Emphysema disease is caused by

Ravi,who lived at sea level,had around $5$ million $RBC$ per cubic millimeter of his blood. Later when he lived at an altitude of $18,000 \ ft$,he showed around $8$ million $RBC$ per cubic millimeter of blood. This is an adaptation because

Select the correct match of disease and its symptom.

In which of the following disorders do the alveoli get filled with fluid, leading to severe problems in respiration?

Due to increasing air-borne allergens and pollutants,many people in urban areas are suffering from respiratory disorders causing wheezing due to:

''Emphysema'' is a condition in which.....