NEET Biology Breathing and Exchange of Gases Questions
Breathing and Exchange of Gases practice focused on ventilation, gas exchange, transport and respiratory regulation. Every preview below comes from NeetVellum's live original bank—not an unverified PYQ reconstruction.
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 1/5
The human trachea is held open by C-shaped cartilaginous rings that are incomplete dorsally. The most appropriate reason for this incomplete (C-shaped) arrangement is that it:
A. allows the ciliated epithelium to beat freely over the entire circumference
B. permits the trachea to collapse completely during forced expiration
C. keeps the airway patent while allowing the adjacent oesophagus to bulge during swallowing
D. enables the rings to secrete surfactant that lowers surface tension
Example 2 · difficulty 2/5
Alveolar air has a pO₂ of about 104 mm Hg, while the deoxygenated blood reaching the alveolar capillaries has a pO₂ of about 40 mm Hg. As a direct consequence of this gradient:
A. oxygen diffuses from the alveoli into the capillary blood until it equilibrates near 95 mm Hg
B. oxygen is pumped from the capillaries into the alveoli by active transport
C. carbon dioxide simultaneously diffuses from the alveoli into the blood
D. oxygen remains confined to the alveoli because the respiratory membrane is impermeable to gases
Example 3 · difficulty 2/5
Of the total carbon dioxide carried by human blood, the largest share is transported:
A. physically dissolved in the plasma
B. bound to the globin portion of haemoglobin as carbaminohaemoglobin
C. as stable carbonic acid circulating in the plasma
D. as bicarbonate ions, mostly delivered to plasma after forming inside RBCs
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.