NCERT Solutions for Class 6 Science Chapter 8 Body Movement
NCERT Solutions for Class 6 Science Chapter 8 Body Movement
These NCERT Solutions for Class 6 Science Chapter 8 Body Movement Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.
Body Movement NCERT Solutions for Class 6 Science Chapter 8
Class 6 Science Chapter 8 Body Movement Textbook Exercise Questions and Answers
Question 1.
Fill in the blanks:
a. Joints of the bones help in the ……………. of the body.
b. A combination of bones and cartilage 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.
Answer:
a. movement
b. skeletal
c. ball
d. muscles
Question 2.
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.
Answer:
a. False
b. False
c. True
d. True
e. True
Question 3.
Match the items in Column I with one or more items of Column II.
| Column I | Column II |
| 1. Upper jaw | (a) have fins on the body |
| 2. Fish | (b) has an outer skeleton |
| 3. Ribs | (c) can fly in the air |
| 4. Snail | (d) is an immovable joint |
| 5. Cockroach | (e) protect the heart |
| (f) shows very slow movement | |
| (g) have a streamlined body |
Answer:
1. (d),
2. (a),
3. (e),
4. (f),
5. (b).
Question 4.
Answer the following questions.
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. The rounded end of bone fits into the cavity of the other bone. Such a joint allows movements in all directions. This type of joint is called ball and socket joint.
b. The facial bones of our skull comprise upper and lower jaw, in which lower jaw is movable.
c. Our elbow has hinge joint. These joints allow movement only in one plane like a door hinge and not more than 180 degrees.
Activity 1
Objective: To show that we are able to bend or rotate our body only at joints.
Materials Required: Wooden scale arid ropes threads.
Procedure:
- Straighten your right arm.
- Ask your teacher or friend to tie a wooden scale lengthwise under the arm in such a way that the elbow is in the centre.
Now, try to bend the arm.
Observations: After tying the scale, we cannot bend the arm at the elbow.
Conclusion: We can see that we can bend or move our body at joints only.
i. Fixed Joints: Fixed joints are the joints where two bones are held so tightly together by strong fibres that they cannot move at all. Fixed joints occur in our skull.
ii. Synovial Joints: Synovial joints are freely movable joints which allow free movements in one or more directions. Following are some synovial joints:
a. Ball and Socket Joint: Ball and socket joint allows movement of the bones in all the directions. Hip joint and shoulder joint have ball and socket joint.
Activity 2
Objective: To make a ball and socket joint.
Materials Required: A strip of paper, a rubber or plastic ball.
Procedure:
- Roll the paper strip into cylindrical shape.
- Make a hole in ball and push the paper cylinder into it.
- Put the ball in a small bowl. The ball and socket joint is ready.
Observation: This formation allowed free movement of the paper in the ball.
Conclusion: The rounded end of one bone fits into the cavity of the other bone is called the ball and socket joint.
b. Pivotal Joint: Pivotal joint allows movement in many planes. Skull makes such joint with the first two vertebrae.
c. Hinge Joint: Hinge joint allows movement only in one direction. Fingers have this type of joint.
d. Gliding Joint: Gliding joint allows a limited movement due to sliding nature of cartilages. Movable joints of the backbone are gliding joints.
Skeletal System: Skeletal system is the framework of bones and cartilages which supports the body. It consists of the following parts:
i. Skull: Skull is the bony part of head which is made of 22 bony plates joined together.
ii. Backbone: Backbone is a long hollow, rod like structure running from the neck to the hips inside the body.
Vertebrae are the small bones which make up the backbone.
iii. Ribcage: Ribcage is 12 pairs of ribs along with backbone making a cone-shaped cage which protects the lungs and the heart.
Activity 3
Objective: To feel the chest bones and the backbone.
Procedure:
- Take a deep breath and hold it for a little while. Feel your chest bones and the backbone by gently pressing the middle of the chest and back at the same time.
- Count as many ribs (bones of the chest) as possible.
- Observe the given figure carefully and compare with what you feel of the chest bones.
- We see that the ribs are curiously bent.
- Ask a friend to touch his toes without bending his knees.
- Put your fingers at the centre of his back. Feel some long and hard structure.
- Starting from the neck, move your fingers downwards on the back of your friend.
Observation: Rib join the chest bone and the backbone together to form a box. This is called the rib cage. Some important internal parts of our body lie protected inside this cage.
Conclusion: Backbone is made of many small bones. The rib cage is joined to these bones.
iv. Carpels: These are the several small bones forming the wrist.
v. Tarsals: These are the several small bones forming the ankle.
vi. Pectoral bones: These are the bones forming the shoulder join.
vii. Pelvic bones: These are the bones forming the hip joint.
Muscles can be classified into two types: i. Voluntary muscles: These are the muscles that can be moved with your own will. For example, you can move your hand up and down with your own will as it has voluntary muscles.
ii. Involuntary muscles: These are the muscles that cannot be moved by your will. For example, you cannot move the muscles of your ear pinna or the muscles of your scalp by your will.
Cartilage: Cartilage is a solid but semi-rigid and flexible tissue which smoothens bones surfaces at joints. It also helps in forming the framework of the body called skeleton. Nose, ear, trachea and larynx have cartilage.
Gait of Animals
i. Earthworm: The body of an earthworm is made up of many rings joined end to end. It lacks bones. It has muscles which help to extend and shorten the body. During movement, it first extends the front part of the body, keeping the rear portion fixed to the ground. Then it fixes the front end and releases the rear end. It then shortens the body and pulls the rear end forward. In this way, the earthworm can move through soil. Its body secretes a slimy substance to help the movement.
ii. Snail: It has a shell which is the outer skeleton of the snail, but is not made of bones. A thick structure, called foot, and the head of the snail may come out of an opening in the shell. The foot is made of strong muscles. The wavy motion of the foot can be seen in a snail.
iii. Cockroach: Cockroaches walk, climb as well as fly in the air. They have three pairs of legs that help in walking. Their body is covered with a hard, outer skeleton is made of number of plates joined together that permit movement. There are two pairs of wings attached to the body that help in flying.
iv. Birds: Birds fly in the air and walk on the ground. Some birds such as ducks and swans can also swim in water. Their bones are hollow and light. The bones of the hind limbs are used for walking and perching. The forelimbs are modified as wings. The shoulder bones are strong. The breastbones are modified to hold muscles of flight which are used to move the wings up and down.
v. Fish: The head and tail of the fish are smaller than the middle portion of the body. This body shape is called streamlined. This shape allow the fish to move in water. The skeleton of the fish is covered with strong muscles. The fish forms a curve while swimming. Then, quickly, the body and tail curve to the other side. This makes a jerk and pushes the body forward. This is helped by the fins of the tail. Fish also have other fins on their body which mainly help to keep the balance of the body and to keep direction while swimming.
vi. Snake: Snakes have a long backbone and many thin muscles. Muscles also interconnect the backbone, ribs and skin. The snake’s body curves into many loops, each loop giving it a forward push by pressing against the ground. The snake moves forward very fast and not in a straight line. It is called slithering movement.
Class 6 Science Chapter 8 Body Movement Additional Important Questions and Answers
Very Short Answer Type Questions
Question 1.
Name two types of joints.
Answer:
Fixed joints and movable joints
Question 2.
Name four movable joints.
Answer:
a. Ball and socket joint
b. Pivotal joint
c. Hinge joint
d. Gliding joint
Question 3.
Give two examples of hinge joint.
Answer:
Elbow joint and knee joint.
Question 4.
Name the two main parts of skull.
Answer:
Cranium and facial bones.
Question 5.
What is backbone made of?
Answer:
The backbone is made up of small bones known as vertebrae.
Question 6.
Which internal organs are protected by rib cage?
Answer:
Heart, lungs and liver.
Question 7.
What is patella?
Answer:
Knee cap is called patella.
Question 8.
Which two types of muscles does an earthworm’s body have?
Answer:
Circular muscles and longitudinal muscles.
Question 9.
What is slithering?
Answer:
The movement of snake is called slithering.
Question 10.
Name an animal which swims in water by moving its tail from side to side.
Answer:
Fish.
Short Answer Type Questions
Question 1.
Where are these joints located in your body?
a. Ball and socket joint
b. Pivotal joint
c. Hinge joint
d. Gliding joint.
Answer:
a. Between shoulder and upper arm; between thigh and hip
b. Between the first vertebrae and axis vertebrae
c. Knee joint
d. Movable joints of backbone
Question 2.
What is a cartilage? Where is it present?
Answer:
A solid but semi-rigid and flexible tissue is called cartilage. It smoothens bone surfaces at joints. It is present in the nose tip, ear pinna, trachea and larynx.
Question 3.
Define endoskeleton with example.
Answer:
The skeleton which lies inside the body and is covered by soft parts like flesh is known as endoskeleton. Example, humans, elephants, dogs, etc., have endoskeleton.
Question 4.
Define tendons and ligaments.
Answer:
The bones are connected to muscles with the help of the connective tissues called tendons.
The bones are connected to each other at the joints with tissues called ligaments.
Question 5.
Differentiate between bones and cartilage.
Answer:
| Bone | Cartilage |
| 1. Bones are hard. | 1. Cartilages are soft. |
| 2. Bones cannot bend. | 2. Cartilages can bend. |
| 3. Bones are used to make the framework of the whole body. | 3. Cartilages help to make some parts of the body. |
Question 6.
What are the main functions of the skull?
Answer:
- Skull protects the brain.
- Skull protects the sense organs of the face like eyes, ears and nose.
- Skull gives shape to our head.
Question 7.
How do muscles work?
Answer:
The muscles work in pairs. When one of them contracts, the bone is pulled in that direction. The other muscle of the pair relaxes. To move the bone in the opposite direction, the relaxed muscle contracts to pull the bone towards its original position while the first one relaxes.
Question 8.
How is the brain protected?
Answer:
The brain is located inside the skull of our body. The brain is protected by cranium, a bony box of the skull. Inside the cranium, the brain is contained in a fluid-filled balloon which provides further shock absorption for protection.
Question 9.
Describe the movements of:
(a) earthworm, (b) snail.
Answer:
a. Earthworm has muscles but no bones.
During the movement, earthworm first extends the front part of the body keeping the rear portion fixed to the ground. Then it fixes the front and releases the rear end. It then shortens the body and pulls the rear end forward. In this way, by repeating such muscular expansions and contractions, earthworm moves.
b. A snail moves with the help of a large, disc-shaped muscular foot. It has two sets of muscles in the foot. These muscles contract and expand alternately producing a kind of wave effect (from back to front). A series of waves in the muscles of the foot make the snail move forward.
Question 10.
How do fish move in water?
Answer:
The body of the fish is streamlined. The streamlined shape helps the fish to move in water. The skeleton of the fish is covered with muscles which make the front part of the body to curve to one side and the tail part swings towards the opposite side. This makes a jerk and pushes the body forward. In this way, it moves in the water.
Long Answer Type Questions
Question 1.
What is backbone? Describe its formation. Write its main functions.
Answer:
The backbone is a long, hollow structure running from the neck to the hips, inside our body. The small bones which make up the backbone are called vertebrae. It consists of 33 small ring-like vertebrae joined end to end. The first 24 vertebrae are joined serially by elastic cartilages. The main nerve cord passes through the hollow tube formed by the vertebrae. The 5 vertebrae of the hip are fuse and inseparable. 4 vertebrae of the tail are also fused.
Main functions of the backbone are:
- It provides main support to the body.
- It supports the head at its top.
- It attaches shoulder bones, ribs and hip bones.
- It protects the spinal cord.
Question 2.
Explain the various kinds of joints found in our body and give an example of each.
Answer:
a. Fixed joints: Those joints which do not allow movement are called fixed joints. Example: Skull bones.
b. Bali and socket joint: In this joint, one end of the bone has a round shape like a ball which fits into a socket in the other bone. It permits movements of the bones in all directions. Example, shoulder joints and hip joints have ball and socket joints.
c. Pivotal joints: Pivotal joint allows rotation only. It occurs between the first vertebrae and axis vertebrae.
d. Hinge joint: This joint allows movement only in one direction, forwards and backwards. Elbow joint and knee joint have this type of joint.
e. Gliding joint: This joint allow a limited movement due to sliding nature of cartilages. Movable joints of backbone are gliding joint.
Question 3.
What is a skeletal system? Write the functions of the skeletal system.
Answer:
The framework of bones and cartilages which supports the body of an animal or human is called the skeletal system.
The main functions of the skeletal system are:
- It holds the whole body together and gives it a shape.
- It protects the delicate internal organs like brain, kidney, heart, lungs, etc.
- It provides numerous points for the attachment of muscles of the body.
- Along with muscles, skeleton helps in the movement of body parts and in locomotion.
Question 4.
Why do animals need locomotion?
Answer:
- Animals move from place to place in search of food.
- It enables the animals to migrate from an unfavourable place or environment to a favourable place or environment.
- It helps the animals to escape from their enemies and predators.
- It helps animals to find their partners for reproduction, and to move to favourable areas for egg laying or rearing of young ones.
Question 5.
Describe the hip bone. Write its main functions.
Answer:
The hip bone forms a large basin shaped frame at the lower end of the backbone to which the legs are attached. The hip bone is also called pelvis. The hip bone encloses the position of our body below the stomach. The thigh bones of our legs are joined to the hip bone by the ball and socket joints.
The main functions of hip bone are:
- Hip bone supports and protects the lower organs of the body such as intestines, urinary bladder and internal sex organs.
- It attaches the legs to our body.
- It provides sides for the attachment of muscles that move legs, hips and trunk.
Question 6.
Explain the structure of leg.
Answer:
The leg includes the thigh, lower leg, ankle, foot and the toes.
- The thigh bone called femur, is the longest and strongest bone in the body.
- The lower leg consists of tw o bones: tibia and fibula.
- The ankle consists of several small bones.
- In the front part of the knee, there is a disc-like knee cap called patella.
- The foot has five longer bones called metatarsals.
- Each toe has three smaller bones.
The toe bones also help us in walking and running. They are called tarsals.
Picture-Based Questions
Question 1.
a. Identify the figure shown here:
b. What type of joint is present between these bones?
c. Give one function of this structure.
Answer:
a. Backbone
b. Gliding joint
c. It protects the spinal cord
Question 2.
a. Identify the figure shown below:
b. Name the type of joint in part marked A.
c. Is the joint marked B movable or not?
Answer:
a. Skull
b. Fixed joint
c. It is immovable.
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