Class 6 Science Chapter 8 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.

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

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.

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.

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

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

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].

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

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].

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.

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.

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.