BODY MOVEMENT

Body Movements



Skeletal System

  1. Bones in our body form the framework that supports the whole body. This framework is called the skeleton.
  2. Our skeleton is made up of many pieces of bones and cartilages.
  3. There are about 650 muscles attached to the various bones in our body.
  4. The bones are hard.
  5. Cartilages are comparatively soft and elastic.
  6. Functions of skeleton
  • Skeleton system gives support to the body.
  • It protects the inner organs.
  • Together with muscles, it gives the body its shape.
  • Red blood cells and some white blood cells are produced in the marrow of the bone.


7. X-ray machine : We can get photographs of bones by a machine called X-ray machine. Doctors use these photographs to examine the injuries and diseases of bones.

8. The bones in our body vary in their sizes and shapes. Different types of bones have different functions.

9.The skull :
The skull has two main parts :

  • Cranium : The bones of cranium are flat. They are held firmly like a zipper, it covers and protects the brain.
  • Facial bones : The facial bones comprise the upper jaw, lower jaw and few other bones. The lower jaw is movable. The movement of lower jaw enables us to eat, talk and sing.

10. Eye sockets : The skull also includes a pair of eye sockets. These form a safe pocket for eyes.

11. The backbone :
Backbone or vertebral column is composed of 33 small, ring like vertebrae joined end to end. It forms a hollow bony tube. The main nerve cord passes through it. 

12. The chest bones : 12 pairs of ribs along with backbone make a cone shaped cage which protect the heart. 

13. The shoulder bones :
The shoulder bone is formed by the color bone and the shoulder blade. The shoulder bones are flat and large. They help in forming joint with long bones.

14. Hip bones :
The hip bone is formed by the fusion of three bones. Like shoulder bones, the hip bones are also flat and large. They help in forming joints with long bones. Together with the last two parts of backbone it forms a large bony bowl called pelvis.
 
15. Bones of hands and legs : Bones of arms, thighs etc., are long. They give strength to our body. Bones of fingers and toes are short. They help us in holding things. The hands and legs are constructed in same pattern as described below.
 
 
 
 
 
 
 

 
Parts of HandPart of Leg

No. of Bones

Upper arm
 
Fore arm
 
Wrist
 
Palm
 
Fingers

Thigh
 
Lower leg
 
Ankle
 
Foot
 
Toe
One long bone
 
Two long bones
 
Several small bones
 
Five bones
 
Each has three small bones

 
16. Bone joints : The place where two or more bones meet together is called a joint. In our body five types of joints are present namely :
  • Fixed joints which do not allow movement, e.g. joints of cranium.
  • Ball and socket joint allows movement in all direction e.g. joints between upper arm and shoulder, thigh and hip.
  • Pivotal joint allows movement in many planes e.g. skull makes such joint with first two vertebrae.
  • Hinge joints allow movements only in one direction e.g. fingers, the knee etc.
  • Gliding joints allow only a limited amount of movement e.g. joints of backbone.
 
 
17. Muscles : The bones are moved by alternate contractions and relaxations of two sets of muscles.

18. Tendons
join muscles to the bones.

19. Ligament
joins two bones.

20. Bristles :
Bristles are hair like structure, connected with muscles. The bristles help to get a good grip on the ground.

21. Cavity :
It is the hollow space in one bone, into which the other bone fits. Such joint allows movements in all directions.

22. Gait of animals :
Some animals do not have bones. They have muscles which help to extend and shorten the body. During movement, animal first extends the front part of the body, keeping the rear position fixed to the ground. After that animal fixes the front and releases the rear end. Now animal shortens the body and pull the rear end forward. During this practice animal move forward by a small distance.

23. Rib cage :
Ribs join the chest bone and the backbone together to form a box. This is called rib cage.

24. Locomotion


There are two kinds of movements :
  1. The organisms move their body parts without changing their position.
  2. Animals move from place to place. This kind of movement is called locomotion.

            Locomotion in some Animals

  1. Birds
  • Most of the birds have two kinds of locomotion. They walk with legs on the ground. They also fly in the air. Ducks and swans also swim in water.
  • Flying adaptations : Streamlined body, bones with air spaces, forelimbs modifies into wings, air sacs connected to lungs and massive flight muscles are some adaptations in birds for flying.

       2. Fish : The fishes swim by forming loops alternately on two sides of the body. The tail pushes them forward. The vertebrae and the muscles attached to them work for it.
       3. Snakes :Similarly the snakes crawl on the ground by alternately looping sideways. A large number of vertebrae and associated muscles push the body forward. The ventral scales also help in the process.
       4. Insects :The body and legs of insects have hard jointed coverings, forming an exoskeleton. The muscles of the breast connected with three pairs of legs and two pairs of wings help the cockroach to walk and fly.
       5. Snails :The snails are moved by the muscular foot. The hard unjointed shell have no relation with the foot.
      6.Earthworm :
The earthworm move by alternate extension and contraction of the body effected by the muscles. The minute movable bristle help in gripping the ground. 

Q.1. Fill in the blanks :

  1. Joints of the bones help in the ………… of the body.
  2. A combination of bones and cartilages forms the ……….. of the body.
  3. The bones at the elbow are joined by a …………. Joint.
  4. The contraction of the ………… pulls the bones during movement.
Ans. (a) movement     (b) skeleton      (c) elbow           (d) muscle.

Q.2. Indicate True (T) and False (F) among the following sentences :
  1. The movement and locomotion of all animals is exactly the same.              (  )
  2. The cartilages are harder than bones.                                                          (  )
  3. The finger bones do not have joints.                                                             (  )
  4. The fore arm has two bones.                                                                         (  )
  5. Cockroaches have an outer skeleton.                                                           (  )
Ans. (a)  F        (b)  F      (c)  F          (d)  T          (e)  T.
 
 
 
 
 
Q.3. Match the items in Column I with one or more items in Column II.
Column IColumn II

i. Upper jaw
 
ii. Fish

iii. Ribs

iv. Snail

v. Cockroac

a. have fins on the body

b. has an outer skeleton

c. can fly in the air

d.  is an immovable joint

e.  protect the heart

f. shows very slow movement

g. have a streamlined body

 
Ans. (i)  (d)        (ii)  (a)          (iii)  (e)          (iv)  (b)        (v)  (c).

Q.4. Answer the following :
  1. What is a ball and socket joint?
  2. Which of the skull bones are movable?
  3. Why can our elbow not move backwards?
Ans. (a) The rounded end of one bone fits into the hollow space of the other bone, such kind of joints is called ball and socket joints. Ball and socket joints allow movements in all directions.
(b) In skull only lower jaw is movable.
(c) Our elbow can not move backwards, because the elbow has a hinge joint that allows movement in one direction only.
 
 
 
 
 

ADDITIONAL IMPORTANT QUESTIONS

Q.1. At which point does the arm rotate?

Ans.
The arm rotates on the round pit like structure.

Q.2. Which is the longest bone in your body? Measure it with your scale.

Ans.
Femur is the longest bone in our body. It is a thigh bone.

Q.3. Name the bones which protect the heart from all sides.

Ans.
Breastbone from front and the backbone at the back makes a type of box to protect the heart.

Q.4. Does the shoulder bone also move when you move your arm?

Ans. The shoulder bone does not move when we move our arm. Only arm moves, the shoulder bone remains fixed.

Q.5. Why can’t an earthworm stand up straight like us?

Ans. An earthworm can’t stand up straight like us because it has no skeleton. An earthworm is like a leech. It swims in the water and its muscles help it to move.

Q.6. Keeping your arm straight, move it forwards and backwards, up and down. Can the arm move freely in all directions?

Ans.
Yes, the arm can move forward, backward down and up.

Q.7. Do the bones of the upper jaw move?

Ans. The bones of the upper jaw are joined with fixed joints. So they do not move.

Q.6. Keeping your arm straight, move it forwards and backwards, up and down. Can the arm move freely in all directions?

Ans. Yes, the arm can move forward, backward down and up.

Q.7. Do the bones of the upper jaw move?

Ans. The bones of the upper jaw are joined with fixed joints. So they do not move.

Q.8. Why do animals move from one place to otherA?

Ans. Animals move from one place to other:

       (i) To obtain their food and shelter.
      
       (ii) To protect themselves from enemies and unfavourable climate.


Q.9. Name various parts of skeletal system.

Ans. The skeletal system can be divided into following main parts :
  1.  Skull                  (2)  Back bone                    (3)  Limb bones
     (4)  Chest bones      (5)  Shoulder bones            (6)  Hip bones.

Q.10. Name the organs of locomotion of

          (a) Man                        (b) Bird                       (c) Fish.

Ans.
(a) Man – Legs
         (b) Birds - Wings
         (c) Fish – Fins.

Q.11. What is cartilage? Give one example.

Ans. These are some additional parts of the skeleton that are not as hard as the bones and which can be bent. For example, the upper part of our ear has cartilage.
 
Q.12. Which important organ is fully protected inside the bones of the skull (head)?

Ans. The bones of the skull form the structure similar to a box. The bones are joined with strong joints. It is not easy to break them. The bones of the skull protect the most important organ i.e. the brain.

Q.13. Do the bones on top of the skull move?

Ans. The bones on top of the skull form the structure similar to the structure of teeth. They are joined strongly with one another. So these bones are also fixed. These bones do not move.

Q.14. Try to eat your food without moving the lower jaw. Do you find this difficult to do?


Ans.
Without moving the lower jaw, we cannot chew the food. Without chewing we cannot engulp the food into food pipe. It would be difficult to digest unchewed food.

Q.15. What is the function of skeleton?

Ans. Skeleton : (a) It forms the framework of body.
         (b) It gives shape and structure to the body.
         (c) It protects the internal organs.
         (d) It helps in the movement and keeping body erect.
         (e) Ribs of chest help in breathing.

Q.16. Draw a labeled diagram of a ball and socket joint.

Ans.

 
Q.17. What is exoskeleton? Explain giving examples.

Ans.
The bodies of crabs, insects and spiders are covered and protected by hard coverings. These hard parts outside are called exoskeleton (ekso-skel-e-ton). Nails and hair are also exoskeleton found in our body. Similarly the scales of cockroach, fish, outer shell of snails and oyster are also exoskeleton of these animals.

Q.18. Identify and label the different bones in the skeleton shown in the figure.

 
Q.19. What is a bone joint? Describe various kinds of joints found in our body.

Ans. Joints : The place where two or more bones meet together is called a joint. There are five main types of joints in our body.
(i) Fixed joints : Some attachments do not allow movement. They are fixed joints. Joint of the cranium is a fixed joint. (Fig. 8.12)
 
(ii) Ball and socket joints : The rounded end of one bone fits into the hollow space of the other bone. (Fig. 8.13). Such a kind of joint allows movements in all directions and is called ball and socket joint. Example : the joint between the upper arm and the shoulder; the thigh and the hip.
 
(iii) Pivotal joints : The skull is joined to the first two vertebrae of the backbone like a ball to a stick. This type of joints allow movements in many planes – up and down, to the side and all other planes.
(iv) Hinge joints : These joints allow movement only in one plane like a door hinges and not more than 180 degrees. Example : the fingers; the knee. The wrist is a double hinge joint (Fig. 8.14).
 
(v) Gliding joints : These joints allow only a limited amount of movement of sliding nature of cartilages (Fig. 8.15), for example, the joints in backbone.
 
Q.20. Write short notes on the following:
(a) Skull             (b) Chest bones              (c) Backbone
(d) Hip bone      (e) The shoulder bones  (f) Limb bones

Ans.

  1. The skull : The (SKULL) has two main parts. They are the cranium (cra-ni-um) or the brain case and the facial bones. The bones of the cranium are flat. They are held firmly like a Zipper. The cranium covers and protects the brain. The facial bones comprise the upper and lower jaws and a few other bones. The lower jaw is movable. The movement of the lower jaw enables us to eat, talk, and sing. The skull also includes a pair of eye sockets. These form a safe pocket for the eye.
  2. The chest bones :The chest is a cone shaped cage (Fig. 8.16). It encloses the heart and the lungs. At the back are the vertebrae, 12 pairs of ribs curve round the sides. Ribs are attached to the sides of each vertebrae. Ten of them are also attached by cartilage to the breast bone at the front. Two ribs are free. These are called floating ribs.
          
          The ribs are joined in such a way that they allow the necessary movement of the chest during breathing.
  1. Backbone : Vertebral column or bone is composed of 33 small, ring-like vertebrae joined end on end. Thus it forms a hollow bony tube. The main nerve cord passes through it. The backbone has five regions from top to bottom they are the neck, chest, belly, hip and tail. Five vertebrae of the hip and four vertebrae of tail are fused (Fig. 8.2).
  2. Hip bone :The hip bone is formed by the fusion of three bones (Fig. 8.5). The hip bones together with the last two parts of the backbone from a large bony bowl. It is called the pelvis (pel-vis). It is the lowest and strongest part on which we sit on. The thigh bones are attached to the hip bones.
  3. The shoulder bones :The shoulder bone is formed by the collar bone and the shoulder blades (Fig. 8.4). It connects the upper part of the chest and the bones of the hand.
The bones of the upper arm attaches with the shoulder bones.
  1. Limb bones : The hand comprises the upper arm, fore arm, wrist, palm and fingers. The leg includes the thigh, lower leg, ankle, feet, and the toes. The bones in hand and leg are in same pattern and called limb bones, upper and thigh has one long bone. The thigh bone is strongest and longest bone in the body. In the fore arm and lower leg, there are two long bones. Wrist and ankle are made up of several small bones. Palm and foot have five longer bones. Each finger and toe is made up of three small bones.
Q.21. How can we get photograph of a bone? What is the use of such photographs?

Ans.
We can get photograph of a bone by a machine called X-ray machine. Doctors use these photographs to examine the dislocations and fractures in the bone.
 
Q.22. Why bones in the foot are normally set in an arch? What is a flat foot?

Ans. The bones in the foot are normally set in an arch (Fig. 8.18). The feet arches give good support to the body. They also bend and spring back each time one steps out. The smaller toe bones also help in walking and running. In some cases the foot is flat instead of being arched and are called flat-foot. Not all flat feet cause trouble, but sometimes they give trouble or cause pain. Then it may need special care.
 
Q.23. How incorrect sitting postures harm us? What are the correct sitting and standing postures?

Ans. Incorrect sitting postures cause stresses and strains on the muscles and bones. [Fig. 8.19 (a)]. It may fatigue and painful.
In correct position, one should sit straight and relaxed. One should not bend in front or lean backwards. [Fig. 8.19 (b)]. The fore arms should be at the same level. The feet should rest flat on the floor. The lower leg should be erect making a right angle at the knee.
Similarly, one should stand straight and erect and not drooping in front for a long time. [Fig. 8.19 (c) ]. The habit should be checked from childhood when the bones are soft. Otherwise the curvature or bent of the backbone may become permanent with age as the bones gradually harden.
 
Q.24. Do all animals have bones?

Ans. No, all animals do not have bones. Bones are present only in the backboned animals. Even among the backboned animals, the skeleton of sharks are made entirely of cartilage.

The jelly fish, leeches and worms have no hard structure to support their bodies.

Q.25. What is dislocation and fracture of a bone? What precaution should we take when one gets a fracture?

Ans. Dislocation and fracture : Any careless, sudden movement – a jump, fall or knock – may cause an injury to the skeleton. It may be a dislocation or a fracture. In case of dislocation the bones at the joint are dislodged from their normal position. The ligaments may be torn apart or injured causing pain and swelling.
 
 
A fracture is a break in the bone. The break may be of a hair line crack or serious break in one or more points or broken away. (Fig. 8.20). Fracture also causes pain or swelling. In all these cases the patient should soon be taken to a doctor or a hospital.
  1. Never try to reset the bones.
  2. Place the injured part in a comfortable position.
  3. Care should be taken to avoid jerk or movement of the injured part.
Q.26. How a bone is formed? What kind of food should we take for proper growth and upkeep of bones?

Ans. Before our birth, the skeleton forms as soft and elastic pieces of cartilage. Some of these cartilages, not all, are changed to bones. With the deposition of a substance containing Calcium and Phosphorus, the bones become hard and strong. When a baby is born its skeleton is soft. At old age the bones become hard and brittle.
For proper growth and upkeep of bones we need to take food which are rich in Calcium, Phosphorus, Vitamins and Proteins. Milk, curd, fruits, vegetables and eggs contain the needed nutrient.

Q.27. What is a bone marrow? Give its main function.

Ans.
The long bones such as the thigh bone, upper arm bones have bone marrow inside them. (Fig. 8.21). The bone marrow produce red blood cells. They also from some kinds of white blood cells.

 
Q.28. Discuss the mechanism of bone movement. What is the role of muscles in the movement of bones?

Ans. Two muscles work for the movement of a bone. When one muscle contracts it becomes shorter, stiffer and thicker. It pulls the bone in that direction. The other muscle of the pair relaxes. A muscle can only pull. It can not push. Hence to move the bone in opposite direction the relaxed muscle contracts to pull the bone towards its original position, while the first relaxes.
 
Q.29. What is locomotion? How does it help the animals?

Ans. When animals move from one place to other resulting in a change in their position it is called locomotion. Locomotion helps the animals in (1) search of food and shelter and (2) to escape from their enemies.

Q.30. How the birds are adapted for flying?

Ans. Birds can fly because their bodies are well suited for flying. Main adaptations for flying in birds are given below :
(i)  Body is streamlined.
(ii) Bones have air spaces.
(iii) Fore limbs are modified as wings.
(iv) Shoulder bones are strong.
(v) Breast bones are modified to hold massive muscles of flight.
(vi) Wings and tail are reinforced with big feathers.
(vii) Air sacs are connected with the lungs to make the body light and buoyant.
 
Q.31. Describe the mechanism of swimming in fishes.

Ans. The bodies of fishes are usually spindle shaped and streamlined. This makes it easy to move in water. There are also air filled swim bladders to make the body buoyant.
The skeleton of the body axis is covered by strong muscles. They are arranged serially segment by segment. During swimming, the front part of the body curves in one side and the tail part remains in the opposite side. It forms a loop. 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 aided by the fins of the tail. The paired and unpaired fins mainly help to keep the balance of the body and to keep direction.
 
Q.32. Comment on the mode of locomotion in following animals :
           (a) Snake         (b) Cockroach            (c) Snail             (d) Earthworm
Ans.
  1. Snake : In long snakes there are large number of vertebrae. The body muscles are very slender and numerous. They interconnect the adjoining vertebrae, ribs and skin. They are also connected to far removed segments by tendons.
Locomotion in a snake is like swimming on land. They make many loops at the sides. It is mainly the forward thrust of the loops against the surface that makes the snake to move forward (Fig. 8.25). They also hitch the skin and body alternately dragging the ventral scales on the ground. Some snakes can swim well in water.
 
 
 
  1. Cockroach : The cockroach walks on limb as well as fly in the air. They have three pairs of jointed legs attached to the breast region. These help in walking. There are two pairs of wings attached to the breast. The forewings are narrow. The hind wings are broad and thin with supporting veins.
In the breast region there are strong large muscles which move the legs for walking and wings while flying.
 
 
  1. Snail : The body of a snail is covered with a hard shell. It has an opening with a lid. Through the opening of the shell, a strong muscular foot comes out (T he foot is a part of its belly) and performs a very slow wavy motion. The shell can not help in locomotion. It has to be dragged along.
 
 
  1. Earthworm : The body of a mature earthworm seems to be made of many rings joined end to end. From the paler under surface of the body a large number of minute bristles project out. The bristles are connected with muscles at their bases. The bristles help to get a good grip on the ground. There are muscles in the body wall which help to extend and shorten the body. During movement, the earthworm first extend the front part of body keeping the rear fixed to the ground. Then it fixes the front end and release the rear end (Fig. 8.28). Thereafter it shortens the body and pulls the rear and forward. The earthworm follow this process repeatedly to move ahead. On a slippery surface its movement is affected due to the loose grip on the surface.
 
 
 
 
 
 

OBJECTIVE TYPE QUESTIONS
Q.1. Match the following items given in Column A with that in Column B :
Column A

Column B

(a)Snails

(b) Earthworm
 
 
 (c) Insects
 
 (d) Fish
 
 (e) Snakes
 
 
 (f) Birds
 
 (g) Leech
 
 (h) Ligament
 
 (i) Tendon
 
 (j) Joint
 
 (k) Bone marrow

(i) Breast is connected with 3 pairs legs and 2 pairs of wings.
 
(ii) Crawl on the ground by alternately looping sideways.
 
(iii) Swim with the help of muscles.
 
(iv) Joins bones to muscles.
 
(v) Swim by forming loops alternately on two sides of body.
 
(vi) Joins bone to bones.
 
(vii) A place where two bones meet together.
 
(viii) Move by muscular foot.
 
(ix) Produces RBCs.
 
(x) Fly by flapping its wings.
 
(xi) Move by alternate extension and contraction of the body.
 
Q.2. Fill in the blanks with appropriate words :
  1. The body parts which are specialized to do important body activities are called
………... .
  1. The organs are made of many kinds of ………. .
  2. A group of similar ………. with same kind of function is called a tissue.
  3. An organ though composed of different kinds of tissues, works as a ………. .
  4. Organs which can be seen from ………… are called external organs.
  5. Organs inside our body are called ………… organs.
  6. Red blood cells and some white blood cells are produced in the ………. of the bone.
  7. Our skeleton is made up of many pieces of ……….. and ………. .
  8. We can get photographs of bones by a machine called ………….. machine.
  9. Lower jaw is ………… .
  10. The backbone forms a ……….. bony tube.
  11. …………. is the strongest and longest bone in the body.
  12. The place where two or more bones meet together is called a ………. .
  13. Bodies of fishes are usually spindle shaped and ………… .
  14. Place to place movement of animals is called ……… .
  15. ………… and swans also swim in water.
Q.3. State whether the statements given below are True or False :
  1. The bones are soft while cartilages are hard.
  2. Skeleton system gives the body support and protect inner organs.
  3. Doctors use X-ray films to examine the injuries of bones.
  4. The bones of cranium are flat and firmly like a zipper.
  5. Upper jaw is movable.
  6. Five vertebrae of hip and four vertebrae of tail are fused.
  7. Bones in the foot are normally set in an arch.
  8. A human body is born with about 206 bones.
  9. There are air sacs connected with the lungs in birds.
  10. Locomotion in a snake is like swimming on land.
  11. Muscular foot in snail is part of its belly.
  12. The bones are moved by simultaneous contractions and relaxation of two sets of muscles.
  13. All joints in our body are similar.
  14. Cockroaches can not walk.
  15. The minute movable bristles in earthworm help in gripping the ground.
 
 
 
Q.4. Choose the correct option in the following questions :
  1. Skeleton of human body is made up of
  2. bones                                              (b) cartilage
(c) both bones and cartilage                 (d) none of these
  1. Human skeleton comprises
  2. skull and backbone                            (b) ribs and breast bone
(c) shoulder and hipbones                      (d) all of these
  1. Fixed joints are found in
  2. lower jaw                                              (b) skull
(c) hands                                                    (d) hipbone
  1. Knee joints are
  2. hinge joints                                          (b) ball and socket joints
(c) pivotal joints                                         (d) fixed joints
  1. Fishes swim by
  2. forming loops alternately on two sides of the body
  3. forming loops on single side
  4. somersaulting
  5. alternate dipping and coming up
  6.  Which one of the following is the characteristics of birds?
  7. Strong muscles                                   (b) Light bones
(c) Hollow bones                                       (d) All of these
    (vii)    In cockroaches the body parts helping in movement are
  1. three pairs of legs and  two pairs of wings
  2. two pairs of legs and two pairs of wings
  3. two pairs of legs and three pairs of wings
  4. none of these
    (viii)   Muscular foot is a locomotary organ in
  1. snakes                                                  (b) earthworm
(c) housefly                                                (d) snails
     (ix)    The organ that protects the main nerve cord is
  1. skull                                                       (b) back bone
(c) breast bone                                          (d) chest bone
     (x)     The number of cervical vertebrae in man is
               (a) Ten                                                        (b) five
               (c) seven                                                     (d) eight
 

ANSWERS TO OBJECTIVE TYPE QUESTIONS
Q.1. Match the following items given in Column A with that in Column B :
Column A

Column B

(a) Snails

(b) Earthworm

 (c) Insects
 
 (d) Fish
 
 (e) Snakes
 
 (f) Birds
 
 (g) Leech
 
 (h) Ligament
 
 (i) Tendon
 
(j) Joint
 
 (k) Bone marrow

(viii) Move by muscular foot.
 
(xi) Move by alternate extension and contraction of the body.
 
(i) Breast is connected with 3 pairs legs and 2 pairs of wings.
 
(v) Swim by forming loops alternately on two sides of body.
 
(ii) Crawl on the ground by alternately looping sideways.
 
(x) Fly by flapping its wings.
 
(iii) Swims with the help of muscles.
 
(vi) Joins bone to bones.
 
 (iv) Joins bones to muscles.
 
(vii) A place where two bones meet together.
 
(ix) Produces RBCs.

Q.2. Fill in the blanks :
        (i) organs                    (ii) cells and tissues                       (iii) cells
        (iv) unit                       (v) outside                                      (vi) internal
        (vii) marrow                (viii) bones, cartilage                      (ix) X-ray
        (x) movable                (xi) hollow                                       (xii) Thigh bone
        (xiii) joint                     (xiv) streamlined                             (xv) locomotion
        (xvi) Ducks.
Q.3. True/ False :
        (i) False           (ii) True             (iii) True             (iv) True           (v) False
        (vi) True           (vii) True           (viii) False          (ix) True           (x) True
        (xi) True           (xii) False          (xiii) False          (xiv) False        (xv) True
Q.4. Choose the correct option :
  1. (c) Bones and cartilage form the skeleton of human body.
  2. (d) All are the part of human skeleton.
  3. (b) Joint in skull are immovable.
  4. (a) Knee joints are very similar to the hinges of a door.
  5. (a) During swimming, the front part of the body and the fail part curve in opposite direction. This makes a jerks and pushes the body forward. So fish forming loops alternatively on two sides of the body.
  6. (d) These are the adaption of birds for flying.
  7. (a) Three pairs of legs are the characteristics of insects.
  8. (a) With the help of muscles, ribs and scales, snake move from place to place.
  9. (a) Skull has 22 bones in cranium and 14 on the face. These are protect the brain and sensory organs.
  10. (c) Seven cervical vertebrae found in neck region.