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NEET ]1[ Contd...

NEET Biology - Breathing and Exchange of Gases

Duration: 80 minutesTotal Marks: 320Questions: 80Negative Marking: -1

Instructions:

Each question has four options (1), (2), (3), (4). Choose the most correct answer.
Each correct answer carries 4 marks.
Each wrong answer will deduct 1 marks.
Unanswered questions will not be penalised.

1.In the uploaded NCERT/PDF text, the process called breathing, commonly known as respiration, refers most precisely to:

(1)Oxidation of glucose inside mitochondria only

(2)Exchange of O2 from atmosphere with CO2 produced by cells

(3)Movement of air only through the nasal chamber

(4)Transport of O2 only by haemoglobin

2.Which of the following pairings is incorrectly matched?

(1)Sponges/coelenterates/flatworms - diffusion over body surface

(2)Earthworm - moist cuticle

(3)Insects - gills

(4)Fishes - gills

3.Consider the statements:
A. Fishes respire through gills.
B. Amphibians, reptiles, birds and mammals respire through lungs.
C. Frogs can respire through moist skin also.
Choose the correct option.

(1)A and B only

(2)B and C only

(3)A and C only

(4)A, B and C

4.Correct sequence of air passage in humans is:

(1)External nostrils → nasal chamber → pharynx → larynx → trachea → primary bronchi

(2)External nostrils → pharynx → nasal chamber → larynx → trachea → primary bronchi

(3)Nasal chamber → external nostrils → larynx → pharynx → trachea → primary bronchi

(4)External nostrils → nasal chamber → larynx → pharynx → trachea → primary bronchi

5.Which part of the human respiratory passage is described as a common passage for food and air?

(1)Nasal chamber

(2)Larynx

(3)Pharynx

(4)Trachea

6.The sound box in humans is:

(1)Pharynx

(2)Larynx

(3)Trachea

(4)Epiglottis

7.Which statement is correct?

(1)Epiglottis prevents food entering the larynx by covering the glottis during swallowing.

(2)Glottis is a thin elastic cartilaginous flap that covers the epiglottis.

(3)Epiglottis prevents air entering the nasal chamber during inspiration.

(4)Glottis covers the trachea during normal breathing.

8.Trachea divides into right and left primary bronchi at the level of:

(1)3rd cervical vertebra

(2)5th thoracic vertebra

(3)7th thoracic vertebra

(4)10th thoracic vertebra

9.After primary bronchi, the correct branching sequence is:

(1)Secondary bronchi → tertiary bronchi → bronchioles → terminal bronchioles → alveoli

(2)Tertiary bronchi → secondary bronchi → bronchioles → terminal bronchioles → alveoli

(3)Secondary bronchi → bronchioles → tertiary bronchi → alveoli → terminal bronchioles

(4)Bronchioles → secondary bronchi → tertiary bronchi → terminal bronchioles → alveoli

10.Incomplete cartilaginous rings support all of the following EXCEPT:

(1)Tracheae

(2)Primary bronchi

(3)Tertiary bronchi

(4)Alveoli

11.Alveoli are best described as:

(1)Thick-walled non-vascular air tubes

(2)Thin, irregular-walled, vascularised bag-like structures

(3)Cartilaginous rings in the trachea

(4)Elastic flaps covering the glottis

12.Which statement about pleura is correct?

(1)Lungs are covered by single-layered pleura without fluid.

(2)Pleural fluid increases friction on lung surface.

(3)Outer pleura contacts thoracic lining and inner pleura contacts lung surface.

(4)Inner pleura contacts thoracic lining and outer pleura contacts lung surface.

13.Match the column:
(a) Conducting part (i) Alveoli and ducts
(b) Exchange part (ii) External nostrils up to terminal bronchioles
(c) Conducting function (iii) Actual diffusion of O2 and CO2
(d) Exchange function (iv) Transports, clears, humidifies and warms air

(1)a-ii, b-i, c-iv, d-iii

(2)a-i, b-ii, c-iii, d-iv

(3)a-ii, b-i, c-iii, d-iv

(4)a-iv, b-iii, c-ii, d-i

14.Assertion A: Any change in thoracic cavity volume is reflected in pulmonary cavity volume.
Reason R: We can directly alter pulmonary volume by active contraction of alveoli.

Choose the correct answer.

(1)Both A and R are true and R is the correct explanation of A.

(2)Both A and R are true but R is not the correct explanation of A.

(3)A is true but R is false.

(4)A is false but R is true.

15.Match thoracic chamber boundary with structure:
(a) Dorsal (i) Sternum
(b) Ventral (ii) Ribs
(c) Lateral (iii) Vertebral column
(d) Lower side (iv) Diaphragm

(1)a-iii, b-i, c-ii, d-iv

(2)a-i, b-iii, c-ii, d-iv

(3)a-iii, b-ii, c-i, d-iv

(4)a-iv, b-i, c-ii, d-iii

16.Which is the correct sequence of respiration steps as listed in the PDF?

(1)Pulmonary ventilation → alveolar diffusion → blood transport → tissue diffusion → cellular use of O2

(2)Blood transport → pulmonary ventilation → tissue diffusion → alveolar diffusion → cellular use of O2

(3)Alveolar diffusion → pulmonary ventilation → tissue diffusion → blood transport → cellular use of O2

(4)Pulmonary ventilation → cellular use of O2 → alveolar diffusion → blood transport → tissue diffusion

17.Inspiration occurs when:

(1)Intrapulmonary pressure is higher than atmospheric pressure

(2)Intrapulmonary pressure equals atmospheric pressure and no gradient exists

(3)Intrapulmonary pressure is less than atmospheric pressure

(4)Atmospheric pressure becomes negative with respect to lungs

18.Expiration takes place when:

(1)Intrapulmonary pressure is lower than atmospheric pressure

(2)Intrapulmonary pressure is higher than atmospheric pressure

(3)Thoracic volume is at maximum and pulmonary pressure is low

(4)External nostrils close temporarily

19.Choose the correct statements:
A. Diaphragm contraction increases thoracic volume in antero-posterior axis.
B. External intercostal contraction lifts ribs and sternum.
C. Lifting ribs and sternum increases thoracic volume in dorso-ventral axis.
D. Increased pulmonary volume increases intrapulmonary pressure.

(1)A, B and C only

(2)B, C and D only

(3)A and D only

(4)A, B, C and D

20.Correct sequence during normal inspiration is:

(1)Thoracic volume ↑ → pulmonary volume ↑ → intrapulmonary pressure ↓ → air enters lungs

(2)Pulmonary volume ↓ → intrapulmonary pressure ↓ → air enters lungs → thoracic volume ↑

(3)Thoracic volume ↑ → intrapulmonary pressure ↑ → air enters lungs

(4)Diaphragm relaxes → thoracic volume ↑ → pulmonary volume ↑ → air enters lungs

21.Correct sequence during normal expiration is:

(1)Relaxation of diaphragm/intercostals → thoracic volume ↓ → pulmonary volume ↓ → intrapulmonary pressure ↑ → air expelled

(2)Contraction of diaphragm/intercostals → thoracic volume ↓ → pulmonary pressure ↓ → air expelled

(3)Relaxation of diaphragm/intercostals → pulmonary volume ↑ → intrapulmonary pressure ↓ → air expelled

(4)Additional abdominal muscles relax → thoracic volume ↑ → expiration

22.Average breathing rate of a healthy human according to the PDF is:

(1)6-8 times/min

(2)8-10 times/min

(3)12-16 times/min

(4)20-25 times/min

23.The instrument used to estimate the volume of air involved in breathing movements is:

(1)Sphygmomanometer

(2)Spirometer

(3)Stethoscope

(4)Haemocytometer

24.A student breathes 14 times/min with a tidal volume of 500 mL. Approximate volume of air inspired per minute is:

(1)500 mL

(2)1400 mL

(3)7000 mL

(4)14000 mL

25.Using tidal volume 500 mL and breathing rate 12/min, approximate air inspired in one hour is:

(1)36 L

(2)360 L

(3)600 L

(4)720 L

26.Tidal volume is:

(1)Air remaining after forcible expiration

(2)Air inspired or expired during normal respiration

(3)Additional air inspired by forcible inspiration

(4)Maximum air in lungs at end of forced inspiration

27.Match volume with approximate value:
(a) TV (i) 1100-1200 mL
(b) IRV (ii) 1000-1100 mL
(c) ERV (iii) 500 mL
(d) RV (iv) 2500-3000 mL

(1)a-iii, b-iv, c-ii, d-i

(2)a-iii, b-ii, c-iv, d-i

(3)a-i, b-iv, c-ii, d-iii

(4)a-iv, b-iii, c-ii, d-i

28.Air remaining in the lungs even after forcible expiration is:

(1)ERV

(2)IRV

(3)RV

(4)TV

29.Which formula pair is correct?

(1)IC = TV + IRV; EC = TV + ERV

(2)IC = TV + ERV; EC = TV + IRV

(3)IC = ERV + RV; EC = IRV + RV

(4)IC = VC + RV; EC = TV + RV

30.The volume of air remaining in lungs after a normal expiration is:

(1)VC = TV + IRV + ERV

(2)FRC = ERV + RV

(3)TLC = VC + RV

(4)EC = TV + ERV

31.Vital capacity is represented by:

(1)TV + IRV

(2)TV + ERV

(3)ERV + TV + IRV

(4)RV + ERV

32.Total lung capacity equals:

(1)VC + RV

(2)TV + IRV only

(3)ERV + RV only

(4)TV + ERV only

33.If TV = 500 mL, IRV = 3000 mL, ERV = 1000 mL and RV = 1200 mL, then TLC is:

(1)3500 mL

(2)4500 mL

(3)5700 mL

(4)6200 mL

34.If ERV = 1100 mL and RV = 1200 mL, functional residual capacity is:

(1)1200 mL

(2)2300 mL

(3)1700 mL

(4)3400 mL

35.Choose the correct statements about exchange of gases:
A. Alveoli are primary sites of gas exchange.
B. Exchange also occurs between blood and tissues.
C. Gas exchange occurs mainly by active transport.
D. Thickness of diffusion membrane affects diffusion rate.

(1)A, B and D only

(2)A and C only

(3)B, C and D only

(4)A, B, C and D

36.Pressure contributed by an individual gas in a mixture of gases is called:

(1)Osmotic pressure

(2)Partial pressure

(3)Vapour pressure

(4)Intrapulmonary pressure

37.Compared with alveolar air, atmospheric air has:

(1)Lower pO2 and higher pCO2

(2)Higher pO2 and lower pCO2

(3)Higher pO2 and higher pCO2

(4)Lower pO2 and lower pCO2

38.Correct pO2 value for deoxygenated blood involved in diffusion is:

(1)159 mm Hg

(2)104 mm Hg

(3)95 mm Hg

(4)40 mm Hg

39.Correct pCO2 value for tissues is:

(1)0.3 mm Hg

(2)40 mm Hg

(3)45 mm Hg

(4)104 mm Hg

40.Correct direction of gas diffusion is:

(1)O2: tissues → blood → alveoli; CO2: alveoli → blood → tissues

(2)O2: alveoli → blood → tissues; CO2: tissues → blood → alveoli

(3)O2 and CO2 both move from alveoli to tissues only

(4)O2 and CO2 both move from tissues to alveoli only

41.Compared to O2, the solubility of CO2 is approximately:

(1)2-3 times higher

(2)5-10 times higher

(3)20-25 times higher

(4)100 times lower

42.Match diffusion membrane layer/feature:
(a) Layer 1 (i) Basement substance between them
(b) Layer 2 (ii) Thin squamous epithelium of alveoli
(c) Layer 3 (iii) Endothelium of alveolar capillaries
(d) Thickness (iv) Much less than a millimetre

(1)a-ii, b-iii, c-i, d-iv

(2)a-iii, b-ii, c-i, d-iv

(3)a-i, b-iii, c-ii, d-iv

(4)a-ii, b-i, c-iii, d-iv

43.Medium of transport for O2 and CO2 in humans is:

(1)Lymph only

(2)Pleural fluid

(3)Blood

(4)Alveolar air only

44.Approximate percentage of oxygen transported by RBCs is:

(1)3%

(2)7%

(3)70%

(4)97%

45.Oxygen carried dissolved in plasma is approximately:

(1)3%

(2)7%

(3)20-25%

(4)70%

46.Major form of CO2 transport in blood is:

(1)Dissolved plasma CO2, about 70%

(2)Bicarbonate, about 70%

(3)Carbamino-haemoglobin, about 70%

(4)Oxyhaemoglobin, about 70%

47.Match gas transport mode with percentage:
(a) O2 by RBCs (i) 7%
(b) O2 dissolved in plasma (ii) 70%
(c) CO2 as bicarbonate (iii) 97%
(d) CO2 dissolved in plasma (iv) 3%

(1)a-iii, b-iv, c-ii, d-i

(2)a-iv, b-iii, c-ii, d-i

(3)a-iii, b-i, c-ii, d-iv

(4)a-ii, b-iv, c-iii, d-i

48.Each haemoglobin molecule can maximally carry:

(1)One O2 molecule

(2)Two O2 molecules

(3)Four O2 molecules

(4)Eight O2 molecules

49.Choose the correct statements:
A. Haemoglobin is red coloured and iron containing.
B. O2 binds irreversibly with haemoglobin to form oxyhaemoglobin.
C. O2-Hb binding is mainly related to pO2.
D. pCO2, H+ and temperature can interfere with O2-Hb binding.

(1)A, C and D only

(2)A and B only

(3)B, C and D only

(4)A, B, C and D

50.Oxygen dissociation curve is obtained by plotting:

(1)pCO2 against pO2

(2)Percentage saturation of haemoglobin with O2 against pO2

(3)Tidal volume against time

(4)pH against temperature

51.Which set favours formation of oxyhaemoglobin in alveoli?

(1)High pO2, low pCO2, lesser H+, lower temperature

(2)Low pO2, high pCO2, high H+, higher temperature

(3)Low pO2, low pCO2, high H+, lower temperature

(4)High pO2, high pCO2, high H+, higher temperature

52.Which condition favours dissociation of O2 from oxyhaemoglobin in tissues?

(1)High pO2 and low pCO2

(2)Low pO2, high pCO2, high H+ and higher temperature

(3)High pO2, low H+ and lower temperature

(4)Low pCO2 and lower temperature

53.Under normal physiological conditions, every 100 mL oxygenated blood can deliver approximately how much O2 to tissues?

(1)3 mL

(2)4 mL

(3)5 mL

(4)7 mL

54.CO2 is carried by haemoglobin mainly as:

(1)Oxyhaemoglobin

(2)Carbamino-haemoglobin

(3)Carboxyhaemoglobin

(4)Carbonic acid only

55.Choose the correct statement:

(1)High pCO2 and low pO2 in tissues favour CO2 binding to haemoglobin.

(2)Low pCO2 and high pO2 in tissues favour CO2 binding to haemoglobin.

(3)High pCO2 and low pO2 in alveoli favour CO2 dissociation from haemoglobin.

(4)pO2 has no effect on CO2 binding to haemoglobin.

56.Carbonic anhydrase is present in highest concentration in:

(1)Plasma

(2)RBCs

(3)Pleural fluid

(4)Alveolar air

57.Which reaction is correctly facilitated by carbonic anhydrase?

(1)CO2 + H2O ⇌ H2CO3 ⇌ HCO3− + H+

(2)O2 + H2O ⇌ H2CO3 ⇌ HCO3− + H+

(3)CO2 + O2 ⇌ HCO3− + OH−

(4)HCO3− + O2 ⇌ CO2 + Hb

58.At tissue level, high pCO2 causes:

(1)CO2 to diffuse out of blood and form O2

(2)CO2 to diffuse into blood and form HCO3− and H+

(3)HCO3− to be converted only into O2

(4)Complete inhibition of carbonic anhydrase

59.At the alveolar site where pCO2 is low, the carbonic anhydrase reaction proceeds toward:

(1)Formation of HCO3− and H+ only

(2)Formation of CO2 and H2O

(3)Formation of oxyhaemoglobin only

(4)Permanent storage of CO2 as bicarbonate

60.Every 100 mL deoxygenated blood delivers approximately how much CO2 to alveoli?

(1)3 mL

(2)4 mL

(3)5 mL

(4)7 mL

61.Assertion A: O2 gets bound to haemoglobin at lung surface and dissociated at tissues.
Reason R: Alveoli have high pO2, low pCO2, lesser H+ and lower temperature; tissues show the opposite trend.

Choose the correct answer.

(1)Both A and R are true and R is the correct explanation of A.

(2)Both A and R are true but R is not the correct explanation of A.

(3)A is true but R is false.

(4)A is false but R is true.

62.Assertion A: CO2 can diffuse through the diffusion membrane more per unit partial pressure difference than O2.
Reason R: CO2 is 20-25 times more soluble than O2.

Choose the correct answer.

(1)Both A and R are true and R is the correct explanation of A.

(2)Both A and R are true but R is not the correct explanation of A.

(3)A is true but R is false.

(4)A is false but R is true.

63.The respiratory rhythm centre is primarily located in the:

(1)Cerebellum

(2)Medulla region of brain

(3)Pons region only

(4)Hypothalamus

64.Pneumotaxic centre is present in the:

(1)Medulla and primarily generates rhythm

(2)Pons and moderates respiratory rhythm centre

(3)Aortic arch and detects CO2 only

(4)Carotid artery and controls vocal cords

65.Choose the correct statements:
A. Pneumotaxic centre can reduce duration of inspiration.
B. Chemosensitive area adjacent to rhythm centre is sensitive to CO2 and H+.
C. Aortic arch and carotid artery receptors can detect changes in CO2 and H+.
D. Oxygen has the most significant role in regulation of respiratory rhythm.

(1)A, B and C only

(2)B, C and D only

(3)A and D only

(4)A, B, C and D

66.Increase in which substances activates the chemosensitive area to adjust respiratory process?

(1)O2 and glucose

(2)CO2 and H+

(3)N2 and O2

(4)Hb and bicarbonate only

67.Match:
(a) Respiratory rhythm centre (i) Aortic arch/carotid artery
(b) Pneumotaxic centre (ii) Medulla
(c) Chemosensitive area (iii) Pons
(d) Peripheral receptors (iv) Adjacent to rhythm centre; sensitive to CO2/H+

(1)a-ii, b-iii, c-iv, d-i

(2)a-iii, b-ii, c-iv, d-i

(3)a-ii, b-iv, c-iii, d-i

(4)a-i, b-iii, c-iv, d-ii

68.Asthma causes wheezing mainly due to inflammation of:

(1)Alveoli only

(2)Bronchi and bronchioles

(3)Pleural membranes only

(4)Diaphragm

69.Emphysema is characterised by:

(1)Damage to alveolar walls causing decrease in respiratory surface

(2)Inflammation of bronchi and bronchioles only

(3)Increase in pleural fluid friction

(4)Excess formation of tracheal cartilaginous rings

70.One major cause of emphysema mentioned in the PDF is:

(1)High altitude

(2)Cigarette smoking

(3)Excess water intake

(4)Vitamin deficiency

71.Which statements about occupational respiratory disorders are correct?
A. Grinding or stone-breaking industries can produce excessive dust.
B. Long exposure may cause inflammation leading to fibrosis.
C. Protective masks are advised for workers.
D. Fibrosis means reduction in fibrous tissue proliferation.

(1)A, B and C only

(2)B, C and D only

(3)A and D only

(4)A, B, C and D

72.Assertion A: The volume remaining in lungs after normal expiration is FRC.
Reason R: FRC includes ERV and RV.

Choose the correct answer.

(1)Both A and R are true and R is the correct explanation of A.

(2)Both A and R are true but R is not the correct explanation of A.

(3)A is true but R is false.

(4)A is false but R is true.

73.Assertion A: Contraction of diaphragm helps in inspiration.
Reason R: It increases thoracic volume, causing pulmonary volume to increase and intrapulmonary pressure to fall below atmospheric pressure.

Choose the correct answer.

(1)Both A and R are true and R is the correct explanation of A.

(2)Both A and R are true but R is not the correct explanation of A.

(3)A is true but R is false.

(4)A is false but R is true.

74.In the diagrammatic view of the human respiratory system, which labelled structure reduces friction on the lung surface?

(1)Pleural fluid

(2)Epiglottis

(3)Larynx

(4)Cut end of rib

75.In the respiratory-system diagram, the thin elastic flap that prevents food entry into the larynx is:

(1)Bronchiole

(2)Epiglottis

(3)Alveolus

(4)Diaphragm

76.In an alveolus-capillary section, which arrangement supports rapid gas diffusion?

(1)Thick muscular alveolar wall and thick cartilaginous capillary wall

(2)Thin squamous alveolar epithelium, capillary endothelium and very thin basement substance

(3)Multiple thick connective tissue layers and absence of capillaries

(4)Incomplete cartilaginous rings around alveoli

77.A sigmoid oxygen dissociation curve is useful mainly to study:

(1)Effect of pCO2 and H+ concentration on O2 binding with haemoglobin

(2)Only the anatomical position of the larynx

(3)Only the diameter of trachea at 5th thoracic vertebra

(4)The amount of pleural fluid

78.Which of the following is NOT a function of the conducting part?

(1)Transport atmospheric air to alveoli

(2)Clear air of foreign particles

(3)Humidify air and bring it to body temperature

(4)Actual diffusion of O2 and CO2 between blood and atmospheric air

79.Choose the correctly paired statement:

(1)Terminal bronchioles - exchange part

(2)Alveoli and ducts - conducting part

(3)Pons - pneumotaxic centre

(4)Oxygen - most significant regulator of respiratory rhythm

80.Which set contains only correctly matched NCERT numbers?

(1)TV 500 mL; breathing rate 12-16/min; O2 delivery 5 mL/100 mL blood; CO2 delivery 4 mL/100 mL blood

(2)TV 1000 mL; breathing rate 8-10/min; O2 delivery 4 mL/100 mL blood; CO2 delivery 5 mL/100 mL blood

(3)TV 500 mL; breathing rate 20-25/min; O2 by RBCs 70%; CO2 as bicarbonate 97%

(4)RV 500 mL; IRV 1000 mL; ERV 2500 mL; TV 1100 mL

Answer Key

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