Which statement is true? Bronchitis can result in hoarseness. Cystic fibrosis is a genetic disorder that causes thick mucus secretions. Asthma causes a loss of appetite and weight. Pneumonia is an inflammation of the lungs that is caused only by bacteria.

Answer: Cystic fibrosis is a genetic disorder that causes thick mucus secretions.

Explanation:

Cystic fibrosis is a genetic disorder caused by mutations in a gene that makes a protein called CFTR (cystic fibrosis transmembrane regulator). The CFTR protein normally functions as a channel for transport of chloride ions in cells responsible for mucus production. A person suffering from cystic fibrosis produces abnormal CFTR protein or no CFTR protein at all. This is the reason that thick, sticky mucus is produced instead of the thin, watery kind.

Cystic fibrosis is a genetic disorder that causes thick mucus secretions.