Class 6 Science Chapter 5 MCQ

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.

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

Snail have two sets of muscles in the foot of snail which contract and expand alternately, producing a kind of wave effect.

Snails are “gastropods” which means “belly-footed animals”. The movement of snail is called creeping. In a way, the movement of a snail is similar to that of an earthworm.

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.

The rib cage protects the delicate internal organs like heart, lungs and liver. Brain is protected by skull.

Femur, or thighbone, is the largest bone in our body. The head of our femur fits into our hip socket and the bottom end connects to our knee.

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.

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

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

Backbone is made up of 33 small bones placed one over the other.

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).

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.

Snails are “gastropods” which means “belly footed animals”. The movement of snail is called creeping. Remember, an earthworm, however, moves much faster than a snail.

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.

Two muscles (a pair) work together to move a bone. When one muscles of the pair contracts, then the other muscles of the pair is relaxed. The alternate contraction and stretching brings about the movement.

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).

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