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.

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.

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].

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.

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

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.

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.

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].

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).

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.

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.