NEET Biology Breathing and Exchange of Gases MCQs Set 12

Practice MCQs for NEET Biology Breathing and Exchange of Gases

Access targeted multiple-choice questions for Breathing and Exchange of Gases designed to align with the latest NEET academic syllabus for NEET Biology. These objective practice sets help students evaluate their conceptual understanding and improve exam readiness.

Access Breathing and Exchange of Gases Questions and Solutions

Navigate directly to the 50 objective questions for Breathing and Exchange of Gases using the digital viewer below. Each practice set includes verified answer keys, allowing students to instantly cross-check their work and identify areas requiring further revision.

Multiple Choice Questions

Question 1: Earthworms exchange gases through
(a) moist cuticle
(b) gills
(c) tracheal tubes
(d) lungs
Show Answer & Explanation

Answer: (a) moist cuticle

Explanation:
1. Earthworms respire through their moist cuticle, while insects use tracheal tubes.

Teacher's Note:
1. Aquatic arthropods and molluscs have gills.

Question 2: Insects respire through
(a) gills
(b) tracheal tubes
(c) lungs
(d) skin
Show Answer & Explanation

Answer: (b) tracheal tubes

Explanation:
1. A network of tracheal tubes carries air directly to tissues in insects.

Teacher's Note:
1. Reptiles, birds and mammals use vascularised lungs.

Question 3: The opening of the larynx into the pharynx is called the
(a) epiglottis
(b) glottis
(c) trachea
(d) uvula
Show Answer & Explanation

Answer: (b) glottis

Explanation:
1. The glottis is the opening of the larynx that is covered by the epiglottis during swallowing.

Teacher's Note:
1. The larynx is the sound box.

Question 4: Trachea divides into right and left primary bronchi at the level of the
(a) first cervical vertebra
(b) twelfth thoracic vertebra
(c) third lumbar vertebra
(d) fifth thoracic vertebra
Show Answer & Explanation

Answer: (d) fifth thoracic vertebra

Explanation:
1. The trachea divides at about the T5 level.

Teacher's Note:
1. The tracheal rings are incomplete.

Question 5: The conducting part of the respiratory system extends from the external nostrils up to the
(a) terminal bronchioles
(b) alveoli
(c) alveolar ducts
(d) respiratory bronchioles
Show Answer & Explanation

Answer: (a) terminal bronchioles

Explanation:
1. The conducting part carries air and warms and humidifies it, while the exchange part has alveoli and their ducts.

Teacher's Note:
1. Gas exchange occurs in the exchange part.

Question 6: The tidal volume in a healthy human is about
(a) 1100 mL
(b) 1200 mL
(c) 500 mL
(d) 3000 mL
Show Answer & Explanation

Answer: (c) 500 mL

Explanation:
1. Tidal volume is the air inspired or expired in a normal breath, around 500 mL.

Teacher's Note:
1. Minute ventilation is tidal volume times rate.

Question 7: The volume of air remaining in the lungs after a forced expiration is the
(a) expiratory reserve volume
(b) tidal volume
(c) residual volume
(d) vital capacity
Show Answer & Explanation

Answer: (c) residual volume

Explanation:
1. Residual volume is about 1200 mL.

Teacher's Note:
1. Functional residual capacity equals ERV plus RV.

Question 8: Vital capacity is about 4200 mL in humans. It is the sum of
(a) ERV and RV
(b) tidal volume and RV
(c) IRV and RV
(d) ERV, tidal volume and IRV
Show Answer & Explanation

Answer: (d) ERV, tidal volume and IRV

Explanation:
1. Vital capacity is the maximum air expired after a forced inspiration: ERV + TV + IRV.

Teacher's Note:
1. Total lung capacity includes residual volume as well.

Question 9: Inspiratory capacity of about 3000 mL is the sum of
(a) tidal volume and expiratory reserve volume
(b) ERV and RV
(c) tidal volume and inspiratory reserve volume
(d) IRV and ERV
Show Answer & Explanation

Answer: (c) tidal volume and inspiratory reserve volume

Explanation:
1. Inspiratory capacity = TV + IRV.

Teacher's Note:
1. FRC = ERV + RV is about 2300 mL.

Question 10: Which of the following does NOT affect the rate of diffusion of gases across the respiratory membrane?
(a) Colour of the blood
(b) Pressure or concentration gradient
(c) Solubility of gases
(d) Thickness of the membrane
Show Answer & Explanation

Answer: (a) Colour of the blood

Explanation:
1. Diffusion depends on partial pressure gradient, solubility and membrane thickness.

Teacher's Note:
1. CO2 is about 20 to 25 times more soluble than O2.

Question 11: The diffusion membrane of alveoli is made of
(a) thick columnar epithelium of alveoli only
(b) thin squamous epithelium of alveoli, endothelium of capillaries and basement substance between them
(c) cartilage and muscle
(d) ciliated epithelium of the bronchus
Show Answer & Explanation

Answer: (b) thin squamous epithelium of alveoli, endothelium of capillaries and basement substance between them

Explanation:
1. The three layers together are less than a millimetre thick, favouring rapid diffusion.

Teacher's Note:
1. Columnar epithelium would be too thick.

Question 12: The oxygen dissociation curve of haemoglobin is
(a) hyperbolic
(b) linear
(c) parabolic
(d) sigmoid
Show Answer & Explanation

Answer: (d) sigmoid

Explanation:
1. The curve is S-shaped because of cooperative binding of oxygen.

Teacher's Note:
1. It shifts right with high pCO2, high H+ and high temperature.

Question 13: Which factor favours the formation of oxyhaemoglobin in alveoli?
(a) Low pO2 and high pCO2
(b) High H+ and high temperature
(c) High pCO2 only
(d) High pO2, low pCO2 and lesser H+ concentration
Show Answer & Explanation

Answer: (d) High pO2, low pCO2 and lesser H+ concentration

Explanation:
1. In alveoli, high pO2, low pCO2, lower H+ and lower temperature favour oxygen binding.

Teacher's Note:
1. The opposite happens in tissues.

Question 14: Every 100 mL of oxygenated blood delivers about ______ mL of O2 to the tissues.
(a) 20
(b) 5
(c) 15
(d) 40
Show Answer & Explanation

Answer: (b) 5

Explanation:
1. Under normal conditions oxygenated blood can deliver about 5 mL of O2 per 100 mL to tissues.

Teacher's Note:
1. Deoxygenated blood delivers about 4 mL of CO2 per 100 mL to alveoli.

Question 15: The largest part of CO2 is transported as
(a) dissolved in plasma
(b) carbamino-haemoglobin
(c) bicarbonate
(d) carbon monoxide
Show Answer & Explanation

Answer: (c) bicarbonate

Explanation:
1. About 70 percent of CO2 is carried as bicarbonate, 20 to 25 percent as carbamino-haemoglobin and 7 percent dissolved.

Teacher's Note:
1. Carbonic anhydrase speeds up bicarbonate formation in RBCs.

Question 16: Dissociation of CO2 from carbamino-haemoglobin occurs when
(a) pCO2 is high and pO2 is low
(b) both are high
(c) pCO2 is low and pO2 is high
(d) both are low
Show Answer & Explanation

Answer: (c) pCO2 is low and pO2 is high

Explanation:
1. In the alveoli, low pCO2 and high pO2 release CO2 from carbamino-haemoglobin.

Teacher's Note:
1. The reverse happens at tissues.

Question 17: The respiratory rhythm centre is located in the
(a) pons
(b) cerebellum
(c) medulla oblongata
(d) hypothalamus
Show Answer & Explanation

Answer: (c) medulla oblongata

Explanation:
1. The rhythm centre in the medulla is moderated by the pneumotaxic centre in the pons.

Teacher's Note:
1. A chemosensitive area near it is highly sensitive to CO2 and H+.

Question 18: The pneumotaxic centre that moderates the respiratory rhythm centre is in the
(a) medulla
(b) cerebrum
(c) spinal cord
(d) pons
Show Answer & Explanation

Answer: (d) pons

Explanation:
1. The pneumotaxic centre in the pons can reduce the duration of inspiration.

Teacher's Note:
1. This changes the respiratory rate.

Question 19: Asthma is characterised by
(a) damage of alveolar walls
(b) fibrosis due to dust
(c) wheezing due to inflammation of bronchi and bronchioles
(d) collapse of pleura
Show Answer & Explanation

Answer: (c) wheezing due to inflammation of bronchi and bronchioles

Explanation:
1. Asthma causes difficulty in breathing with wheezing.

Teacher's Note:
1. Emphysema is alveolar wall damage and the cause is mainly cigarette smoking.

Free study material for Biology

Multiple Choice Questions (MCQs) for NEET Biology Breathing and Exchange of Gases

About Breathing and Exchange of Gases MCQs for NEET Biology

Review structured objective questions for NEET Biology Breathing and Exchange of Gases. Built according to official NEET guidelines, these MCQ sets support daily revision and core concept reinforcement.

How to Verify Your MCQ Answers

Built using the official NCERT book for NEET, these Biology objective sets provide reliable academic guidance. Pair your practice with our recommended NCERT solutions to master optimal problem-solving approaches.

Enhance Speed with Online MCQ Tests

Explore our broader library of printable assignments, chapter notes, and mock tests designed to support continuous revision and secure higher marks in NEET assessments.

FAQs

Where can I access latest NEET Biology Breathing and Exchange of Gases MCQs Set 12?

You can get most exhaustive NEET Biology Breathing and Exchange of Gases MCQs Set 12 for free on StudiesToday.com. These MCQs for NEET Biology are updated for the 2026-27 academic session as per NEET examination standards.

Are Assertion-Reasoning and Case-Study MCQs included in the Biology NEET material?

Yes, our NEET Biology Breathing and Exchange of Gases MCQs Set 12 include the latest type of questions, such as Assertion-Reasoning and Case-based MCQs. 50% of the NEET paper is now competency-based.

How do practicing Biology MCQs help in scoring full marks in NEET exams?

By solving our NEET Biology Breathing and Exchange of Gases MCQs Set 12, NEET students can improve their accuracy and speed which is important as objective questions provide a chance to secure 100% marks in the Biology.

Do you provide answers and explanations for NEET Biology Breathing and Exchange of Gases MCQs Set 12?

Yes, Biology MCQs for NEET have answer key and brief explanations to help students understand logic behind the correct option as its important for 2026 competency-focused NEET exams.

Can I practice these Biology NEET MCQs online?

Yes, you can also access online interactive tests for NEET Biology Breathing and Exchange of Gases MCQs Set 12 on StudiesToday.com as they provide instant answers and score to help you track your progress in Biology.