(i)It has no bones.
(ii) Rib
(iii)When organism move their body parts without changing their position.
(iv)Cartilage.
(v)Bones are held together at joints by strong cords called ligaments.
(i)the round end of one bone fits into the hollow space of the other bone. Such a kind of joint allows movements in all directions. These types of joints are called ball & socket joint.
(ii)It provides shape to our body
It helps in the movement of body
(iii)A joint that does not allow any movements around it is called fixed joint.
The joints of the skull bones are fixed joints.
(iv)A thick structure and the head of the snail comes out of an opening in the shell of the snake. The thick structure is its foot, made of strong muscles. It helps the snail to move.
(v)Hinge joint is present in the fingers of our hand; it can move only in forward and backward direction. This joint helps us to grab pen in our hand.
(i)It helps us to stand straight.
It protects the spinal cord.
(ii)Earthworms are small worms which can move easily on hard and slippery surfaces. Earthworms move with help of tiny, stiff hair-like projections called bristles. Earthworms move forward by repeated contractions and relaxations of their muscles in the skin. A slimy substance secreted by the earthworm helps in its movement.
(iii)Tissues are groups of cells that have a similar structure and act together to perform a specific function.
(iv)Snakes slither to move around because they have no legs. They rely on their muscles and scales. The scales drag against the ground to help move the snake forward. Snakes move in S-shaped loops and in a zigzag manner. Each loop of the snake gives it a forward push by pressing against the ground. Since its long body makes many loops and each loop gives it this push, the snake moves forward very fast and not in a straight line.
(v)Due to streamlined body water can flow around it easily and allow the fish to move in water.
(vi)Cartilage is a soft tissue attached to bones and is also present independently. Cartilage is much softer than bones.
Firstly, it ensures that the bones move smoothly in the joint.
Secondly, it can cushion and deaden loads, thus preventing bone damage.
(i)If our backbones had fixed joints, we would have not been able to bend our body from our waist.
(ii)The movement of the whole body of an organism from one place to another is called locomotion. The change in the position of any part of the body with respect to its axis is called movement.
(iii)the doctor must have observed swelling & tenderness in the ankle region &have taken a x-ray of the region. With the help of x -ray the doctor must have reached the diagnosis that Ramesh’s ankle was fractured.
(iv)The joint in which the rounded end of one bone fits into the cavity (hollow space) of the other bone is called ball and socket joint.
(v)if we had ball & socket joint between our neck & head then we would have been able to rotate our head 360o
All the bones in our body form a framework to give a shape to our body. This framework is called the skeleton.
There are four types of joint in our body
They are
skull is a bone framework enclosing the brain.
Fixed joints are present in between skull bones
Function of skull are
It is a structure made up of 12 pairs of curved bones that surrounds and protect the chest. Ribs are attached to the sides of each vertebra at back and first 10 pairs are attached to the chest bone (sternum) in the front with the help of cartilage. The last 2 pairs of ribs are free in the front end & are called floating ribs.
Functions: