Cystic fibrosis is an inherited respiratory disorder in which the mucociliary escalator no longer functions because of the presence of excessively dense and viscous mucus. Which of the following components of the respiratory system are affected by cystic fibrosis?

A. oblet cells

B. cilia

C. lungs

D. All of the listed responses are correct.

C. lungs

Explanation:

Cystic fibrosis is a genetic disease caused by the mutation in the CF gene located on chromosome 7 which codes for the CFTR protein.

Cystic fibrosis transmembrane regulator protein or CFTR encoded protein regulates the movement of the water and chloride and sodium ions in and out of the cell.

The mutated gene forms abnormal protein which disrupts the movement of the ions and water in and out of the cell.

As a result of thick, the person develops thick and sticky mucus in the respiratory organs, especially in the lungs. Other organs of the body are also affected.

Thus, the lungs are the correct answer.