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Biology

Breathing and Exchange of Gases

A Biology chapter of the NEET syllabus, and how to practise it for the computer-based exam.

Exam rules change between cycles. Confirm dates, syllabus and pattern against NTA's official site. We are not NTA.

Weightage: what the paper actually did

Breathing and Exchange of Gases carried 3 questions in the NEET 2026 paper. One paper is a data point, not a destiny: NTA moves weight between chapters every cycle, which is why the weightage tables deserve care. The stable facts are the paper's shape: 180 questions, 720 marks, +4 right, −1 wrong.

Sample PYQs from this chapter

Real questions NTA asked from Breathing and Exchange of Gases, with the answer and the working. Try before you peek.

Question 1 · NEET 2026

Sponges exchange O2\mathrm{O}_{2} with CO2\mathrm{CO}_{2} by __________.
  1. A.simple diffusion over their entire body surfaces
  2. B.moist cuticle
  3. C.tracheal tubes
  4. D.gills
Answer and explanation

Answer: A

Lower invertebrates such as sponges, coelenterates and flatworms have no specialised respiratory organs at all. Their bodies are thin enough and their cells close enough to the surrounding water that simple DIFFUSION across the whole body surface suffices for gas exchange. NCERT Class 11, Breathing and Exchange of Gases.

Question 2 · NEET 2020

Identify the wrong statement with reference to transport of oxygen.
  1. A.Partial pressure of CO2\mathrm{CO}_{2} can interfere with O2\mathrm{O}_{2} binding with haemoglobin
  2. B.Higher H+ conc. in alveoli favours the formation of oxyhaemoglobin
  3. C.Low pCO2 in alveoli favours the formation of oxyhaemoglobin
  4. D.Binding of oxygen with haemoglobin is mainly related to partial pressure of O2\mathrm{O}_{2}
Answer and explanation

Answer: B

Higher H+\mathrm{H}^{+} concentration in the alveoli does not favour the formation of oxyhaemoglobin; instead, it promotes the release of O2\mathrm{O}_{2} from haemoglobin. Chapter: Breathing and Exchange of Gases.

How to practise Breathing and Exchange of Gases

Chapter by chapter, against real past-paper questions, on a screen: NEET is computer based from 2027. Read the chapter once, then attempt its PYQs until your accuracy stops climbing, and let the wrong answers tell you which lines to reread. If the chapter keeps refusing to stick, that has its own guide. There is also a free NEET mini mock with answers.

Nearby Biology chapters

Questions

How many questions did Breathing and Exchange of Gases have in NEET 2026?

Breathing and Exchange of Gases carried 3 questions in the NEET 2026 paper. Weightage shifts between cycles, so treat it as a probability, not a promise.

Where can I practise Breathing and Exchange of Gases PYQs for NEET?

Explore available chapter-wise NEET practice in BrainIt, free until the 2027 exam. Review explanations and track chapter accuracy to guide your revision. Sample questions from this chapter are on this page.

Is Breathing and Exchange of Gases important for NEET 2027?

It is part of the Biology syllabus the paper draws from, and NEET 2027 is computer based, so practise it on a screen. Your own accuracy in the chapter matters more than any weightage table: a heavy chapter you already score well on needs less time than a light one you keep missing.

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