Different animal groups exchange gases through structures suited to their habitat and level of organisation. Lower invertebrates rely on simple diffusion across the body surface; earthworms use their moist, vascularised cuticle; insects have a branching tracheal system opening to the outside through spiracles; fish use gills to extract dissolved oxygen from water; and amphibians co
Breathing and Exchange of Gases
Class 1113 previous-year questions from this chapter every option and the correct answer, free · where the marks are
1. Respiratory organs and mechanism of breathing
Exam focus: Quiet breathing is not two mirrored active steps: inspiration is active (the diaphragm contracts and flattens, intercostals lift the ribs, thoracic volume rises), but normal expiration is passive, driven by elastic recoil once those muscles relax. Only forced expiration calls in the internal intercostals and abdominal muscles — the detail NEET's active-or-passive options hinge on.
Breathing and Exchange of Gases — Full Chapter (Respiratory Organs and Mechanism of Breathing)
PW NEET
Full-chapter one-shot; early sections cover respiratory organs, the human respiratory system, lungs, and the mechanism of breathing (inhalation/exhalation, volumes/capacities).
ZoologyNEET 2024show ▾Match List I with List II.
List I List II A. Expiratory capacity I. Expiratory reserve volume + Tidal volume + Inspiratory reserve volume B. Functional residual capacity II. Tidal volume + Expiratory reserve volume C. Vital capacity III. Tidal volume + Inspiratory reserve volume D. Inspiratory capacity IV. Expiratory reserve volume + Residual volume
Choose the correct answer from the options given below:
- A.A-III, B-II, C-IV, D-I
- B.A-II, B-I, C-IV, D-III
- C.A-I, B-III, C-II, D-IV
- D.A-II, B-IV, C-I, D-III✓
Solution
Expiratory capacity (II); functional residual capacity (IV); vital capacity (I); inspiratory capacity (III).
Open this question on its own page →
Save for spaced revision (free account)ZoologyNEET 2023show ▾The vital capacity of the lung is _________.
- A.IRV + ERV
- B.IRV + ERV + TV + RV
- C.IRV + ERV + TV – RV
- D.IRV + ERV + TV✓
The worked solution is part of a paid pack.
ZoologyNEET 2022show ▾Which of the following is not a function of the conducting part of the respiratory system?
- A.Provides surface for diffusion of and ✓
- B.It clears inhaled air of foreign particles
- C.Inhaled air is humidified
- D.Temperature of inhaled air is brought to body temperature
The worked solution is part of a paid pack.
ZoologyNEET 2020show ▾Select the correct events that occur during inspiration.
(a) Contraction of the diaphragm
(b) Contraction of the external inter-costal muscles
(c) Pulmonary volume decreases
(d) Intra-pulmonary pressure increases
- A.(a) and (b)✓
- B.(c) and (d)
- C.(a), (b) and (d)
- D.Only (d)
The worked solution is part of a paid pack.
ZoologyNEET 2019show ▾The Tidal Volume and Expiratory Reserve Volume of an athlete are 500 mL and 1000 mL, respectively. What will be his Expiratory Capacity if the Residual Volume is 1200 mL?
- A.1500 mL✓
- B.1700 mL
- C.2200 mL
- D.2700 mL
The worked solution is part of a paid pack.
2. Exchange and transport of gases
Exam focus: The percentages NEET likes to swap: of the CO2 carried in blood, about 70% travels as bicarbonate and only 20-25% as carbaminohaemoglobin, the reverse of how most students remember it. For O2, the Bohr effect — more CO2, more H+, lower pH, higher temperature in the tissues — shifts the dissociation curve right, making haemoglobin release more oxygen exactly where it's needed.
Breathing and Exchange of Gases — Full Chapter (Exchange and Transport of Gases)
PW NEET
Same one-shot; its middle sections cover gas exchange at the alveoli/capillary, the O2 dissociation curve, and CO2 transport.
ZoologyNEET 2024show ▾Which of the following factors are favourable for the formation of oxyhaemoglobin in the alveoli?
- A.High and lesser concentration✓
- B.Low and high concentration
- C.Low and high temperature
- D.High and high
Solution
In the alveoli, high , low , lower concentration and lower temperature all favour binding of oxygen to haemoglobin.
Open this question on its own page →
Save for spaced revision (free account)ZoologyNEET 2022show ▾Under normal physiological conditions in human beings, every 100 mL of oxygenated blood can deliver ______ mL of to the tissues.
- A.10 mL
- B.2 mL
- C.5 mL✓
- D.4 mL
The worked solution is part of a paid pack.
ZoologyNEET 2021show ▾The partial pressures (in mm Hg) of oxygen () and carbon dioxide () at the alveoli (the site of diffusion) are:
- A. = 104 and = 40✓
- B. = 40 and = 45
- C. = 95 and = 40
- D. = 159 and = 0.3
The worked solution is part of a paid pack.
ZoologyNEET 2021show ▾Select the favourable conditions required for the formation of oxyhaemoglobin at the alveoli.
- A.High , low , less , lower temperature✓
- B.Low , high , more , higher temperature
- C.High , high , less , higher temperature
- D.Low , low , more , higher temperature
The worked solution is part of a paid pack.
ZoologyNEET 2020show ▾Identify the wrong statement with reference to the transport of oxygen.
- A.Binding of oxygen with haemoglobin is mainly related to the partial pressure of
- B.Partial pressure of can interfere with binding to haemoglobin
- C.A higher concentration in the alveoli favours the formation of oxyhaemoglobin✓
- D.Low in the alveoli favours the formation of oxyhaemoglobin
The worked solution is part of a paid pack.
3. Regulation and disorders
Exam focus: Breathing rate is regulated mainly by CO2 and H+ levels sensed by the medulla's chemosensitive area, not by how much O2 is available — the opposite of the intuitive "we breathe because we need oxygen." Among disorders, emphysema is alveolar-wall damage that shrinks the gas-exchange surface (usually from chronic smoking), while asthma is inflammation of the bronchi and bronchioles causing wheezing, not alveolar damage.
Breathing and Exchange of Gases — Full Chapter (Regulation and Disorders)
PW NEET
Same one-shot; final sections cover nervous/chemical regulation of respiration and respiratory disorders.
BotanyNEET 2025show ▾Match List I with List II.
List I List II A. Emphysema I. Rapid spasms in muscle due to low in body fluid B. Angina pectoris II. Damaged alveolar walls and decreased respiratory surface C. Glomerulonephritis III. Acute chest pain when not enough oxygen is reaching the heart muscle D. Tetany IV. Inflammation of the glomeruli of the kidney
Choose the correct answer from the options given below:
- A.A-III, B-I, C-IV, D-II
- B.A-III, B-I, C-II, D-IV
- C.A-II, B-IV, C-III, D-I
- D.A-II, B-III, C-IV, D-I✓
Solution
Emphysema: damaged alveolar walls and reduced respiratory surface (II). Angina pectoris: acute chest pain from an under-supplied heart muscle (III). Glomerulonephritis: inflammation of the glomeruli (IV). Tetany: rapid muscle spasms from low (I).
Open this question on its own page →
Save for spaced revision (free account)ZoologyNEET 2021show ▾Assertion (A): A person goes to high altitude and experiences 'altitude sickness' with symptoms like breathing difficulty and heart palpitations.
Reason (R): Due to low atmospheric pressure at high altitude, the body does not get sufficient oxygen.
In the light of the above statements, choose the correct answer from the options given below:
- A.Both (A) and (R) are true and (R) is the correct explanation of (A)✓
- B.Both (A) and (R) are true but (R) is not the correct explanation of (A)
- C.(A) is true but (R) is false
- D.(A) is false but (R) is true
The worked solution is part of a paid pack.
ZoologyNEET 2019show ▾Due to increasing air-borne allergens and pollutants, many people in urban areas suffer from a respiratory disorder causing wheezing, due to:
- A.Benign growth on the mucous lining of the nasal cavity
- B.Inflammation of the bronchi and bronchioles✓
- C.Proliferation of fibrous tissue and damage to the alveolar walls
- D.Reduction in the secretion of surfactants by pneumocytes
The worked solution is part of a paid pack.