Breathing and Exchange of Gases
Class 11, Chapter 17
NEET MCQs Part - 2

1. Trachea is lined with incomplete rings of
a) Fibrous cartilage
b) Calcified cartilage
c) Elastic cartilage
d) Hyaline cartilage
Ans:- d) Hyaline cartilage
The trachea is surrounded by 16-20 rings of hyaline cartilage; these 'rings' are incomplete and C-shaped. Two or more of the cartilages often unite, partially or completely, and they are sometimes bifurcated at their extremities.

2. In man and mammals air passes from outside into lungs rmthrough

A. Nasal cavity,larynx pharynx trachea bronchi alveloi
B. Nasal cavity larynx pahrynx trechea branchioles branchi alveoli
C . Nasal cavity larynx pharynx trachea bronchiolrs alveoli
D . Nasal cavity pharynx larynx trachea bronchi branchioles alveoli
Answer : D

3. In which chronic disorder alveolar walls are damaged
a)asthma
b) emphysema
c)gout
d)cardiac arrest
Ans:b)emphysema

4. What is vital capacity of our lungs?
A. Inspiratory reserve volume plus tidal volume
B. Total lung capacity minus expiratory reserve volume
C. Inspiratory reserve volume plus expiratory reserve volume
D. Total lung capacity minus residual volume
Ans : D
Explanation
Vital capacity of lungs is the largest possible expiration after largest possible inspiration that is greatest. Volume of air can be exchanged in single respiration or amount of air breathed in and out with greatest possible efforts.
Vital capacity = TV + IRV + ERV
Total lung capacity = VC + RV
So we can say that VC = Total lung capacity - Residual volume

5. During forced expiration the actively contracting muscles include....
A) Diaphragm
B)External intercostals
C) abdominal muscles
D) all of these
Answer...(C) abdominal muscles

6. 1molecule of myoglobin can bind with how many molecules of O2 ?
A)1
B)2
C)3
D)4
Answr: a)1

7. Cardiac notch is present in which lung(s)?
a) right lung
b) left lung
c) both lungs
d) none of these
Answer ; b

8. When you hold your breath,which of the following gas changes in blood would first lead to the urge to breathe?
A.rising CO2 concentration.
B.falling CO2 concentration.
C.rising CO2 and falling O2 concentration.
D.falling O2 concentration.
Answer:A
solution:
Chemoreceptors in the medulla get stimulated by increase in CO2 concentration in the blood of arteries. Decrease in O2 concentration has no significant effect on chemoreceptors.

9. A Zoologist compared the respiratory efficiency and swimming speed of different fish. He found that less efficient fish tended to have
a) greater ventilation
b) a thicker respiratory surface
c) more haemoglobin
d) a faster heart rate helium in trachea of mammals
Ans : b) a thicker respiratory surface

10. Which structure of mam is similar to spiracle of cockroach?
A.bronchioles
B.nostrils
C.lungs
D.alveoli
Ans : B

11. The exchange of gases in the alveoli of the lungs takes place by
a)passive transport
b)active transport
c)osmosis
d)simple diffusion
Ans:d
The exchange of gases in the alveoli
Of the lungs takes place by simple diffusion the exchange of gases between the alveoli and blood in the lungs is the result of difference in partial pressure of respiratory gases

12. Where does the respiratory passage separate from the oesophagus?
A) internal nares
B) trachea
C) nasal chamber
D) glottis
Ans: D

13. Rheumatic fever can cause damage
(a) Alveoli of the Lungs
(b) heart valves
(c) heart muscles
(d) pleural membranes function
Ans:b. heart valves

14. The globin portion of Fetal haemoglobin-F is made of....
A)one-α and one-β
B)Two-α and one-β chains
C)Two-α and Two-β chains
D)Two-α and Two-γ chains
Ans: d)Two-α and Two-γ chains.

15. Other name of Decompression sickness is.....
A)Bend's disease
B)caisson's disease
C)Dysbarism
D)all the above
Answer: d)all the above.

16. Normal quiet breathing is ....
A) apnea
B)Eupnea
C)Dyspnea
D)Asphysia
Answer....(B) Eupnea

17. The function of pneumotaxic centre is
(a) regulate inspiration
(b) regulate rhythm
(c) increase heart rate
(d) all of the above
Answer
Answer: (a) regulate inspiration
Explanation:
Pneumotaxic centre lies in pons in the brain. It regulates inspiration.

18. The movement of chloride ions into erythrocytes from the placenta to maintain osmotic balance during the transport of gases is known as???
a.Bohr effect
b.Hamburger phenomenon
c.Haldane effect
d.Drinker's respiration
Ans. Option b
Explanation:
Loss of bicarbonate ions from RBC causes positive charge inside RBC which is balanced by diffusion of chloride (Cl-) ion from plasma into the RBC. This phenomenon of chloride shift maintain the electrical neutrality of cell. This phenomenon is also known as Hamburger phenomenon.

19. Name the chronic respiratory disorder caused mainly by cigarette smoking?
A. Asthma
B. Respiratory acidosis
C. Respiratory alkalosis
D. Emphysema
Explanation:
Emphysema is a chronic obstructive pulmonary disease (COPD) caused due to cigarette smoking. It is an inflation or abnormal distention of the bronchioles or alveolar sacs of the lungs which causes irreversible distension and loss of elasticity of alveoli of the lungs.

20. pressure gradient between atmosphere and pulmonary cavity is created by.......
1) external intercostal muscle
2) diaphragm
3) both 1 and 2
4) contraction of lungs
ANS: 3) BOTH 1 AND 2

21. What is the medicine used to treat emphysema?
a. Alphadextrin
b. Alpha 1 anti trypsin
c. Alpha lactalbumin
d. Retrodivir
Ans: b. Alpha 1 anti trypsin

22. A Spirometer can be used to measure directly
a)Inspirtory capacity
b)residual volume
c)total lung capacity
d)none of these
answer : option a

23. Select the correct statement
A. Expiration occurs due to external intercostal muscles
B. Intrapulmonary pressure is lower than the atmospheric pressure during inspiration
C. Inspiration occurs when atmospheric pressure is less than intrapulmonary pressure.
D. Expiration is initiated due to contraction of diaphragm
Ans: B
EXPLANATION
Intrapulmonary pressure is lower than the atmospheric pressure during inspiration

24. The percentage of CO2, Oxygen and nitrogen in exhaled air of man are about:
A) 0.04 : 16 : 79
B) 0.4 : 29 : 70
C) 4.0: 20 : 79
D) 4.0 : 16 : 79
Correct answer: OPTION D

25. The red coloured ,Fe containing pigment present in human body is
A)haemoglobin
B)myoglobin
C)globin
D)both A and B
Ans:"D)both A and B"

26. Name the chronic respiratory disorder caused mainly by cigarette smoking?
a)respiratory acidosis
b)respiratory alkalosis
c) emphysema
d)asthma
Ans:c

27. G.S Carter classified respiration into ___ types
A)4
B)1
C)3
D)2
Ans c)
External ,internal ,cellular

28. WHEN YOU HOLD YOUR BREATH, WHICH OF THE FOLLOWING HAS CHANGES IN BLOOD WHICH WOULD FIRST LEAD TO THE URGE TO BREATH?
A) RISING O2 CONCENTRATION
B) RISING CO2 CONCENTRATION
C) RISING O2 AND RISING CO2 CONCENTRATION
D) LOWERING CO2 CONCENTRATION
ANS : RISING CO2 CONCENTRATION

29. Which of the following does not shift the oxy-haemoglobin dissociation curve to the right' ??
a) increased pH
b) increased carbon dioxide
c) increased temperature
d) 2,3-DPG
Answer : a.)

30. A center that moderates the function of the respiratory rhythm center is located in A.Dorsal medulla oblongata
B.ventral medulla oblongata
C.Pons
D.pre central gyrus of cerebrum
Ans...option c Pons
Exp...centre present in the pons region of the brain called pneumotaxic centre can moderate the functions of the respiratory rhythm centre

31. _____ is called as "Sound box"
a. Trachea
b. Larynx
c. Lungs
d. Bronchi
Answer:- Larynx

32. The majority of CO2 produced by our body cells is transported to the lungs
a. as bicarbonates
b. as carboxyhemoglobin
c. dissolved in plasma
d. dissolved in blood
Ans. a. bicarbonates( about 70%)
Dissolved in plasma - 7%
As carboxyhemoglobin - 20 to 25%

33. Concentration of H2CO3 does not increase in blood due to the presence of
A) Na+
B) Ca++
C) Mg++
D) K++
Ans:A
In the acid base homeostasis the bicarbonate buffering system of blood is an important buffering system .in plasma the alkaline phospate combines with carbonic acid and forms sodium bicarbonate.

34. A person suffers punctures in his chest cavity in an accident without any change to the lungs its effect could be
a) reduced breathing rate
b) rapid increase in breathing rate
c) no change in respiration
d) cessation of breathing
Ans: cessation of breathing is the answer.
The reason is the exchange of gases through lungs is due to the development of pressure gradient which is between the lungs and atmosphere. Punctures in the chest may lead to loss of this pressure gradient so resulting in cessation of breathing.

35. Carbon monoxide can kill a person because of it's extremely high affinity for .
A heamoglobin.
C cytochrome
B no-no of these
D phytochrome
Ans is A. haemoglobin

36. Hypoxia means
A. Shortage of oxygen in the tissue
B. Excess of oxygen in the tissue
C. Excess of carbon dioxide in the tissue
D. Shortage of carbon dioxide in the tissue
Ans: shortage of oxygen in the tissue

37. The respiratory centre in brain which controls inspiration and expiration in situated in
Or
Respiration and vomiting centre are located in
A) Medulla oblogata
B) Cerebellum
C) Hypothalamus
D) pericardium
Ans : A

38. Carbonic anhydrase is present in
1) plasma of blood
2) RBC
3) WBC
4) Both 1 and 2
Ans: 2) RBC
Explanation: it is the enzyme present in RBC which helps to convert CO2 into carbonic acid and bicarbonate ion.

39. Nature and shape of tracheal rings?
A) elastic, complete and C shaped
B) fibrous, incomplete And U shaped
C) hyaline, incomplete and C shaped
D) hyaline, complete and C shaped
Answer:) option) D

40. Which region of respiratory system is called sound box?
a) pharynx.
b)larynx
c)trachea.
d) alveoli
Ans:b)larynx
Explaination:larynx is a cartilaginous box which help in sound production and hence called sound box.

41. Instrument used to measure the inhaled and exhaled amount of air................
A)Anemometer
B)Barometer
C)Spirometer
D)All the above
Answr: c)spirometer, also known as pulmometer.

42. Thoracic cage of man is formed of
1.ribs and sternum
2.ribs, sternum and thoracic vertebrae
3.ribs, sternum and lumbar vertebrae
4.ribs and thoracic vertebrae
Answer: 2

43. A person is suffering from frequent episodes of Nasal discharge, Nasal congestion,Reddening of eyes and watery eyes.These are the symptoms of.....
A)Cyanosis
B)Bronchitis
C)Rhinitis
D)Bronchial carcinoma
Ans: b)Bronchitis

44. The change in Blood O2 capacity as a result of PH change is called........
A)Bohr effect
B)pasteur effect
C)Root effect
D)Lansteiner effect
Ans: c)Root effect

45. Maximum number of oxygens haemoglobin can carry is ?
A)2
B)3
C)4
D)0
The correct answer is C) 4

46. In human beings Lungs are divided into
A) 2 right and 2 left lobes
B) 3right and 2 left lobes
C) 2right and 3left lobes
D) 3right and 3 left lobes
Ans:B

47. Skin is an accessory organ of respiration in .........
a. Frog
b. Rabbit
c. Humans
d. Lizards
Answer: Frog

48. When under certain condition,the P50 value of haemoglobin increase, the affinity of pigment of OXYGEN will
1.Remain same
2.Rise
3.Fall
4.First rise and then fall
Ans: 3.Fall

49. what amount of carbon dioxide is delivered by every 100 ml of deoxygenated blood to the alveoli ?A.4 mlB.3mlC.5 mlD.8ml Ans...option A 4 mlExplanation -Every 100 ml of deoxygenated blood delivers approximately 4 ml of CO2 to the alveoli.
50. A healthy human breaths ______ times per min(a)16-20
(b)13-17
(c)12-16
(d)10-20
Correct option:(c)

51. Number of alveoli in the human lungs has been estimated to be approximately
A) 100 million
B) 300 million
C)125 million
D) 300 billion
Ans: B) 300 million

52. Respiratory quotient is measured by..........
A)Ganong's Pulmometer
B)Gonong's Respirometer
C)Glensen's Spiromter
D)Glensen's Respirometer
Ans: b)Gonong's Respirometer.

53. Sound box in birds is known as
1.layrnx
2.syrinx
3.pygostyle
4.synsacrum
Answer: syrinx

54. The solubility of CO2 is _____
times higher than that of O2
(a)15-20 times
(b)20-25 times
(c)25-30 times
(d)30-35 times
Correct option: (b)

55. SELECT THE CORRECT STATEMENT
A) THE OXYGEN DISSOCIATION CURVE IS DIFFERENT FOR FOETAL HAEMOGLOBIN AND NORMAL HAEMOGLOBIN
B) THE OXYGEN CARRYING CAPACITY OF FOETAL HAEMOGLOBIN AND NORMAL HAEMOGLOBIN IS SAME
C) FOETAL HAEMOGLOBIN HAS GREATER AFFINITY TO OWYGEN THAN NORMAL HAEMOGLOBIN
D) BOTH A AND C
ANSWER: OPTION D

56. The exchange of gases in the alveoli of lungs takes place by
1.Passive transport
2.Active transport
3.Osmosis
4.Simple diffusion
A: Simple diffusion

57. which of the following pulmonary volume CANNOT be measured by Spirometer
(a) FRC
(b) TCL
(c) VC
(d) both (a) & (b)
Correct option: (d)
Actually speaking Spirometer cannot measure RV
FRC=ERV+RV,
TLC=RV+ERV+TV+IRV
and hence the capacities which includes RV cannot be measured by spirometer

58. The hemoglobin of a human foetus
A. its affinity for oxygen is the same as that of an adult
B. has a lower affinity for oxygen than that of an adult
C. has a higher affinity for oxygen than that of an adult
D. has only 2 protein subunits instead of 4
Answer:C

59. bBue baby syndrome results from
1)excess of total dissolved solids
2)excess of chlorine
3)formation of methaemoglobin
4)excess of dissolved oxygen
Ans : (3)

60. The pneumataxic centre is present in _________
a. Merula
b. Cerebrum
c. Pons verolli
d.cerebellum
Ans : c

61. When you hold your breath, which of the following gas changes in blood 1st lead to urge to breath?
A. Rising of co2 conc
B.falling co2 conc
C.rising co2 and falling on conc
D.falling o2 conc
Ans= (A)

62. visiting high mountains may cause altitude sickness in men living in plain areas. the prime cause of this is
a) excess CO2 in the blood
b) decreased efficiency of hemoglobin
c)decreased partial pressure of oxygen
d)decreased efficiency of red blood cells
Answer: c

63. Ratio of oxyhaemoglobin and haemoglobin in blood is based upon
a) oxygen tension
b) carbon-di-oxide tension
c) carbonate tension
d) Bicarbonate tension
Ans: Oxygen tension

64. The impulse for voluntary muscles for forced breathing starts in
a) medulla
b) cerebrum
c)cerebellum
d) vagus nerve
Ans:"b"

65. How many molecules of oxygen does one haemoglobin carries
A.4
B.2
C.6
D 8
Answer is option (a) 4
Explanation: Haemoglobin contains a protein called globin and a pigment called haem.The haem portion consists of 4 atoms of iron,each capable of combining with a molecule of Oxygen. Sohaemoglobin carries 4 molecules of oxygen

66. Adam’s apple represents
(A) Cricoid cartilage
(B) Thyroid cartilage
(C) Arytenoid cartilage
(D) Epiglottis
ANS: b) thyroid cartilage
Explanation:Thyroid cartilage from a subcutaneous projection, prominent in male.

67. In breathing movements air volume can be estimated by
1.stethoscope(our friend)
2.Hygrometer
3.Sphygmomanometer
4.spirometer
Ans:spirometer
Sphygmomanometer is used for measuring blood pressure

68. Heart of heart is
1. SA node
2.AV node
3.bundle of his
4. Purkinje fibresAnswer: SA node

69. Chemosensitive area of respiratory center in medulla is affected by
1.less co2 and h+
2.less O2 and h+
3.excess co2 and h+
4. Excess O2 and h+
Answer: excess co2 and h+

70. Molluscs contain copper containing blood pigment called ______
Options
A. Hemoglobin
B. Heamoerythryin
C. Heamocyanin
D. Echinochorme
Ans :c heamocyanin

71. Blood does not transport oxygen in
a) earthworm
b) cockroach
c) frog's tadpole
d)mammalian foetus
ANS:"B" (DUE TO ABSENSE OF RESPIRATORY PIGMENT)

72. A child was killed through Asphyxiation. Post morturm confirmed it because a piece of lung is put in water

1.settled down
2.kept floating
3.had blood spots
4.none of the above

Answer:kept floating

73. Emphysema is a ________
a). cardiovascular deisease
b).pulmonary diseace
c).neural disease
d).renal disease
Ans:- option b.pulmonary disease

Sphygmomanometer is used for measuring blood pressure

Answer: SA node