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The topic of Breathing and Exchange of Gases is an important chapter in the NEET syllabus, often featured in the exam. Understanding the key concepts of how organisms take in oxygen and expel carbon dioxide is crucial for scoring well. Many students prepare by solving breathing and exchange of gases NEET questions with answers, as these help them grasp the fundamental mechanisms involved in respiration. For comprehensive preparation, students can access breathing and exchange of gases NEET questions with answers PDF free, which are readily available online. These resources, including mock tests, provide valuable practice, ensuring students are ready for the upcoming NEET exam 2025. If you’re looking for specific practice material, you can find breathing and exchange of gases NEET questions PDFs for download, offering targeted practice to ace this topic.
Breathing and Exchange of Gases NEET Questions with Answers
Preparing for the Breathing and Exchange of Gases section is crucial for acing the NEET exam. To help you, we have compiled a comprehensive list of Breathing and Exchange of Gases NEET Questions with Answers. These questions cover essential concepts and can be downloaded as a Breathing and Exchange of Gases NEET Questions PDF for free. Additionally, students can attempt mock tests to get a better grasp of the topic and be well-prepared for NEET 2025.
Top 10 Important Breathing and Exchange of Gases NEET Questions and Answers
Here are the Top 10 Important Breathing and Exchange of Gases NEET Questions and Answers to help you prepare effectively for your exam. These questions cover key concepts and are crucial for mastering this chapter. You can also find detailed explanations to ensure a deeper understanding, making it easier to tackle similar questions in NEET.
1. Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration, because of:
- A. Expiratory reserve volume
- B. Inspiratory reserve volume
- C. Residual volume
- D. Tidal volume
Answer: The correct answer is C. Residual volume.
Explanation: Residual volume refers to the amount of air that remains in the lungs even after a forceful expiration. This air helps keep the alveoli from collapsing.
2. Lungs do not collapse between breaths and some air always remains in the lungs which can never be expelled because:
- A. There is a positive intrapleural pressure
- B. There is negative intrapleural pressure pulling at the lung walls
- C. There is negative pressure in the lungs
- D. Pressure in the lungs is higher than the atmospheric pressure
Answer: The correct answer is B. There is negative intrapleural pressure pulling at the lung walls.
Explanation: Negative intrapleural pressure helps to keep the lungs expanded and prevents them from collapsing between breaths.
3. Name the chronic respiratory disorder caused mainly by cigarette smoking:
- A. Respiratory Alkalosis
- B. Respiratory Acidosis
- C. Asthma
- D. Emphysema
Answer: The correct answer is D. Emphysema.
Explanation: Emphysema is a chronic lung condition often caused by smoking, where the alveoli are damaged, leading to difficulty in breathing.
4. Approximately 70% of carbon dioxide absorbed by the blood will be transported to the lungs:
- A. As carbamino hemoglobin
- B. By binding to RBCs
- C. In the form of dissolved gas molecules
- D. As bicarbonate ions
Answer: The correct answer is D. As bicarbonate ions.
Explanation: The majority of carbon dioxide in the blood is converted to bicarbonate ions, which are then transported to the lungs for exhalation.
5. People who have migrated from the plains to an area adjoining Rohtang pass about 6 months back:
- A. Are not physically fit to play games like football
- B. Have more RBCs and their hemoglobin has a lower binding affinity to O2
- C. Have the usual RBC count, but their hemoglobin has very high binding affinity to O2
- D. Suffer from altitude sickness with symptoms like nausea, fatigue, etc.
Answer: The correct answer is B. Have more RBCs and their hemoglobin has a lower binding affinity to O2.
Explanation: At high altitudes, the body adapts by increasing RBC count to improve oxygen transport, though the hemoglobin’s affinity for oxygen decreases to facilitate better oxygen release to tissues.
6. A large proportion of oxygen remains unused in the human blood even after its uptake by the body tissue. This O2:
- A. Helps in releasing more O2 to the epithelial tissues
- B. Is enough to keep oxyhemoglobin saturation at 96%
- C. Raises the pCO2 of blood to 75mm of Hg
- D. Acts as a reserve during muscular exercise
Answer: The correct answer is D. Acts as a reserve during muscular exercise.
Explanation: The oxygen that remains in the blood acts as a reserve, especially useful during physical activities when the body requires more oxygen.
7. Bulk of carbon dioxide (CO2) released from body tissues into the blood is present as:
- A. Carbamino-hemoglobin in RBCs
- B. 70% carbamino-hemoglobin and 30% as bicarbonate
- C. Free CO2 in blood plasma
- D. Bicarbonate in blood plasma and RBCs
Answer: The correct answer is D. Bicarbonate in blood plasma and RBCs.
Explanation: Most of the carbon dioxide produced in the tissues is converted into bicarbonate ions and transported in the blood.
8. What is true about RBCs in humans?
- A. They transport about 80% oxygen only and the rest 20% of it is transported in the dissolved state in blood plasma
- B. They transport 99.5% of O2
- C. They carry about 20-25% of CO2
- D. They do not carry CO2 at all
Answer: The correct answer is C. They carry about 20-25% of CO2.
Explanation: RBCs transport about 20-25% of carbon dioxide by binding it to hemoglobin, forming carbamino-hemoglobin.
9. 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: The correct answer is C. Has a higher affinity for oxygen than that of an adult.
Explanation: Fetal hemoglobin has a higher affinity for oxygen to effectively extract oxygen from the mother’s blood.
10. Pick the incorrect statement:
- A. The presence of non-respiratory air sacs increases the efficiency of respiration in birds
- B. The residual air in the lungs slightly decreases the efficiency of respiration in mammals
- C. The principle of counter-current flow facilitates efficient respiration in gills of fishes
- D. In insects, circulating body fluids serve to distribute oxygen to tissues
Answer: The correct answer is D. In insects, circulating body fluids serve to distribute oxygen to tissues.
Explanation: Insects do not rely on circulating body fluids (hemolymph) to transport oxygen. Instead, they use a tracheal system for gas exchange.
Breathing and Exchange of Gases NEET Questions PYQ (Appeared in NEET 2024)
Question 1:
Assertion (A): During the transportation of gases, about 20-25% of CO₂ is carried by Hemoglobin as carbamino-hemoglobin.
Reason (R): This binding is related to high pCO₂ and low pO₂ in tissues.
In light of the above statements, choose the correct answer from the options given below:
- A. A is true but R is false.
- B. A is false but R is true.
- C. Both A and R are true and R is the correct explanation of A.
- D. Both A and R are true but R is NOT the correct explanation of A.
Answer: C
Explanation: Both the assertion and the reason are correct, and the reason accurately explains why Hemoglobin carries CO₂ in the form of carbamino-hemoglobin in tissues.
Question 2:
Select the sequence of steps in Respiration:
- (A) Diffusion of gases (O₂ and CO₂) across the alveolar membrane.
- (B) Diffusion of O₂ and CO₂ between blood and tissues.
- (C) Transport of gases by the blood.
- (D) Pulmonary ventilation (inhalation of atmospheric air and exhalation of CO₂-rich air).
- (E) Utilization of O₂ by the cells for catabolic reactions and the resultant release of CO₂.
Choose the correct answer from the options given below:
- A. (D), (A), (C), (B), (E)
- B. (C), (B), (A), (E), (D)
- C. (B), (C), (E), (D), (A)
- D. (A), (C), (B), (E), (D)
Answer: A
Explanation: The correct sequence of respiration includes ventilation, gas diffusion across the alveolar membrane, gas transport, gas exchange between blood and tissues, and finally utilization of O₂ for cellular respiration.
Question 3:
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 altitudes, the body does not get sufficient oxygen.
Choose the correct answer from the options given below:
- A. (A) is true but (R) is false.
- B. (A) is false but (R) is true.
- C. Both (A) and (R) are true and (R) is the correct explanation of (A).
- D. Both (A) and (R) are true but (R) is not the correct explanation of (A).
Answer: C
Explanation: Both statements are true, and the reason correctly explains why altitude sickness occurs due to reduced oxygen availability in low-pressure environments.
Question 4:
Vital capacity of lung is:
- A. IRV + ERV + TV + RV
- B. IRV + ERV + TV – RV
- C. IRV + ERV + TV
- D. IRV + ERV
Answer: C
Explanation: Vital capacity is the total amount of air a person can expel after maximum inhalation, which includes Inspiratory Reserve Volume (IRV), Expiratory Reserve Volume (ERV), and Tidal Volume (TV).
Question 5:
Identify the region of the human brain which has the pneumotaxic center that alters respiratory rate by reducing the duration of inspiration:
- A. Cerebrum
- B. Medulla
- C. Pons
- D. Thalamus
Answer: C
Explanation: The pons houses the pneumotaxic center, which helps regulate the breathing rate by shortening the duration of inspiration.
Question 6:
Which of the following statements are correct with respect to vital capacity?
- A It includes ERV, TV, and IRV.
- B Total volume of air a person can inspire after a normal expiration.
- C The maximum volume of air a person can breathe in after forced expiration.
- D It includes ERV, RV, and IRV.
- E The maximum volume of air a person can breathe out after a forced inspiration.
Choose the most appropriate answer from the options given below:
- A. (a) and (e)
- B. (b), (d), and (e)
- C. (a), (c), and (d)
- D. (a), (c), and (e)
Answer: D
Explanation: Vital capacity includes ERV, TV, and IRV, and it is the maximum volume of air a person can breathe in or out after forced respiration.
Question 7:
Under normal physiological conditions in humans, every 100 ml of oxygenated blood can deliver __________ ml of O₂ to the tissues:
- A. 2 ml
- B. 5 ml
- C. 4 ml
- D. 10 ml
Answer: B
Explanation: Normally, about 5 ml of O₂ is delivered from every 100 ml of oxygenated blood to the tissues.
Question 8:
Which of the following is NOT a function of the conducting part of the respiratory system?
- A. It clears inhaled air from foreign particles.
- B. Inhaled air is humidified.
- C. Temperature of inhaled air is brought to body temperature.
- D. Provides surface for diffusion of O₂ and CO₂.
Answer: D
Explanation: The conducting part of the respiratory system does not facilitate gas exchange; this happens in the respiratory zone (alveoli).
Question 9:
Select the correct events that occur during inspiration:
(i) Contraction of diaphragm
(ii) Contraction of external intercostal muscles
(iii) Pulmonary volume decreases
(iv) Intra-pulmonary pressure increases
- A. Only (iv)
- B. (iii) and (iv)
- C. (i), (ii), and (iv)
- D. (i) and (ii)
Answer: D
Explanation: During inspiration, the diaphragm and external intercostal muscles contract, increasing pulmonary volume and reducing intra-pulmonary pressure.
Question 10:
Tidal Volume (TV) and Expiratory Reserve Volume (ERV) of an athlete are 500 mL and 1000 mL respectively. What will be his Expiratory Capacity (EC) if the Residual Volume (RV) is 1200 mL?
- A. 2200 mL
- B. 2700 mL
- C. 1500 mL
- D. 1700 mL
Answer: C
Explanation: Expiratory capacity (EC) is the sum of Tidal Volume (TV) and Expiratory Reserve Volume (ERV), which in this case is 500 mL + 1000 mL = 1500 mL.
