Cystic fibrosis is characterized by which of the following?

Cystic fibrosis is primarily characterized by the production of thick and sticky mucus, which can obstruct the airways and lead to breathing difficulties. The condition is caused by mutations in the CFTR gene, which is responsible for regulating the movement of salt in and out of cells. This malfunction results in the production of mucus that is not only thick but also difficult to clear from the lungs and digestive system. The accumulation of this mucus creates an environment conducive to bacterial infections and may affect the pancreas' ability to secrete digestive enzymes, leading to further complications for individuals with the disease. Understanding this characteristic is crucial for diagnosis and management of cystic fibrosis, as treatments often aim to improve mucus clearance and respiratory health.

In contrast, the other options—joint dislocation, muscle degeneration, and neuropathy—are not related to cystic fibrosis and pertain to different medical conditions that involve the musculoskeletal and nervous systems.