Question

Assertion: The atmospheric air that reaches the alveoli is clear and humidified.
Reason: Respiratory tree is responsible for clearing out foreign particles and humidifying the atmospheric air.

• A. Both the assertion and reason are true and the reason is the correct explanation for the assertion
• B. Both the assertion and reason are true but the reason is not the correct explanation for the assertion
• C. Assertion is true but the reason is false
• D. Reason is true but the assertion is false

Answer 1

The correct option is C Assertion is true but the reason is false

There are two zones in the human respiratory system - the conducting zone and the exchange zone. The conducting zone starts with the external nostrils in the nose and ends with the terminal bronchioles of the bronchial tree in the lungs. The terminal bronchioles form the respiratory bronchioles which is a part of the exchange zone. The exchange zone ends with the alveoli. The conducting zone is responsible for the transportation of atmospheric air into the exchange zone, filtering the air from foreign particles along with humidifying it and bringing it to body temperature. As a result, the alveoli get clear and humidified air. The exchange zone is also called the respiratory tree which is the site of gaseous exchange between blood and atmospheric air.