Body Movements

Q34. What does the skull do in the human body?

Ans. Function of skull

                           i.        It encloses and protects a very important part of the body, the brain.

                          ii.        It supports the structures of the face.

Q35. Write two function of skeleton.

Ans. Function of skeleton

                          i.        It helps in the movement of the body.

                          ii.        It provides shape to our body.

Q36. List two functions of backbone.

Ans. Functions of backbone

                          i.        It protects the spinal cord.

                         ii.        It helps us to stand straight.

Q37. What type of skeleton do snails have? Is the movement of a snail fast or slow as compared to an earthworm?

Ans. Snails have a hard shell on their back which serves as the skeleton. Movement of snail is slower than earthworm.

Q38. How does streamlined body help fish to swim in water?

Ans. Due to streamlined body water can flow around it easily and allow the fish to move in water.

 
Q39. What is a fixed joint? Give one example of fixed joint.

Ans. Joint that does not allow any movement is called fixed joint.

Example: Joint between the upper jaw and the rest of the head is a fixed joint.

Q40. How does a snail move?

Ans. A thick structure and the head of the snail may come out of an opening in the shell. The thick structure is its foot, made of strong muscles. It helps the snail to move.

 
Q41. Why are earthworms known as farmer’s best friend?

Ans. The earthworm, actually, eats its way through the soil. Its body then throws away the undigested part of the material that it eats. This activity of an earthworm makes the soil more useful for plants.

Q42. How do we know the shapes of the different bones in our body?

Ans. We can have some idea about the shape and number of bones in some parts of our body by feeling them. One way we could know this shape better would be to look at X-ray images of the human body.

Q43. What is hinge joint? Give one example of hinge joint.

Ans. Hinge joint is a joint in the bones that allows bone movement in only one direction.

Example: The elbow has a hinge joint that allows only a back and forth movement.

Q44. What is ball and socket joint? Give 2 examples of ball and socket joints.

Ans. The ball and socket joint is type of joint in which the rounded end of one bone fits into the cavity (hollow space) of the other bone. Such a joint allows movements in all directions.

Examples: Joint of arm and shoulder

                Joint of thigh and hip

Q45. Bones are hard structures and cannot be bent. But, we still bend our elbow, knee, etc. How is this possible?

Ans. Elbow and knee are made up of two or more bones which are joined together. Our bones, muscles, and joints — along with tendons, ligaments, and cartilage enable us to bend our elbow, knee, etc.

Q46. What is pivotal joint? Give one example of pivotal joint.

Ans. In a pivotal joint a cylindrical bone rotates in a ring. It allows bending forward and backward and turns to right or left.

Example: The joint where our neck joins the head is a pivotal joint. 

 
Q47. What are the four different types of joints?

Ans. Types of joints

                          i.        Ball and socket joints

                        ii.        Pivotal Joint

                       iii.        Hinge joints

                       iv.        Fixed joints