2018 source guide · Biology

NEET 2018 Biology Breathing and Exchange of Gases Questions

Use this page to connect the official 2018 paper with current Biology practice. NeetVellum does not claim a chapter appeared in that paper until the official question and final key have been mapped.

Practice 100 verified questions →Check official NTA archive ↗

What to master

ventilation, gas exchange, transport and respiratory regulation.

Original practice preview

These are current-syllabus NeetVellum questions, shown separately from historical-paper provenance.

Example 1 · difficulty 4/5

During transport, CO₂ is largely trapped as bicarbonate at the tissue level. Which sequence correctly describes what happens to this bicarbonate once the blood reaches the alveoli?

A. HCO₃⁻ keeps accumulating inside RBCs while chloride ions leave them
B. carbonic anhydrase converts more CO₂ into H₂CO₃, further acidifying the RBCs
C. HCO₃⁻ re-enters RBCs, combines with H⁺ to form H₂CO₃, which splits into CO₂ and H₂O, and the CO₂ diffuses into alveolar air
D. HCO₃⁻ binds directly to the globin chains of haemoglobin and is exhaled as carbaminohaemoglobin breaks down

Example 2 · difficulty 4/5

A chronic smoker shows permanent enlargement of air spaces due to destruction of alveolar walls, while a stone-crushing industry worker develops progressive fibrosis of lung tissue. The two diagnoses, respectively, are:

A. asthma and asbestosis
B. emphysema and silicosis
C. emphysema and asthma
D. silicosis and emphysema

Example 3 · difficulty 1/5

Which respiratory surface is correctly matched with Earthworm?

A. moist cuticle
B. gills
C. tracheal tubes
D. book lungs

The evidence-first practice loop

1. Verify provenanceOfficial paper and final key before accepting a PYQ label.
2. Attempt closed-bookExpose the concept or execution gap before rereading.
3. Repair and returnClassify the miss and re-practice after a delay.

Canonical chapter practice

Breathing and Exchange of Gases →

Frequently asked questions

Are these official NEET 2018 Biology Breathing and Exchange of Gases PYQs?

No. The previews are original NeetVellum practice questions. A historical item receives a PYQ label only after its official paper and authoritative final answer key are attached. Use the official archive for the source paper.

How should I use the NEET 2018 paper?

Solve the official paper under its original timing, verify against the final key, classify every miss, and then use the linked current-syllabus practice bank to repair the exposed concept.