"Long exposure of certain substances can give rise to inflammation leading to fibrosis". This condition is present in $ - $

Smoking increases . . . . . . content in blood and reduces the concentration of haem-bound oxygen. Fill in the blank suitably.

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

Which one of the following is $NOT$ a psychological disorder?

Excessive smoking leads to an increase in the concentration of which substance in the blood?

Name the chronic respiratory disorder caused mainly by cigarette smoking.