Q1. Assertion: Vital Capacity is higher than Tidal Volume.
Reason: Vital Capacity includes ERV, TV, and IRV.
Correct Answer: (a)
Summation of multiple volumes makes the capacity larger.
Q2. Match the partial pressure in mm Hg (Blood Deoxygenated):
Gas
pO2/pCO2
A. O2
(I) 45
B. CO2
(II) 40
Correct Answer: (a)
Deoxy blood: pO2=40, pCO2=45.
Q3. Regarding 'Pleura', which is true? (i) Double layered membrane covering lungs. (ii) Contains pleural fluid. (iii) Outer layer in contact with thoracic lining.
Correct Answer: (a)
Description from section 14.1.1.
Q4. Assertion: Haemoglobin can carry a maximum of four molecules of O2.
Reason: Haemoglobin is a red coloured iron containing pigment.
Correct Answer: (a)
Both are true, but the color/iron doesn't explain the 'four molecules' stoichiometric capacity.
Q8. The partial pressure of oxygen (pO2) in the alveoli is ______ mm Hg.
Correct Answer: (b)
As per Table 14.1, pO2 in alveoli is 104 mm Hg.
Q9. Assertion: Expiration occurs when intra-pulmonary pressure is higher than atmospheric pressure.
Reason: Relaxation of the diaphragm and intercostal muscles reduces thoracic volume.
Correct Answer: (a)
Relaxation causes volume decrease, which increases pressure and forces air out.
Q10. The respiratory rhythm centre is primarily located in the ______ region of the brain.
Correct Answer: (c)
A specialized centre in the medulla called the respiratory rhythm centre is primarily responsible for regulation.
Q11. Assertion: The role of oxygen in the regulation of respiratory rhythm is quite insignificant.
Reason: Respiratory rhythm is mainly regulated by CO2 and H+ concentration.
Correct Answer: (a)
The neural centers and chemosensitive areas prioritize CO2 and pH over O2 levels.
Q12. Assertion: RBCs are nucleated in some organisms but not mammals.
Reason: Mature human erythrocytes lack a nucleus.
Correct Answer: (a)
Human RBCs being non-nucleated is a specific fact, but doesn't explain the state of other organisms.
Q13. The cartilaginous box in the human respiratory system which helps in sound production is the:
Correct Answer: (c)
Larynx is a cartilaginous box which helps in sound production and hence called the sound box.
Q14. The trachea divides into right and left primary bronchi at the level of which vertebra?
Correct Answer: (b)
Trachea divides at the level of the 5th thoracic vertebra.
Q15. Assertion: Diffusion of gases occurs in the alveolar region only.
Reason: Alveoli and their ducts form the exchange part of the respiratory system.
Correct Answer: (a)
Exchange only happens in the exchange part (alveoli).
Q16. Match the organism in Column-I with its respiratory organ in Column-II:
Q18. Which of the following is being described by the given statements? (i) These are located in the thoracic chamber. (ii) They are covered by a double layered pleura. (iii) Their total volume can be Accommodation in the end of forced inspiration.
Correct Answer: (b)
These describe the location, covering, and capacity (TLC) of the lungs.
Q19. Assertion: A sigmoid curve is obtained when percentage saturation of haemoglobin with O2 is plotted against pO2.
Reason: Sigmoid curve indicates that binding of the first O2 molecule facilitates the binding of others.
Correct Answer: (b)
Both are true, but the NCERT text only provides the fact of the curve, not the chemical cooperativity reason explicitly.
Q20. Match the transport mechanism with the percentage of gas:
Column-I (Gas & State)
Column-II (Percentage)
A. O2 by RBCs
(I) 70%
B. O2 in dissolved plasma
(II) 20-25%
C. CO2 as Bicarbonate
(III) 97%
D. CO2 by RBCs
(IV) 3%
Correct Answer: (a)
O2 RBC: 97%; O2 Plasma: 3%; CO2 Bicarb: 70%; CO2 RBC: 20-25%.
Q21. The volume of air involved in breathing movements can be estimated using a:
Correct Answer: (b)
A spirometer helps in clinical assessment of pulmonary functions.
Q22. The site of actual diffusion of O2 and CO2 between blood and atmospheric air is the:
Correct Answer: (b)
Exchange part is the site of actual diffusion of O2 and CO2.
Q23. The chemosensitive area adjacent to the rhythm centre is highly sensitive to:
Correct Answer: (b)
The chemosensitive area is highly sensitive to CO2 and hydrogen ions.
Q24. Assertion: Emphysema is a chronic disorder.
Reason: One of the major causes is cigarette smoking.
Correct Answer: (b)
Cigarette smoking causes the damage, which makes it chronic.
Q25. Branchial respiration refers to the use of:
Correct Answer: (c)
Respiration using gills is called branchial respiration.
Q26. During swallowing, the entry of food into the larynx is prevented by a thin elastic cartilaginous flap called:
Correct Answer: (b)
Epiglottis prevents the entry of food into the larynx.
Q27. Functional Residual Capacity (FRC) includes:
Correct Answer: (b)
FRC includes ERV + RV.
Q28. Assertion: The conducting part clears the air from foreign particles.
Reason: It includes the nostrils up to the terminal bronchioles.
Correct Answer: (b)
Both are true, but its extent doesn't explain how it clears particles (which is done by mucus/cilia).
Q29. Identify correct matches for 'Volumes': (i) TV = 500 mL. (ii) RV = 1100-1200 mL. (iii) VC = TV + IRV + ERV.
Correct Answer: (a)
Standard volumes and VC formula.
Q30. Occupational respiratory disorders like fibrosis are caused by long exposure to:
Correct Answer: (c)
Industries involving grinding or stone-breaking produce dust that causes fibrosis.
Q31. Match the partial pressure (Atmosphere):
Gas
mm Hg
A. O2
(I) 0.3
B. CO2
(II) 159
Correct Answer: (a)
Atmos air: pO2=159, pCO2=0.3.
Q32. The diffusion membrane is made up of how many major layers?
Correct Answer: (c)
The diffusion membrane is made up of three major layers: squamous epithelium, endothelium, and basement substance.
Q33. Which statements about 'Alveoli' are correct? (i) Site of gas exchange. (ii) Surrounded by network of capillaries. (iii) Have thin squamous epithelium.
Correct Answer: (a)
Standard alveolar anatomy and role.
Q34. Regarding 'Oxygen Dissociation Curve', identify correct statements: (i) It is sigmoid shaped. (ii) Plot of % saturation of Hb with O2 vs pO2. (iii) High H+ shift it to the right (dissociation).
Correct Answer: (a)
High H+ and pCO2 favor dissociation, shifting curve to right.
Q35. Match the component of the diffusion membrane (Inside to Outside):
Layer
Name
A. Layer 1
(I) Squamous epithelium of alveoli
B. Layer 2
(II) Endothelium of alveolar capillaries
C. Layer 3
(III) Basement substance
Correct Answer: (a)
Correct layers of diffusion membrane as per section 14.3.
Q36. Which muscles, along with the diaphragm, help in generation of pressure gradients for breathing?
Correct Answer: (c)
The diaphragm and intercostal muscles help in generating pressure gradients.
Q37. Regarding 'Expiratory Reserve Volume' (ERV): (i) Additional volume of air a person can expire forcibly. (ii) Average 1000 to 1100 mL. (iii) It is always larger than IRV.
Correct Answer: (a)
IRV (2500-3000) is much larger than ERV (1000-1100).
Q38. Identify correct steps in 'Respiration': (i) Breathing. (ii) Diffusion across alveolar membrane. (iii) Transport by blood. (iv) Utilization of O2 by cells.
Correct Answer: (a)
Sequence of events from section 14.1.1 list.
Q39. Which are correct for 'Larynx'? (i) Cartilaginous box. (ii) Helps in sound production. (iii) Called the sound box.
Correct Answer: (a)
Structure and function of larynx.
Q40. Lungs are covered by a double-layered membrane called:
Correct Answer: (c)
Lungs are covered by a double layered pleura.
Q41. Match the partial pressure of O2 (pO2) with the site (Table 14.1):
Q42. Which of the following is true for 'Solubility'? (i) CO2 is more soluble than O2. (ii) Solubility is 20-25 times higher. (iii) This increases CO2 diffusion rate across membranes.
Correct Answer: (a)
Relationship between solubility and diffusion.
Q44. Which group of animals exchanges O2 and CO2 by simple diffusion over their entire body surface?
Correct Answer: (c)
Lower invertebrates like sponges, coelenterates, and flatworms use simple diffusion over their body surface.
Q45. The lungs are situated in an air-tight chamber called the:
Correct Answer: (b)
The lungs are situated in the thoracic chamber.
Q46. Assertion: Trachea is supported by incomplete cartilaginous rings.
Reason: It prevents the trachea from collapsing.
Correct Answer: (b)
Both are true (functional anatomy), but not explicitly detailed as the reason in the provided snippet.
Q47. Assertion: Tidal volume is about 500 mL.
Reason: It is the volume of air inspired or expired during a normal respiration.
Correct Answer: (a)
The definition explains the volume.
Q48. Assertion: Solubility of CO2 is 20-25 times higher than that of O2.
Reason: The amount of CO2 that can diffuse through the diffusion membrane per unit difference in partial pressure is much higher.
Correct Answer: (a)
High solubility directly correlates to high diffusion rate across the membrane.
Q49. Select correct statements for 'Regulation of Respiration': (i) Respiratory rhythm centre is in medulla. (ii) Pneumotaxic centre is in pons. (iii) O2 has a major role in regulation.
Correct Answer: (a)
O2 role (iii) is insignificant.
Q50. Regarding 'Partial Pressure', which is true? (i) pO2 in alveoli is 104 mm Hg. (ii) pCO2 in alveoli is 40 mm Hg. (iii) pO2 in oxygenated blood is 95 mm Hg.
Correct Answer: (a)
All values match Table 14.1.
Q51. Identify the correct phylum/group being described: (i) High pO2, low pCO2 in alveoli. (ii) Low pO2, high pCO2 in tissues. (iii) Diffusion occurs along concentration gradients.
Correct Answer: (a)
Conditions favoring diffusion are part of gas exchange.
Q52. The branching network of bronchi, bronchioles, and ______ comprise the lungs.
Correct Answer: (b)
The branching network of bronchi, bronchioles and alveoli comprise the lungs.
Q53. Which of the following describes 'Asthma' correctly? (i) Difficulty in breathing. (ii) Causes wheezing. (iii) Due to inflammation of bronchi and bronchioles.
Correct Answer: (a)
Full clinical description of asthma provided.
Q54. Assertion: The diffusion membrane is less than a millimetre thick.
Reason: All factors in our body are favourable for diffusion of O2 from alveoli to tissues.
Correct Answer: (a)
Thickness is a factor, and diffusion is favorable, but 'thickness' is only one of the factors.
Q55. Match the scientists' focus:
Scientist
Discovery
A. Alfonso Corti
(I) Basilar membrane hair cells
B. Blackman
(II) Law of limiting factors (Unit Intro)
Correct Answer: (a)
Historical contributions mentioned in unit/chapter.
Q57. Emphysema is a chronic disorder primarily caused by:
Correct Answer: (b)
One of the major causes of emphysema is cigarette smoking.
Q58. Assertion: Occupational respiratory disorders cause serious lung damage.
Reason: Long exposure to dust can lead to fibrosis (proliferation of fibrous tissues).
Correct Answer: (a)
Fibrosis reduces lung function and is the pathological cause of damage in these disorders.
Q59. Inspiration occurs when there is a ______ pressure in the lungs with respect to atmospheric pressure.
Correct Answer: (b)
Inspiration occurs if there is a negative pressure in the lungs with respect to atmospheric pressure.
Q60. Match the O2 delivery factors:
Factor
Effect on Hb Binding
A. High pO2
(I) Favour binding
B. High pCO2
(II) Favour dissociation
C. High H+
(III) Favour dissociation
Correct Answer: (a)
Conditions in Alveoli (I) vs Tissues (II/III).
Q61. Tracheal tubes as a respiratory mechanism are found in:
Correct Answer: (b)
Insects have a network of tubes (tracheal tubes) to transport atmospheric air within the body.
Q62. Identify the correct features of the 'Diffusion Membrane': (i) Thin squamous epithelium of alveoli. (ii) Endothelium of alveolar capillaries. (iii) Total thickness is much less than a millimetre.
Correct Answer: (a)
Anatomical components and thickness of the membrane.
Q63. Assertion: Every 100 ml of oxygenated blood can deliver around 5 ml of O2 to the tissues.
Reason: Oxyhaemoglobin is formed in the alveoli and dissociates in the tissues.
Correct Answer: (a)
The delivery of O2 is a result of the formation and subsequent dissociation of oxyhaemoglobin.
Q64. Every 100 ml of deoxygenated blood delivers approximately ______ ml of CO2 to the alveoli.
Correct Answer: (a)
Every 100 ml of deoxygenated blood delivers approximately 4 ml of CO2 to the alveoli.
Q65. Match the volumes in sequence of size (Smallest to Largest):
Rank
Volume
1st
TV (500)
2nd
ERV (1000-1100)
3rd
RV (1100-1200)
4th
IRV (2500-3000)
Correct Answer: (a)
Standard volume ranges in mL.
Q66. Which statement about 'Conducting Part' is correct? (i) It consists of nostrils to terminal bronchioles. (ii) It is the site of actual diffusion of O2 and CO2. (iii) It clears air from foreign particles.
Correct Answer: (a)
Diffusion (ii) happens in the exchange part, not conducting part.
Q67. On average, a healthy human breathes ______ times per minute.
Correct Answer: (b)
On an average, a healthy human breathes 12-16 times/minute.
Q68. The solubility of CO2 is ______ times higher than that of O2.
Correct Answer: (c)
The solubility of CO2 is 20-25 times higher than that of O2.
Q69. Assertion: Carbonic anhydrase is found in RBCs and plasma.
Reason: It helps in the conversion of CO2 and water to bicarbonate.
Correct Answer: (a)
The enzyme's presence allows the specific chemical transport mechanism.
Q70. The 'Organ of Corti' is located on which membrane of the cochlea?
Correct Answer: (b)
Corti described a structure located on the basilar membrane of the cochlea.
Q71. Which of the following is correct? (i) RBCs carry 97% O2. (ii) RBCs carry 20-25% CO2. (iii) RBCs contain carbonic anhydrase.
Correct Answer: (a)
The roles and enzymatic content of RBCs in gas transport.
Q72. Assertion: Inspiration is initiated by the contraction of diaphragm.
Reason: Contraction of the diaphragm increases the volume of the thoracic chamber in the dorso-ventral axis.
Correct Answer: (c)
Reason is false because diaphragm contraction increases volume in the antero-posterior axis, not dorso-ventral.
Q73. Assertion: Alveoli are the primary sites of exchange of gases.
Reason: They are irregular-walled and vascularised bag-like structures.
Correct Answer: (b)
Both are true descriptions, but its structure is not the only reason it's the 'primary site' (exchange also occurs at tissues).
Q74. Which statements about 'Epiglottis' are correct? (i) Thin elastic cartilaginous flap. (ii) Prevents entry of food into larynx. (iii) Covers glottis during swallowing.
Correct Answer: (a)
Function and structure of the epiglottis.
Q75. The partial pressure of CO2 (pCO2) in deoxygenated blood is:
Correct Answer: (b)
As per Table 14.1, pCO2 in deoxygenated blood is 45 mm Hg.
Q76. Match the vertebrate with its respiratory organ:
Q77. Assertion: CO2 diffuses from tissues to blood.
Reason: pCO2 is higher in tissues (45 mm Hg) than in deoxygenated blood (40 mm Hg is incorrect; it's 45).
Correct Answer: (a)
Deoxy blood and tissues have the same pCO2 (45), but tissues are the source, so it moves to blood.
Q78. Vital Capacity (VC) is the sum of:
Correct Answer: (c)
Vital Capacity includes ERV, TV and IRV.
Q79. What percentage of O2 is transported by RBCs in the blood?
Correct Answer: (d)
About 97 per cent of O2 is transported by RBCs.
Q80. Which disorder is characterized by inflammation of bronchi and bronchioles causing wheezing?
Correct Answer: (b)
Asthma is a difficulty in breathing caused by inflammation of bronchi and bronchioles.
Q81. Which of the following vertebrates uses gills for respiration?
Correct Answer: (c)
Among vertebrates, fishes use gills.
Q82. Tidal Volume (TV) for a healthy man is approximately ______ mL per minute.
Correct Answer: (c)
A healthy man can inspire or expire approximately 6000 to 8000 mL of air per minute.
Q83. Regarding 'Haemoglobin' binding: (i) Favouring factors in alveoli: High pO2, low pCO2, low H+, lower temp. (ii) Favouring dissociation in tissues: Low pO2, high pCO2, high H+, high temp.
Correct Answer: (a)
Environmental conditions for Hb-O2 affinity.
Q84. Match the partial pressure of CO2 (pCO2) with the site (Table 14.1):