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.

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.

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.

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”.

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].

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.

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

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.

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”.

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

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].

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.

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.

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.