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Science, , Amrutha Varshini Vidyalaya, , 6th Std, , 8. Body Movements, , Answer the following, , 1., , A:, , >yY >PR, , What is a ball and socket joint ?, , The rounded end of one bone fits into the, bone. This is called ball and socket joint., allow movements in all the direction, , s, e.g. shoulder and hip, , can be moved in all directions., , Which of the skull bones are movable?, In skull, only lower jaw is movable., , Why can our elbow not move backwards?, , Our elbow cannot move, , backwards because the elbow has a, , hinge joint that allows movement in only one direction., , Explai, , n various kinds of joints found in our body and give, , example of each., There are five types of joints in our body:, , ii), , iii), , Fixed joints: Those joints which do not allow movement are, called fixed joint. Ex : Skull, Ball and socket joint: This joint allows movement in all, directions. The rounded end of one bone fits into the hollow, space of other bone. For example, joint between upper arm, and shoulder., Pivotal joint: This type of joint allow movement in all, planes, i.e. up and down, side and other planes. For, example, heaa., Hinge joint: The joi ., , ines pote The joint which allows movement only in one, p is called hinge joint. For e, Gliding joint: These joi Rail, Shae ae: Biles, , : se joints allow only a limited amount of, , movement of sliding nature of carti Fi, oer cartilage. For example, the, , hollow space of other, Ball and socket joints, , Stas

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7., , i), ii), , ill), , se, , 10,, , A:, , § eesee’¢ framework is called skeleton., , Jow does the snail move ?, , as yond structure on the back of the snail is called shell. Itis, , I ' er skelcton (exoskeleton) of snail. When it starts movi, , hc ov -tructure and the head of the snail may come out of a, "the shell. The thick structure is called foot, which is, , up of strong muscles. It helps snail in moving., , How does fish move in water ? ., , The body of fish Is streamlined. The streamlined shape helps the, fish to MOVE in water. The skeleton of 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 water., , e differences between bones and cartilage., , write th, Bone Cartilage, They are hard. i) They are soft., , ii) They can bend., iii) They help to make, some parts of the body., , They cannot bend., They are used to make, the framework of whole body., , How is a bird’s body adapted for flying ?, i) Bones are hollow., , ii) Forelimbs are modified into wings., , iii) Body is streamlined., , How does the snake move ?, , Snakes have along backbone and many thin muscles which help, , in the movement. The snake’s body curves into many loops. Each, , a of the snake gives it a forward push by Pressing against the, ound., , Ww C, hat is skeleton? Draw a diagram to show the human, Skeleton,, , Th ; ., ihe in our body form a framework to give a shape to the