Breathing and Exchange of Gases NEET PYQ Analysis — 22 Questions Decoded (2015-2026)

A small Class 11 chapter that NTA mines for clean, NCERT-faithful marks.

Breathing and Exchange of Gases is a compact chapter, and that is exactly why it pays off. The content is finite, the facts are precise, and the questions almost never stray from the textbook. Across the PYQ record, Breathing and Exchange of Gases has delivered 22 NEET questions (2015-2026), with a weightage trend that is Stable.

NTA returns to this chapter because it is full of exact numbers and tidy classifications — lung volumes and capacities in millilitres, the partial pressures of oxygen and carbon dioxide, the percentage of carbon dioxide carried as bicarbonate. These hard facts feed directly into match-the-column and sequencing questions. NEET 2026 proved it with 3 questions, all NCERT-direct.

This analysis breaks down what NTA actually asks, the exact NCERT facts behind the questions, the three questions from NEET 2026, and how to prepare this chapter for NEET 2027.

Section 1 — What Breathing and Exchange of Gases Covers in NCERT

Breathing and Exchange of Gases is an NCERT Class 11 chapter in the Human Physiology unit (Zoology division). It covers respiratory organs across animal groups, the human respiratory system, the mechanism of breathing (inspiration and expiration via the diaphragm and intercostal muscles), respiratory volumes and capacities, exchange of gases at the alveoli and tissues, transport of oxygen and carbon dioxide, the regulation of respiration, and respiratory disorders such as asthma, emphysema and occupational lung diseases.

It pairs naturally with Body Fluids and Circulation, since gas transport depends on blood. Total PYQ count: 22 (2015-2026). Class: 11.

Section 2 — Weightage and Trend

No source dataset carries a reliable year-by-year split for this chapter, so rather than invent one, here is the official weightage profile from MedicNEET's chapter-weightage model:

The signal is clear: Breathing and Exchange of Gases is a stable, low-volume chapter that averages around 1-2 questions a paper. NEET 2026's three-question showing was a slight high — do not bank on that every year, but do not skip the chapter either. Cross-check it against the full NEET Biology chapter weightage analysis. Expect 1-2 questions in NEET 2027.

Section 3 — Topic-wise Breakdown

Across the PYQ set, NTA returns to a tight cluster of topics. The highest-yield areas:

• Respiratory volumes and capacities — tidal volume, IRV, ERV, residual volume, vital capacity, total lung capacity, with their NCERT millilitre ranges. This is the single most-tested topic.
• Transport of gases — oxyhaemoglobin, the oxygen dissociation curve, and carbon dioxide carried as bicarbonate (about 70%), as carbamino-haemoglobin (about 20-25%), and dissolved (about 7%).
• Mechanism of breathing — the roles of the diaphragm, external and internal intercostal muscles, and intrapulmonary pressure.
• Exchange of gases — partial pressure gradients and the steps of respiration.

Repeating NCERT concepts: the partial pressures of oxygen and carbon dioxide in alveoli, blood and tissues, and the role of the respiratory rhythm centre in the medulla.

Rarely or never asked — safe to deprioritise: exhaustive detail on the histology of the conducting passages. Know the broad structure, not every minor cell type. Practise the full set on the Breathing and Exchange of Gases PYQ page.

Section 4 — Question Format Analysis

Pre-2026: questions were mostly direct single-fact recall — "What is the value of tidal volume?", "Most carbon dioxide is transported as?"

NEET 2026: the format leaned hard into matching and sequencing. Of the three questions, one asked you to order the five steps of respiration, and two were match-the-column — one on respiratory volumes and one on respiration types across organisms. All three demanded that you hold a cluster of facts at once.

Going forward: expect this chapter to stay matching-heavy. Memorising one number is not enough — you must know the full set of volumes and the full set of respiration types together. If matching and sequencing formats are your weak spot, read Match-the-Column Questions: The Format That Destroys NEET Scores.

Section 5 — NEET 2026 Decoded

Here are the exact three Breathing and Exchange of Gases questions from the NEET 2026 paper, decoded:

1. Order the steps of respiration (sequencing) — The correct order is C, B, E, A, D: pulmonary ventilation, then diffusion across the alveolar membrane, then transport of gases by blood, then diffusion between blood and tissues, and finally cellular respiration. The trap: starting with cellular respiration or with tissue-level diffusion. NCERT concept — respiration begins with breathing in atmospheric air and ends with the utilisation of oxygen by cells.
2. Match respiratory volumes with values (match-the-column) — The correct pairing is ERV–1000-1100 mL, RV–1100-1200 mL, IRV–2500-3000 mL, TV–500 mL. The traps come from swapping ERV and RV, whose ranges are close. NCERT concept — tidal volume is about 500 mL, IRV is 2500-3000 mL, ERV is 1000-1100 mL and residual volume is 1100-1200 mL.
3. Match organisms with respiration type (match-the-column) — The correct pairing is Molluscs–branchial respiration, Reptiles–pulmonary respiration only, Adult amphibians–pulmonary and cutaneous respiration, Amoeba–cellular respiration (by diffusion across the body surface). The trap: assigning amphibians lungs only and forgetting their cutaneous (skin) component. NCERT concept — different animal groups use different respiratory organs, but the gas exchange itself always occurs by simple diffusion.

Every one of these maps to a plain NCERT line — not a single question came from outside the textbook.

Section 6 — Strategy for This Chapter

• Time to allot: 1-2 focused days. It is small and high-ROI for the effort.
• NCERT sections to nail: the complete table of respiratory volumes and capacities, the three modes of carbon dioxide transport with their percentages, the breathing mechanism, and the respiration types across animal groups.
• Common mistakes: (1) swapping ERV and residual volume values; (2) confusing vital capacity with total lung capacity; (3) forgetting amphibians use cutaneous respiration too; (4) reversing the order of the respiration steps.
• How to approach it for RENEET / NEET 2027: learn the volumes as a single block, not as isolated numbers, and practise the step-ordering question until it is automatic. Drill the chapter on the Breathing and Exchange of Gases PYQ set and under timed conditions with the RENEET test series.

Section 7 — Most Repeated Concepts

The five concepts that recur most across Breathing and Exchange of Gases PYQs, with the NCERT lines to memorise word-for-word:

1. Tidal volume is the volume of air inspired or expired during a normal respiration — about 500 mL per breath.
2. Vital capacity is the maximum volume of air a person can breathe in after a forced expiration, or breathe out after a forced inspiration — it includes ERV, TV and IRV.
3. "Nearly 70 per cent of carbon dioxide is transported as bicarbonate, about 20-25 per cent as carbamino-haemoglobin, and about 7 per cent in a dissolved state in plasma."
4. "The exchange of gases occurs in the alveoli and at the tissues by simple diffusion, mainly based on pressure or concentration gradient."
5. The respiratory rhythm centre, located in the medulla, regulates respiration, and a pneumotaxic centre in the pons can moderate its activity.

Breathing and Exchange of Gases is a winnable chapter — small, NCERT-faithful, and predictable. Learn the volumes as a block, the transport percentages by heart, and the step order cold, and it converts into reliable marks. Start with the free Breathing and Exchange of Gases PYQ set and build your full plan around the chapter weightage data.