I. Multiple Choice Questions (MCQs).
Q.1. The movement of an organism, from one place to another is called
d) none of these
Answer: b) locomotion
Q.2. Bones are joined together to form a
d) none of these
Answer: c) skeleton
Q.3. The longest bone of the body is
d) none of these
Answer: a) femur
Q.4. The bones are held together at the joints by strong, stretchy bands called
d) none of these
Q.5. Muscles are attached to the bones by means of tough bands called
d) none of these
Answer: a) tendons
II. Fill in the blanks by selecting appropriate words from the given list :
List : three, Skeleton, liquid, 300, skull
Q.1. _______________ protects delicate organs of the body, gives shape to the body and helps in well defined and planned movement.
Q.2. The _______________ is the bony framework of the head.
Q.3. A new born baby has more than _______________ bones.
Q.4. Worms have _______________ skeleton.
Q.5. The body of cockroach is divided into _______________ parts.
Answer: 1- Skeleton,
III. Match the items of Column A with those of Column B.
Ans- 1-c, 2-d, 3-b, 4-e, 5-a
IV. Write ‘T’ for the true and ‘F’ for the false statements.
Q.1. Movements in animals helps them to move towards safety and to such places where food and water are available.
Q.2. Bones are white, strong and hard pieces made of mainly phosphorus.
Q.3. The lower leg of human body is made up of two bones—tibia and fibula.
Q.4. The skeleton present inside the body, is known as endoskeleton, such as skeleton of humans and birds.
Q.5. The skeleton of the fish is covered with weak muscles.
Answer- 1-T, 2-F, 3-T, 4-T, 5-F
V. Very Short Answer Questions.
Q.1. Define skeleton.
Answer: The skeleton is the body part that forms the supporting structure of an organism.
Q.2. What do you mean by joints?
Answer: Joints are places, where two or more bones meet.
Q.3. Write two examples of hinge joint.
Answer: Knee and the elbow are the example of hinge joint.
Q.4. Mention two animals, which possess exoskeleton.
Answer: Crab and cockroach
Q.5. Write three parts of the body of cockroach.
Answer: body of cockroach is divided into three segments: head, thorax and abdomen.
VI. Short Answer Questions.
Q.1. Write the importance of skeleton in human body.
Answer: A skeleton protects delicate organs of the body, gives shape and helps in well defined and planned movement.
Q.2. How are joints useful for our body?
Answer: There are three major type of joints present in our body. These are 1) Fixed joints: Main function of fixed joints is to provide protection.
2) Slightly movable joint : Main function of Slightly movable joints is to provide support.
Freely movable joints: Freely Movable joints joints allow free movements in various direction. Most of the joints in the body are freely movable.
Q.3. How do bones move?
Answer: Muscles, attached to the bones, make them move at the joints. Muscles are like elastic bands. They are attached to the bones by means of tough bands called tendons. Muscles move the bones by their pull. Muscles cannot push. Therefore, to move the bones in one direction at least two sets of muscles are required. For examples, the up and down movements of your arm are controlled by two muscles — biceps, and triceps. When you want to raise your arms, the biceps in front contract, i.e., they become shorter and fatter to pull up the arm.
Q.4. What do you mean by axial skeletal system? Where are these found in the human body? Explain with example.
Answer: The axial skeleton is the part of the skeleton that consists of bones of skull, vertebral column and chest bone.
• Skull is found in the head.
• Vertebral column found superiorly and inferiorly at the junction of the body and pedicle.
• Chest bones are found in the front part of the body.
Q.5. Write the different types of skeletons in animals. Explain with examples in brief. Answer: Animals have different types of skeletons.
(a) Liquid skeleton : Worms have this type (liquid) of skeleton. Liquid is trapped in spaces inside the body. The muscles squeeze against the liquid. This keeps the body firm.
(b) Exoskeleton : The skeleton present outside the body, is called exoskeleton. Exoskeleton gives protection, support and also allows movement at the joints, such as in crab and cockroach.
(c) Endoskeleton : The skeleton present inside the body, is known as endoskeleton, such as skeleton of human and birds.
Q.6. What do you mean by locomotion in earthworm? Discuss briefly.
Answer: The body of an earthworm is made up of many rings joined end to end. They do not have bones. It has muscles which help to extend and shorten the body. The shape of earthworm is maintained by the fluid present inside its body. It has liquid skeleton. During movement, the earthworm first extends the front part of the body, keeping the rear portion fixed to the ground. Then it fixes the front end and releases the rear end. It then shortens the body and pulls the rear end forward. This makes it move forward by a small distance.
VII. Long Answer Questions.
Q.1. What do you mean by appendicular skeletal system? Discuss with proper examples.
Answer: Appendicular skeletal system consists of two pairs of girdles and bones of arms and legs.
Girdles : The bones that are found in the shoulder form the pectoral girdle. It protects the heart and lungs. It also provides attachment for the upper arm.
Bones of arms : In the upper arm, there is only one bone, humerus. It exactly fits into the cavity in the pectoral girdle. On the lower side, it has a broad surface which is connected to two bones, radius and ulna of the lower arm.
Bones of legs : The bone present in the thigh, femur is the longest bone of the body. It has a ball shaped head that can be fitted into a cavity formed by pelvic girdle. The lower end joins the lower part of the leg. The lower leg is made up of two bones – tibia and fibula.
Q.2. Write the different types of joints in human body, depending upon type of movement. Explain them with proper examples.
Answer: There are four types of joints, depending upon the type of movement they allow —
1. Hinge joint
Joints at the knee, fingers and the elbow are examples of this type of joint. This joint allows movement in one direction only upto 180°.
2. Ball and Socket joint
In this type of joint, the ball-like surface of one bone fits into a cup-like hollow in the other. It allows the movement in all directions. Joint at the hip and the shoulder are examples of this type of joint.
3. Pivot joint :In this type of joint the rounded surface of one bone fits into a ring formed by the other bone. One of the bones is able to rotate over the other. This type of joint is found between the first two vertebrae of the backbone.
4. Gliding joint : The wrist or ankle joints have flattened ends of bones that can move (or glide) against each other. These joints allow side to side as well as backward and forward movement.
Q.3. Write brief notes on
(a) Locomotion in cockroach (b) Locomotion in birds (c) Locomotion in fish
(a) Locomotion in Cockroach
It is also an invertebrate. Its body is divided into three parts namely, head, thorax and abdomen. It has three pairs of legs and two pairs of wings which help in movement. They have distinct muscles – those near the legs help in walking. The breast muscles move the wings when the cockroach flies in the air.
(b) Locomotion in birds Birds can fly in the air and walk on the ground. Some birds like ducks and swans also swim in water. Most birds are capable of flying. The following features help them to fly:
i. They have streamlined body, which makes it easier to move through air.
ii. Their bones are hollow, which makes them light weight.
iii. They have strong but light wings, which are equipped with feathers.
iv. They have powerful chest muscles, which help them in flapping their wings during flight.
(c ) The skeleton of the fish is covered with strong muscles. During swimming, muscles make the front part of the body curve to one side and the tail part swings towards the opposite side. Then, quickly, the body and tail curve to the other side. This makes a jerk and pushes the body forward. A series of such jerks make the fish swim ahead. This is helped by the fins of the tail. To help movement in water, fishes have a streamlined shape, which reduces the water resistance and enables the fish to glide along in the water.