STD-4, CHAPTER-1: MY BODY, EXTRA QUESTION ANSWERS

 1.      Name the sense organs of human body.

Ans: The sense organs of human body are, tongue, ears, skin, nose and eyes.

2.      What are external organs?

Ans: Those organs which can be seen from outside, are known as external organs.

3.      What are internal organs?

Ans: Those organs which are present inside our body and cannot be seen from outside, are called internal organs.

4.      How our body works?

Ans: Our body works with the help of various organs present in it.

5.      Name the components of food.

Ans: The different components of food are, carbohydrates, proteins, fats and other nutrients.

6.      Define ‘digestion’.

Ans: The process by which complex food materials are broken down into simpler forms, is called digestion.

7.      Define ‘digestive system’.

Ans: The system which is responsible for digestion, is called the digestive system.

8.      Name the organs that make up the digestive system.

Ans: The mouth, food pipe, stomach and intestines are the different organs that make up our digestive system.

9.      Name the first part of the digestive system.

Ans: Mouth is the first part of the digestive system.

10.  Name the organ through which food enters the stomach.

Ans: Food enters through our mouth.

11.    Name the organs present inside our mouth.

Ans: Teeth, tongue, are present inside our mouth.

12.  How do our teeth help us?

Ans: i) Teeth help to bite and chew the food.

ii) They also give shape to our face and help us to speak clearly.

13.  Name the two sets of teeth that are formed during one’s life time.

Ans: The two sets of teeth are, temporary teeth (milk teeth) and permanent teeth.

14.    When do the teeth begin to appear in a human baby?

Ans: When the baby is about six months old, his/her teeth begin to appear.

15.  The number of milk teeth (temporary teeth) in humans is ______

Ans: 20

16.  When do the temporary teeth (milk teeth) start to fall out?

Ans: Between the age of six and twelve years, the milk teeth fall out one by one.

17.  What are permanent teeth?

Ans: The set of teeth which replace the milk teeth, are the permanent teeth.

18.  What is the number of permanent teeth?

Ans: The number of permanent teeth in humans, is 32.

19.  Name the different types of teeth.

Ans: The different types of teeth are,

i)  Flat teeth (Incisors)

ii)Pointed teeth (Canines)

iii) Broad and Grooved teeth (Premolars and molars)

20.  Where the flat teeth are located?

Ans: Flat teeth, are located in the front of the mouth.

21.  What is the shape of incisors?

Ans: Incisors are flat in shape.

22.  What is the total number of incisors (flat teeth) in our mouth?

Ans:  Total 8 incisors are present in our mouth.

23.  How many incisors are present in each jaw?

Ans: 4 incisors are present in each jaw.

24.  What is the function flat teeth (incisors)?

Ans: The incisors are used for biting and cutting the food.

25.  Where the pointed teeth are located?

Ans: The pointed teeth are located on either side of flat teeth.

26.  What is the shape of canines?

Ans: Canines are pointed in shape.

27.  What is the number of canines in each jaw of human mouth?

Ans: 2 canines are present in each jaw of human mouth.

28.  What is the total number of canines in human mouth?

Ans: 4 canines are present in human mouth.

29.  What is the function of canines?

Ans: Canines are used for tearing the food.

30.  What is the shape of pre-molars and molars?

Ans: Pre-molars and molars are broad and grooved.

31.  Where are the pre-molars located?

Ans: Pre-molars are located next to canines.

32.  What is number of pre-molars in each jaw?

Ans: 4 pre-molars are present in each jaw.

33.  What is the total number of pre-molars in humans?

Ans: The total number of premolars in human mouth is 8.

34.  Where are molars located?

Ans: Molars are located next to premolars.

35.  What is the number of molars in each jaw?

Ans: The number of molars in each jaw of human being is 6.

36.  What is the total number of molars in human mouth?

Ans: The total number of molars in human mouth is 12.

37.  What is the function of molars and premolars?

Ans: molars and pre-molars are used for chewing and grinding the food.

38.  Name the different types of teeth present in the mouth. Also mention their numbers, location and functions.

Ans:

Type of teeth	Shape	Location	Number in Each Jaw	Total number in Human Mouth	Function
Incisors	Flat	In the front	4	8	Biting and cutting the food.
Canines	Pointed	On either side of incisors	2	4	Tearing the food
Premolars	Broad and Grooved	Next to canines	4	8	Chewing and grinding the food
Molars	Broad and Grooved	Next to premolars	6	12	Chewing and grinding the food.

 

39.  Why is it important to take care of our teeth?

Ans: If we do not take care of our teeth, they may decay and fall. So, it is important to take care of our teeth.

40.  Describe the ways to protect our teeth.

Ans:We should,

 i) Brush teeth twice a day- in the morning and at night.

ii) Wash our mouth after every meal.

iii) Avoid eating sweets or sugary snacks and taking soft drinks as much as possible.

iv) Visit a dentist for regular dental check ups.

v) Eat fruits, like apple and guava, and vegetables, like radish and carrot.

vi) Clean the tongue to remove germs.

vii) Eat calcium rich food, like eggs, milk and milk products for strong teeth.

41.  We should avoid eating sweets or sugary snacks and taking soft drinks, as they can cause ___.

Ans: Tooth decay

42.  Why should we eat fruits, like apple and guava?

Ans: We should eat fruits, like apple and guava as these foods give exercise to our gums.

43.  Why should we clean the tongue?

Ans: We should clean the tongue to remove germs.

44.  Eggs, milk and milk products are rich in _____.

Ans: Calcium

45.  A doctor for teeth is called a ______.

Ans: Dentist

46.  Describe the correct way to brush our teeth.

Ans: i) Brush up and down in front.

ii) Then brush up and down the back.

iii) Always brush the teeth with a circular movement.

47.  What is the cause of tooth decay?

Ans: If sugar and bacteria are left on the teeth for long, they can cause tooth decay.

48.  What is enamel?

Ans: The white outer covering of teeth is called enamel.

49.  Name the hardest substance in the human body. (OR) Name the white outer covering of teeth.

Ans: Enamel

50.  What is the function of tongue?

Ans: i) Tongue is used for tasting, licking and speaking.

ii) Tongue also pushes the food into the food pipe at the time of swallowing.

51.  Name the sensitive sites of tongue and their location.

Ans:i) The back of the tongue is sensitive to bitter taste.

  ii) Its sides are sensitive to sour and salty tastes.

iii) The tip of the tongue is sensitive to sweet taste.

52.  Name the glands present in the mouth.

Ans: Salivary glands are present in the mouth.

53.  How many pairs of salivary glands present in the mouth?

Ans: There are three pairs of salivary glands present in the mouth.

54.  Name the gland that secretes saliva.

Ans: The salivary glands secrete saliva.

55.  Name the part, where the process of digestion starts.

Ans: The process of digestion starts in the mouth.

56.  How the process of digestion is carried out in mouth?

Ans:i) Teeth helps in breaking the food into smaller pieces and chewing it.

ii) Saliva gets mixed with the food and makes it soft.

iii) Saliva converts insoluble starch into soluble sugar.

57.  Why is it important to chew the food properly?

Ans: It is important to chew the food properly for proper digestion of food.

58.  After chewing the chappati for a longer time, it starts tasting a little sweet. Why?

Ans: The saliva acts on the food. It converts the starch into sugar. So, after chewing the chappati for a longer time, it starts tasting a little sweet.

59.   The food from the mouth goes into the _____.

Ans: Food pipe

60.  The food from the food pipe goes into the _______.

Ans: stomach

61.  What happens to the food when it enters the stomach?

Ans: i) The stomach stores the food for a few hours.

ii) The food mixes with the digestive juices secreted by the walls of the stomach.

ii) The food is partially digested here.

62.  The food leaves the stomach and enters into the ______.

Ans: Small intestine

63.  Name the glands that pour their juices into the small intestine.

Ans: Liver and pancreas pour their juices into the small intestine.

64.  Name the largest gland of our body.

Ans: Liver is the largest gland of our body.

65.  What happens to the food when it enters the small intestine?

Ans: i) Juices from liver and pancreas, mixes with the food in the small intestine.

ii) The food gets completely digested.

iii) The walls of the small intestine absorb the digested food and pass it to blood.

66.  How the digested food reaches all parts of the body?

Ans: Blood carries the digested food from the small intestine to all parts of the body.

67.  What happens to the undigested food?

Ans: i) The undigested food passes into the large intestine.

ii) Then it is collected in the rectum and is eliminated through the anus.

68.  Which part of the digestive system absorbs water?

Ans: Large intestine absorbs water.

69.  What are the benefits of cooking food before eating?

Ans:i) Cooking makes the food soft, tasty and digestible.

ii) It also kills the germs that may be present in the food.

70.  Describe the points that should be kept in mind at the time of eating food.

(OR) List some good habits that should be taken care of at the time of eating food.

Ans: One should,

i) wash hands before eating.

ii) chew food properly before swallowing.

iii) not speak while chewing food.

iv) eat green vegetables and fruits everyday.

v) eat a balanced diet.

vi) take food at fixed intervals.

vii) drink about 8-10 glasses of water everyday.

71.  How can cooked as well as uncooked food become the source of many infections?

(OR) Why is it important to eat fresh and clean food?

(OR) Why is washing of fruits and vegetables important for us?

Ans: i) Unwashed fruits and vegetables can carry germs which may cause different diseases.

ii) Unwashed fruits and vegetables can also carry very small eggs of worms. When they reach our stomach, they can produce worms, making the person weak and unhealthy.

iii) Peeled and cut fruits and vegetables, which are exposed to flies and dust, can transfer germs into the body.

iv) Cooked food when left uncovered or unrefrigerated for long, can also cause food poisoning.

So, it is very important to eat fresh and clean food.

72.  Name some diseases that we are likely to suffer, by eating poisoned or unhealthy food.

Ans: We may suffer from, diarrhea, vomiting, jaundice, cholera, etc. by eating unhealthy food.

73.  How food poisoning occurs?

Ans:i) When food is kept uncovered or unrefrigerated for long, germs grow and multiply in the food.

ii) The germs produce harmful substances which results in food poisoning.

74.  What measures should be taken by a person suffering from diarrhea?

Ans: A person suffering from diarrhea and vomiting should take plenty of boiled water containing a small amount of sugar and salt.

STD-4, CHAPTER-5, BIRDS: BEAKS AND CLAWS, EXERCISE QUESTION ANSWERS

 A.     FILL IN THE BLANKS.

1.      Birds do not have ______ to eat.

Ans: teeth

2.      Sunbird ______ nectar from flowers.

Ans: sucks

3.      A duck has a _______ and broad beak.

Ans: flat

4.      A penguin uses its webbed feet to _____.

Ans: swim

5.      ______ and jacana are wading birds.

Ans: Crane

B.      MATCH THE FOLLOWING:

1.      sunbird                             (a) sifting beak

2.      eagle                                 (b) sticky beak

3.      Parrot                               (c) chiselling beak                                   

4.      duck                                  (d) probing beak

5.      swallow                            (e) curved beak

6.      woodpecker                    (f) crushing beak

7.      pigeon                               (g) piercing and tearing beak

      Ans:

1.      sunbird                             (d) probing beak

2.      eagle                                 (g) piercing and tearing beak

3.      Parrot                               (e) curved beak                                

4.      duck                                  (a) sifting beak

5.      swallow                            (b) sticky beak

6.      woodpecker                     (c) chiselling beak

7.      pigeon                               (f) crushing beak

C.      TICK THE CORRECT OPTION.

1.      A sparrow uses its short and hard beak for –

(a)   Sucking nectar from flowers                                      

(b)   Sifting food from mud

(c)    Catching flies while flying                 

(d)   Crushing of grains

Ans: crushing of grains

2.      A hoopoe takes out insects and worms from the holes in the ground with the help of its –

(a)   Strong, short and straight beak                                      

(b)   Long and slender beak

(c)    Broad beak that has holes on the sides                

(d)   Curved and hard beak

      Ans: long and slender beak

3.      A bird, that does not have strong and sharp claws is the –

(a)   eagle                                      

(b)   duck

(c)    vulture                 

(d)   hawk

      Ans: duck

4.      Birds, that have two toes pointing upwards and two downwards, are known as –

(a)   Scratching birds                                      

(b)   Wading birds

(c)    Climbing birds

(d)   Perching birds

      Ans: climbing birds

5.      It is a perching bird.

(a)   Sparrow                                      

(b)   jacana

(c)    hen    

(d)   duck

      Ans: sparrow

D.     ANSWER THE FOLLOWING QUESTIONS IN BRIEF.

1.      What do birds use for preening their feathers?

Ans: Birds use their beaks for preening their feathers.

2.      How is a crushing beak helpful to a pigeon?

Ans: The crushing beak helps in crushing seeds and grains, thereby, make it soft before eating.

3.      What are claws?

Ans: Claws are the long curved nails present on the feet.

4.      Name three birds of prey.

Ans: Eagle, vulture, and hawk are three birds of prey.

5.      What prevents the body of crane and jacana from sinking in water?

Ans: The widely spread out toes prevent the body of crane and jacana from sinking in water.

E.      ANSWER THE FOLLOWING QUESTIONS.

1.      Write two main uses of a beak of a bird.

Ans: i) Birds use their beaks to tear, bite, chisel or crush the food.

ii) Some birds use their beaks to fight the enemy or catch the prey.

2.      How are claws helpful to a bird?

Ans: Claws can be used for climbing, protecting, holding food, swimming and perching.

3.      How does a swallow catch its food?

Ans: i) The beak of a swallow is sticky from inside.

ii) This helps the swallow to catch flies while flying.

4.      How do webbed feet help a duck to swim?

Ans: The webbed feet of duck is used to paddle and to push the water while swimming.

5.      What type of feet do the scratching birds have?

Ans: i) Scratching birds have strong feet with three toes in front and one at the back.

ii) Each toe has a sharp claw to scratch the ground in search of seeds and insects present in the soil.