions. Example - shoulder joint.


Which of the Skull bones are movable?
Ans- Bones of skull are joined to each other by sutures, which allow tiny amount of movement.

Mandible (bone of lower jaw) is the only bone, which is movable.

Why can our elbow not move backwards?
Ans- 

Our elbow cannot move backward because it has a hinge joint, which allows only one way movement.

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