The point where two or more bones come into contact is called joints. It is present in both humans and animals. Ligaments connect two bones. Tendons hold the bones with the muscle. Some of the different types of joints are as follows: 

1. Fixed Joints
   As the name suggests, fixed joints are the joints that are fixed and have no bone movements concerning body movement. For example, the cranium or skull bones joints are immovable joints. They are also known as linkages. 

2. Moveable Joints
   Moveable joints are the joints that move with the movement in the bones. The moveable joints are categorised into two versions, freely moveable joints, and partially moveable points. However, four types of joints are moveable in the human body.

3. Pivot Joints
   Pivot joints allow you to have movement across your body, like up and down, side to side, etc. The joint located between the vertebral column and the skull is known as the pivot joint. It allows you to move your body side to side or hands up and down. 

4. Ball and socket Joint
   Ball and socket joints have rounded ends that allow one bone to fit into the vacant space of another bone. The ball and socket joints allow you to make movements in all directions. Another example is the joint between thigh and hip. It helps an individual to make movements in every direction as required. 

5. Hinge Joint
   The hinge joints are similar to the door hinges. It allows you to move across a single plane. The example of the hinge joint includes the knee and elbow.  

6. Gliding Joint
   Gliding joints help with the movement of sliding the bones to one another. The joints between the backbone rings are examples of gliding joints.

The movement in the other organisms such as birds, fish, snails, and earthworms are as follows: 

1. Earthworm
   The earthworm’s body is made up of various rings that are connected with each other end to end. There are no bones present in the body of an earthworm. The muscle of the earthworm is the main reason that causes shorten actions and spread. The body of the earthworm discharges a substance similar to slimy that helps in the movement of the earthworm. It also holds a huge number of tiny bristles. Each bristle of the earthworm is connected to the muscle that helps to manage a good grip while crawling on the ground. 

2. Snail
   Snails crawl on the ground and have a rounded structure in the back. The shell of the snail and the outer skeleton of the organism is not made up of bones. You can count it as a single unit. It has no part in the movement of the entire body of a snail. The snail moves with the help of its muscular foot and crawls on the floor. 

3. Birds
   The bones are present in the birds. Birds have strong muscles and light bones, and both things work well together to develop the movement when a bird flies. A bird flies using its wings. The muscles help them in flapping their wings and fly higher. 

4. Fish
   The head and tail of the fish is smaller compared to the middle portion. This type of body shape is known as streamlined. Therefore, the shape of the fish allows it to flow with the water easily. This further allows fish to gain motion while moving in the water. 

1. Fill in the blanks: 

1. The bone joints help a living being with the _______ of the body.
2. The bones present in the elbow are joined by ________. 
3. A combination of cartilages and bones forms _______.
   
   

Solution:

1. Movement 
2. Hinge 
3. Skeleton
   
   

2. What do you mean by the ball and socket joint? Explain. 

Ball and socket joints have rounded ends that allow one bone to fit into the vacant space of another bone. The ball and socket joints allow you to make movements in all directions. Another example is the joint between thigh and hip. It helps an individual to make movements in the direction as required. 

3. What are fixed joints?

The fixed joints, as the name suggests are the joints that are fixed and have no bone movements with respect to any body movement. For example, the joints present in the cranium or skull bones are immovable joints. They are also known as linkages. 

4. Explain the movement of snails. 

Snails crawl on the ground and have a rounded structure in the back. The shell of the snail and the outer skeleton of the organism is not made up of bones. You can count it as a single unit. It has no part in the movement of the entire body of a snail. A snail moves with the help of their muscular foot and crawls on the floor.

Frequently Asked Questions on NCERT Solutions for Class 6 Science Chapter 8

1. Is the Chapter 8 Body Movements important for the Class 6 Science examination? 

Chapter 8 Body movement is essential for the examination point of view as it carries 18 marks as a whole. The chapter comes in Unit 4 and contributes 16% of the marks in the examination. So, students are advised to practice the chapter thoroughly to get good grades. 

2. What topics are essential for Chapter 8 of NCERT Solutions? 

The important topics are as follows: 

• Human body and its movements 
• Ball and socket joints 
• Pivotal Joint 
• Hinge joints 
• Fixed joints 
• Gait of animals 

3. What are the uses to learn from the NCERT Solutions for Chapter 8 Science? 

The uses are as follows:

• All the questions have answers in a detailed manner. 
• Students can download the PDF file for easy access to NCERT Solutions. 
• Diagrams are present in the solutions to understand the topics easily.