Class 6 Science Chapter 5 MCQ

Snakes do not have legs, even then they move quite fast because a snake moves forward by moving its body sideways in the form of many loops and pushing against the ground.

When the fish’s tail moves side to side, it pushes the water sideways as well as back-wards. The backward push of tail on water, makes the fish move forward.

In birds, the backward movement of wings pushes the air in backward direction. This air pushes the wings in the forward direction and makes the bird move forward. Thus, during the downstroke of wings, the air is pushed downward and backwards. The equal and opposite reaction force of air pushes the bird up and forward, and makes it fly.

Here, all the statements are correct. Hence, your answer will be option [D].

Snail is a very slow-moving animal with a shell on its back. The foot of snail is large, flat and disc-shaped which is made of strong muscles. It is called muscular food. Snails are gastropods which means belly-footed animals. The movement of snail is called “creeping”.

Here, all the statements are correct. Hence, your answer will be option [D].

The plate type bones of our skull are held together by fixed joints and cannot move at all.

In the human body the upper arm consists of a single bone called humerus. The lower arm or forearm is from elbow to wrist. The lower arm or forearm is made up of two bones radius and ulna. The upper arm bone is connected to the lower arm bones by a hinge joint at the elbow.

The knee joint is an example of hinge joint. At the knee, the lower end of upper leg bone is in the form of a knob and the upper end of the lower leg bones is in the form of a cup. The knob of upper leg bone fits into the cup of lower leg bone to form a hinge joint at the knee. The ligaments hold the upper leg bone and lower leg bones together at the knee joint.

Shoulder joint and hip joint are the examples of ball and socket joints. In the ball and socket joint, one end of the bone has a round shaped like a ball which fits into a socket in the other bone. A ball and socket joint allows much more movement of bones than any other joints found in the human body.

Snail is a very slow moving animal with a shell on its back. The foot of snail is large, flat and disc-shaped which is made of strong muscles. It is called muscular food.

The human body has two shoulders, one on each side of the neck as collarbone and shoulder blade. The collar bone is a long, curved bone and the shoulder blade is a large and flat triangular bone.

The shoulder blade is attached to the backbone by muscles to allow the free movement of the shoulder. Each shoulder blade has a cup shaped socket. The upper arm fits into the socket of shoulder blade forming ball and socket joints.

The bony framework inside our body is called a skeleton. In human beings, the skeleton is inside the body, so it is called an endoskeleton. Actually, our body is supported on a hard framework of bones. We can stand straight because of the “Internal skeleton”.

The lower arm is made up of two bones as radius and ulna.

Here, all the statements are correct. Hence, your answer will be option [D].

Here, all the statements are correct. Hence, your answer will be option [D].

Birds can fly because their bodies are adapted or modified for flying purposes. As their flight feathers provide a large flat surface which is light but strong. Their bones are hollow and light. And their bodies are streamline and extremely light. Birds have breast bone which is extended for the attachment of large flight muscles (which moves the wings up and down).

If we open and close a door, we will find that the door can move only “forwards” and “backwards”. Actually, the door is joined to its frame by a small metal “joints” called “hinge”. These hinges allow the door to move only in one direction, “forwards and backwards”. We can move the lower jaw because the lower jaw is connected to the skull by a movable joint called hinge joint. The hinge joint in lower jaw allows the chewing of food.

Snake moves forward by moving its body sideways in the form of many loops, and pushing against the ground. The special name of the wave like motion of the snake is called “slither”. And also remember, snake does not move in a straight line because the sideways pushes of the loops push the snake forward as well as sideways.

When we want to bend the arm, the bicep muscles contracts means it become shorter and fatter. The contraction of biceps muscle pulls the lower arm bones due to which the lower arm moves up or bends. Biceps muscles is called flexor muscle because it flexes (bends) the arm.

Snail moves with the help of a large, disc-shaped muscular foot. The whole body of a snail is soft and consists of a head, a foot and a shell. Shell is the outer structure (skeleton) of a snail, but it is not made of bones.

The fin-like flippers worn by underwater divers help to swim easily in water. It mainly helps to keep the balance of the body and to keep direction, while swimming (just as fins in fishes).

Snail does not have both muscles and skeleton for movement. The shell serves for muscles attachment and protection. The movement is carried out only with the help of large disc-shaped muscular foot that has two sets of muscles. In earthworm, a hydrostatic skeleton (fluid filled cavity surrounded by muscles) is present. The alternate contraction and relaxation of muscles and pressure of the fluid helps in burrowing. Dog and human beings have Musculo-skeletal system for movement.

Our bones and muscles together form the musculoskeletal system that enables the movement of body parts and the whole body from one place to another.