Textbook Solutions: Body Movements | Eureka Plus Class 6: Book Solutions, Notes & Worksheets PDF Download

I. Tick (✔) the correct options. 

1. 
Ans:  (c)

2. 
Ans: (d)

3. 
Ans: (b)

4. 
Ans: (a)

5. 
Ans: (c)

6. 
Ans: (a)

7. 
Ans: (c)

8. 
Ans: (b)

9. 
Ans: (b)

10. 
Ans: (b)

II. Where do you find the following joints in the human body? 

1.
Ans: ball-and-socket joint - This joint is found in the hip and shoulder.

2.
Ans: ball-and-socket joint - This joint is found in the hip and shoulder.

3.
Ans: gliding joint - Gliding joints are found in the wrists and ankles.

4. 
Ans: immovable joint - Immovable joints are found in the human skull, where the bones are held together by sutures and do not allow movement.

III. Answer the following questions in a sentence. 

1.
Ans: 

• Vertebrates: Fish, amphibians, birds, mammals
• Invertebrates: Earthworms, snails, insects, spiders, crabs, corals, starfish

2.
Ans: Animals move to find food and water, escape from their enemies, and return to their shelters. Some animals also migrate to avoid harsh seasons.

3.
Ans: Bones heal quickly because they are richly supplied with blood vessels and nerves, allowing for efficient repair and regeneration of damaged bone tissue.

4.
Ans: The human skull is held together by immovable joints or sutures.

5.
Ans: The human vertebral column is made up of 33 vertebrae.

6.
Ans: The vertebral column (backbone) protects our spinal cord.

7.
Ans: The human rib cage is made up of 12 pairs of ribs.

8.
Ans: The rib cage protects the heart, major blood vessels, and the two lungs.

IV. Differentiate between: 

1.
Ans: Vertebrates:

• Vertebrates have a backbone (vertebral column);
• Examples of vertebrates: Fish, amphibians, birds, mammals.

Invertebrates:

• Invertebrates do not have a backbone.
• Examples of invertebrates: Earthworms, snails, insects, spiders, crabs, corals, starfish.

2.
Ans: Pelvic girdle:

• The pelvic girdle connects the lower limbs (legs) to the vertebral column and supports the body when standing or sitting.

Pectoral girdle:

• The pectoral girdle connects the upper limbs (arms) to the body.

3.
Ans: Ligament:

• Ligament is a strong, flexible tissue that holds bones together at joints.

Cartilage

• Cartilage is a tough, smooth, and flexible tissue that covers the ends of bones at joints, protecting them from wear.

4.
Ans: Movable joint: 

• Movable joints allow for movement and are surrounded by synovial fluid, making the joint surfaces wear-resistant.

Immovable joint of the human skeleton:

• Immovable joints do not allow movement and are found in the human skull where bones are held together by sutures.

V. Answer the following questions in four to six sentences. 

1.
Ans: Birds have several adaptations that enable them to fly. Their skeleton is made up of porous and hollow bones, reducing body weight. Wings covered with feathers provide a large surface area for lift, and tail feathers help maintain balance. The streamlined shape of a bird's body is specifically designed for efficient flight. Birds can fly by flapping their wings or gliding, utilizing their modified body structures for aerial mobility.

2. 
Ans: They slither using a movement called "lateral undulation." Imagine a snake making S-shaped curves as it moves. It pushes against the ground with its muscles, creating waves that travel from its head to its tail. The belly scales help it grip the ground, so it doesn't slip backward. This movement lets snakes smoothly glide and explore their surroundings.

3. 
Ans: The hinge joint is a pivotal type of movable joint crucial for various body movements. Found in the knees, elbows, and fingers, it enables flexion and extension along a single plane, resembling the action of a hinge. Comprising bones with convex and concave surfaces, this joint allows controlled, stable movement while preventing excessive rotation. Synovial fluid lubricates the joint, minimizing friction and ensuring smooth articulation. The hinge joint is essential for activities such as walking, bending, and lifting, highlighting its fundamental role in daily human motion. Its structural simplicity facilitates strength and stability, making it a vital component in the biomechanics of the musculoskeletal system.

Hinge joint

Think and answer

1.
Ans: The little fieldmouse likely uses its limbs, specifically its legs, to move from one place to another. Limbs, such as legs, provide support and help in lifting the body away from the ground, facilitating movement. Fieldmice may use a combination of walking, running, hopping, or crawling to navigate their environment and fulfill their daily activities.

2.
Ans: Uncle Rustam's knee pain may be attributed to aging, and possibly wear and tear of the knee joints. As people age, the cartilage in joints may wear down, leading to discomfort and pain during movement. This is a common issue in elderly individuals, and it may affect the synovial fluid and cartilage in movable joints, making walking painful.

3.
Ans: Cartilage injuries can take a long time to heal because cartilage does not have a direct blood supply, hindering the repair process. When cartilage, which covers the ends of bones at joints, is damaged, it can result in prolonged recovery. Shakeel's left knee injury likely affected the synovial fluid and wear-resistant cartilage, contributing to the extended healing time.

4.
Ans: Tarun's inability to bend his back after a fall may suggest an injury to the vertebral column or surrounding structures. The vertebral column provides support to the body and allows flexibility. If there is trauma to the vertebral column, such as a fracture or injury to the discs between vertebrae, it can restrict movement. In such cases, it is essential to seek medical attention for a proper diagnosis and treatment.