Breathing and Exchange of Gases NEET PYQs (2005–2026) with Solutions

10 solved Breathing and Exchange of Gases PYQs

Real NEET and AIPMT questions from this chapter, newest first. Try each one, then open the answer and the step-by-step explanation.

1. Question 1 (NEET 2026)

   NEET 2026MediumMechanism of Breathing

   In humans, respiration occurs in the following steps. Arrange these steps in the correct order: A. Diffusion of O₂ and CO₂ between blood and tissues B. Diffusion of O₂ and CO₂ across alveolar membrane C. Pulmonary ventilation by which atmospheric air is drawn in and CO₂ rich alveolar air is released out D. Cellular respiration E. Transport of gases by the blood Choose the correct answer from the options given below:

   1. AOption A: A, B, C, D, E
   2. BOption B: E, A, C, D, B
   3. COption C: C, B, E, A, D
   4. DOption D: C, A, B, E, D

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   Correct answer: (C) C, B, E, A, D

   Explanation

   Respiration occurs in the sequence: pulmonary ventilation → diffusion across alveolar membrane → transport by blood → diffusion between blood and tissues → cellular respiration.

2. Question 2 (NEET 2026)

   NEET 2026MediumMechanism of Breathing

   Match List-I with List-II. Choose the correct answer from the options given below :

   1. AOption A: A-III, B-IV, C-I, D-II
   2. BOption B: A-III, B-I, C-IV, D-II
   3. COption C: A-I, B-III, C-II, D-IV
   4. DOption D: A-I, B-II, C-III, D-IV

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   Correct answer: (A) A-III, B-IV, C-I, D-II

   Explanation

   ERV = 1000–1100 mL, RV = 1100–1200 mL, IRV = 2500–3000 mL and TV = 500 mL.

3. Question 3 (NEET 2026)

   NEET 2026EasyRespiratory organs in animals

   Sponges exchange $\mathrm{O_2}$ with $\mathrm{CO_2}$ by __________.

   1. AOption A: simple diffusion over their entire body surfaces
   2. BOption B: moist cuticle
   3. COption C: tracheal tubes
   4. DOption D: gills

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   Correct answer: (A) simple diffusion over their entire body surfaces

   Explanation

   NCERT states that lower invertebrates like sponges, coelenterates and flatworms exchange $\mathrm{O_2}$ with $\mathrm{CO_2}$ by simple diffusion over their entire body surface. Earthworms use their moist cuticle, insects have a network of tracheal tubes, and most aquatic arthropods and molluscs use gills. So sponges use simple diffusion over the entire body surface, option (A).

4. Question 4 (NEET 2024)

   NEET 2024EasyGas Transport

   Which of the following factors are favourable for the formation of oxyhaemoglobin in alveoli?

   1. AOption A: Low pCO₂ and High H⁺ concentration
   2. BOption B: Low pCO₂ and High temperature
   3. COption C: High pO₂ and High pCO₂
   4. DOption D: High pO₂ and Lesser H⁺ concentration

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   Correct answer: (D) High pO₂ and Lesser H⁺ concentration

   Explanation

   Formation of oxyhaemoglobin is favored by high partial pressure of oxygen, low partial pressure of carbon dioxide, lower H⁺ concentration (higher pH), and lower temperature. Therefore, high pO₂ and lesser H⁺ concentration are the correct conditions.

5. Question 5 (NEET 2024)

   NEET 2024MediumMechanism of Breathing

   Match List I with List II : Choose the correct answer from the options given below:

   1. AOption A: A-II, B-I, C-IV, D-III
   2. BOption B: A-I, B-III, C-II, D-IV
   3. COption C: A-II, B-IV, C-I, D-III
   4. DOption D: A-III, B-II, C-IV, D-I

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   Correct answer: (C) A-II, B-IV, C-I, D-III

   Explanation

   Expiratory reserve capacity corresponds to expiratory reserve volume. Functional residual capacity equals expiratory reserve volume plus residual volume. Vital capacity equals inspiratory reserve volume + tidal volume + expiratory reserve volume. Inspiratory capacity equals tidal volume + inspiratory reserve volume. Hence the correct match is A-II, B-IV, C-I, D-III.

6. Question 6 (NEET 2022)

   NEET 2022MediumRespiratory Organs

   Which of the following is not the function of conducting part of respiratory system?

   1. AOption A: Provides surface for diffusion of O₂ and CO₂
   2. BOption B: It clears inhaled air from foreign particles
   3. COption C: Inhaled air is humidified
   4. DOption D: Temperature of inhaled air is brought to body temperature

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   Correct answer: (A) Provides surface for diffusion of O₂ and CO₂

   Explanation

   Gas exchange occurs in alveoli (respiratory part), not in the conducting part. Conducting passages filter, humidify and warm inhaled air.

7. Question 7 (NEET 2022)

   NEET 2022MediumGas Transport

   Under normal physiological conditions in human beings every 100 ml of oxygenated blood can deliver ______ ml of O₂ to the tissues.

   1. AOption A: 10 ml
   2. BOption B: 2 ml
   3. COption C: 5 ml
   4. DOption D: 4 ml

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   Correct answer: (C) 5 ml

   Explanation

   Approximately 5 ml O₂ per 100 ml oxygenated blood is delivered to tissues under normal physiological conditions.

8. Question 8 (NEET 2021)

   NEET 2021MediumGas Transport

   The partial pressures (in mm Hg) of oxygen (O₂) and carbon dioxide (CO₂) at alveoli (the site of diffusion) are:

   1. AOption A: pO₂ = 159 and pCO₂ = 0.3
   2. BOption B: pO₂ = 104 and pCO₂ = 40
   3. COption C: pO₂ = 40 and pCO₂ = 45
   4. DOption D: pO₂ = 95 and pCO₂ = 40

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   Correct answer: (B) pO₂ = 104 and pCO₂ = 40

   Explanation

   At alveoli, partial pressures are approximately pO₂ = 104 mm Hg and pCO₂ = 40 mm Hg.

9. Question 9 (NEET 2021)

   NEET 2021HardGas Transport

   Select the favourable conditions required for the formation of oxyhaemoglobin at the alveoli.

   1. AOption A: Low pO₂, low pCO₂, more H⁺, higher temperature
   2. BOption B: High pO₂, low pCO₂, less H⁺, lower temperature
   3. COption C: Low pO₂, high pCO₂, more H⁺, higher temperature
   4. DOption D: High pO₂, high pCO₂, less H⁺, higher temperature

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   Correct answer: (B) High pO₂, low pCO₂, less H⁺, lower temperature

   Explanation

   Formation of oxyhaemoglobin in alveoli is favoured by high partial pressure of oxygen (pO₂), low pCO₂, lower H⁺ concentration and lower temperature.

10. Question 10 (NEET 2018)

    NEET 2018EasyRespiratory disorders

    Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively?

    1. AOption A: Inflammation of bronchioles; Decreased respiratory surface
    2. BOption B: Increased number of bronchioles; Increased respiratory surface
    3. COption C: Decreased respiratory surface; Inflammation of bronchioles
    4. DOption D: Increased respiratory surface; Inflammation of bronchioles

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    Correct answer: (A) Inflammation of bronchioles; Decreased respiratory surface

    Explanation

    Asthma is a respiratory disorder characterized by inflammation and narrowing of bronchioles, causing difficulty in breathing. Emphysema is a chronic disorder in which the alveolar walls are damaged, resulting in decreased respiratory surface area. Hence, option (A) is correct.