Class 6 Science Chapter 5 MCQ

Generally, in human body radius, ulna, humerus are found in arm but femur is found in thigh or upper leg.

Hinge Joint allows the movement of bones in only one direction forward and backwards. In a hinge joint, the movement of bones is restricted to one direction by the shape of the ends of the bones which form the joint. Elbow, knee, knuckles (finger joints) and jaw are examples of hinge joints. And knee joint is also a hinge joint. But shoulder joint is an example of ball and socket joint.

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.

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.

Cartilage is also found on the ends of bones where they meet one another at a joint. Cartilage is also present between the vertebrae of backbone as cartilage disc.

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

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

There are 206 bones in the human skeleton or human body.

Our skeleton consists of hard bones. However, at some places in the skeleton, there is a material which is not as hard as bones and which can be bent easily. That is called cartilage. Cartilage is a kind of softer and elastic bone which is present in nose, ear and the end of bones where they meet one another at a joint.

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

The pivot joint allows rotation around an axis. A pivot joint exist between our skull and the top vertebra of backbone. Another pivot joint occurs in the forearm or lower arm near the elbow. The pivot joint in the forearm make us turn our forearm to hold the palm of hand up or down.

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).

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

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.

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.

Upper jaw and skull joints are immovable or fixed. Bones are held, so tightly together that they cannot move at all. The other options are: Shoulder and Arm is ball and socket joint, Knee and Joint is hinge joint, Lower jaw and Upper jaw is hinge joint.

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.