AP BIOLOGY

Detailed explanation-1: -Cystic fibrosis is an example of a recessive disease. That means a person must have a mutation in both copies of the CFTR gene to have CF. If someone has a mutation in only one copy of the CFTR gene and the other copy is normal, he or she does not have CF and is a CF carrier.

Detailed explanation-2: -Examples of autosomal recessive disorders include cystic fibrosis, sickle cell anemia, and Tay-Sachs disease.

Detailed explanation-3: -Mutations in the CFTR gene cause cystic fibrosis. The CFTR gene provides instructions for making a channel that transports negatively charged particles called chloride ions into and out of cells. Chloride is a component of sodium chloride, a common salt found in sweat.

Detailed explanation-4: -Disease at a Glance Signs and symptoms may include salty-tasting skin; persistent coughing; frequent lung infections; wheezing or shortness of breath; poor growth; weight loss; greasy, bulky stools; difficulty with bowel movements; and in males, infertility.