Extra 20 important long questions and answers from the chapter8 "Body Movements" for Class 6 Science (CBSE):-

 

1. What are the functions of the human skeleton?

Answer: The human skeleton performs the following functions:

Support:

It provides shape and structure to the body.

Movement:

Bones work with muscles to allow movement.

Protection:

The skull protects the brain, and the rib cage protects the heart and lungs.

Blood Cell Production:

Bones produce blood cells in the bone marrow.

Storage:

Bones store minerals like calcium and phosphorus.

Attachment of Muscles:

Bones provide a surface for muscles to attach, enabling movement.

 

2. What are joints? Describe different types of joints with examples.

Answer: Joints are the points where two or more bones meet and help in movement. Types of joints:

Ball and Socket Joint:

Allows movement in all directions (e.g., Shoulder, Hip).

Hinge Joint:

Allows movement in one direction like a door (e.g., Knee, Elbow).

Pivot Joint:

Allows rotational movement (e.g., Neck).

Gliding Joint:

Allows bones to slide over each other (e.g., Wrist, Ankle).

Fixed Joint:

Does not allow any movement (e.g., Skull bones).

 

3. Explain the movement of a fish in water.

Answer: Fish move in water with the help of their streamlined body and fins:

Streamlined Body:

Reduces resistance and allows smooth movement.

Fins:

Help in changing direction and maintaining balance.

Tail:

Moves side to side, pushing water backward and moving the fish forward.

Muscles:

Work in coordination to move the tail and fins.

Gills:

Allow fish to breathe underwater while swimming.

Slippery Scales:

Reduce friction in water, making movement easier.

 

4. Describe how a bird flies.

Answer: Birds have special features for flying:

Hollow Bones:

Make their body lightweight.

Strong Chest Muscles:

Help in flapping wings.

Wings:

Generate lift by pushing air downward.

Tail Feathers:

Help in balancing and changing direction.

Streamlined Body:

Reduces air resistance.

Beak Instead of Teeth:

Reduces weight and helps in feeding.

 

5. How does a cockroach move?

Answer: A cockroach moves using legs and wings:

Three Pairs of Legs:

Help in running and walking.

Two Pairs of Wings:

Help in short-distance flying.

Exoskeleton:

Provides protection and support.

Muscles:

Help in movement of legs and wings.

Jointed Legs:

Make movement quick and efficient.

Antennae:

Help in sensing the environment for movement.

 

6. How does a snake move?

Answer: Snakes move by slithering due to:

Flexible Body:

Allows bending and curving movements.

Scales:

Grip the surface for movement.

Muscles:

Contract and expand to push the body forward.

Wavelike Motion:

Helps in moving on different surfaces.

No Limbs:

Movement is entirely dependent on muscles and body curves.

Strong Spine:

Supports movement and flexibility.

 

7. What are ligaments and tendons? Differentiate between them.

Answer:

Ligaments:

Connect bones to other bones at joints.

Tendons:

Connect muscles to bones for movement.

Differences:

Feature	Ligaments	Tendons
Function	Connect bones	Connect muscles to bones
Flexibility	More flexible	Less flexible
Strength	Strong but elastic	Strong and tough
Example	Knee joint ligaments	Achilles tendon in the foot

 

8. Explain the movement of an earthworm.

Answer: Earthworms move using their muscular body and bristles:

Muscular Contractions:

Expand and contract body segments.

Bristles (Setae):

Help in gripping the ground.

No Bones:

Movement depends entirely on muscles.

Mucus Secretion:

Reduces friction for smooth movement.

Alternate Contractions:

Help the worm stretch and shorten.

Useful for Soil:

Their movement aerates the soil.

 

9. Why is the backbone made of small bones instead of a single long bone?

Answer: The backbone consists of 33 small bones (vertebrae) for:

Flexibility:

Allows bending and twisting.

Shock Absorption:

Protects the spinal cord from injuries.

Support:

Helps in standing upright.

Balance:

Maintains body posture.

Nerve Protection:

Covers and protects the spinal cord.

Connection to Ribs:

Helps in breathing movements.

 

10. What are the functions of muscles?

Answer: Muscles help in:

Movement of the Body:

Work with bones to enable movement.

Support and Posture:

Maintain body position.

Circulation:

Heart muscles pump blood.

Digestion:

Stomach and intestine muscles help in digestion.

Breathing:

Diaphragm muscles help in inhaling and exhaling.

Facial Expressions:

Facial muscles help in smiling, talking, etc.

 

11. How does a snail move?

Answer:

Muscular Foot:

Helps in crawling.

Mucus Secretion:

Reduces friction for smooth movement.

Slow Movement:

Due to the weight of the shell.

Shell Protection:

Prevents drying and protects from predators.

No Limbs:

Entire movement depends on the foot muscle.

Gliding Motion:

Movement is smooth and slow.

 

12. Describe the role of the skull in our body.

Answer: The skull performs:

Protection:

Protects the brain from injuries.

Support:

Provides structure to the face.

Fixed Joints:

Do not allow movement.

Houses Sensory Organs:

Eyes, ears, nose, and mouth are positioned in the skull.

Jaw Movement:

Lower jaw helps in eating and talking.

Bone Structure:

Made of

22 bones

fused together.

 

13. Explain how joints help in movement.

Answer: Joints allow movement in the following ways:

Ball and Socket Joint:

Allows rotation (e.g., Shoulder, Hip).

Hinge Joint:

Allows movement in one direction (e.g., Knee, Elbow).

Pivot Joint:

Helps in rotation (e.g., Neck).

Gliding Joint:

Allows sliding movements (e.g., Wrist, Ankle).

Fixed Joint:

No movement (e.g., Skull).

Ligaments Support:

Connect bones and provide stability.

 

14. What is a ball and socket joint? Explain its function with examples.

Answer: A ball and socket joint allows movement in all directions.

Structure:

It consists of a ball-like end of one bone fitting into a socket-like cavity of another bone.

Range of Motion:

Provides rotational movement in all directions.

Examples:

Shoulder joint and Hip joint.

Supportive Ligaments:

Hold the bones in place while allowing free movement.

Function:

Helps in free movement of arms and legs.

Importance:

Enables activities like throwing, swinging, and running.

 

15. How do muscles work together for movement?

Answer: Muscles work in pairs for movement.

Antagonistic Muscles:

One muscle

contracts

while the other relaxes.

Example:

In the arm, the

biceps contract

to bend the elbow, while the

triceps relax

.

Coordination:

Muscles and bones work together for movement.

Muscle

Fibres

:

Contain proteins that help in contraction.

Energy Usage:

Require energy (ATP) to contract and relax.

Control:

Brain and nerves coordinate muscle movements.

 

16. What is the role of cartilage in our body?

Answer: Cartilage is a flexible connective tissue found in various parts of the body.

Shock Absorption:

Prevents bones from rubbing against each other.

Flexibility:

Provides smooth movement at joints.

Location:

Found in the nose, ears, joints, and between vertebrae.

Protection:

Reduces wear and tear of bones.

Support:

Forms part of the skeleton (e.g., ribs and trachea).

Growth:

Helps in bone development in children.

 

17. How does the movement of a human arm take place?

Answer: The movement of the arm is controlled by bones, muscles, and joints.

Bones Involved:

 

Homarus

(upper arm), Radius, and Ulna (forearm).

Joint Type:

Hinge joint at the elbow allows bending and straightening.

Muscles Involved:

Biceps and triceps.

Muscle Action:

When the biceps contract, the triceps relax, and vice versa.

Nervous Control:

Brain signals muscles to move.

Ligaments and Tendons:

Help in connecting bones and muscles for smooth movement.

 

18. Why can we not move our upper jaw?

Answer: The upper jaw is fixed and does not move.

Fixed Joint:

The bones of the upper jaw (maxilla) are fused to the skull.

No Movement:

It does not have a movable joint like the lower jaw.

Function:

Provides support to the face and holds upper teeth.

Lower Jaw (Mandible):

The only movable part of the skull.

Importance:

Helps in chewing and speaking.

Evolutionary Benefit:

Stability of the upper jaw allows strong biting force.

 

19. What are the differences between voluntary and involuntary muscles?

Answer: Muscles can be voluntary (under control) or involuntary (not under control).

Feature	Voluntary Muscles	Involuntary Muscles
Control	Under conscious control	Not under conscious control
Example	Arms, Legs	Heart, Stomach, Intestines
Speed	Fast movement	Slow movement
Structure	Long, striated fibres	Smooth, non-striated fibres
Function	Helps in walking, writing, etc.	Helps in digestion, heartbeat, etc.
Energy Use	Requires more energy	Uses less energy

 

20. Why is movement important for animals?

Answer: Movement is essential for survival in animals.

Searching for Food:

Helps in finding and capturing prey.

Escaping from Predators:

Prevents being eaten by other animals.

Finding Shelter:

Allows them to move to safe places.

Reproduction:

Some animals move to find mates.

Adaptation to Climate:

Some animals migrate to

favourable

environments.

Daily Activities:

Helps in activities like swimming, running, flying, and crawling.