Q4. Assertion: the conducting part of the respiratory system does not exchange gases. Reason: it only transports, cleans and humidifies the air and brings it to body temperature. Are both true, and does the reason explain the assertion?
Both statements fit NCERT’s conducting/exchange distinction (page 185), but listing transport functions alone is not the structural explanation. The conducting airways lack the thin alveolar surface; modern anatomy includes respiratory bronchioles in the exchange region.
Q5. Which parts of the airway are supported by incomplete cartilaginous rings?
NCERT page 184 lists the trachea, primary, secondary and tertiary bronchi, and initial bronchioles. Modern histology corrects the last item: bronchioles lack cartilage, and intrapulmonary bronchi have cartilage plates rather than tracheal-style rings (StatPearls, “Histology, Lung”).
Q6. What are branchial, pulmonary and cutaneous respiration?
Branchial: respiration by gills; pulmonary: by lungs; cutaneous: through the moist skin, as in frogs (NCERT page 183).
Q7. On what two factors does the mechanism of breathing in an animal group mainly depend?
Its habitat and its level of organisation (NCERT page 183).