Question

primary ciliary dyskinesia (pcd) is a rare genetic disease. affected individuals exhibit impaired functioning of ciliated cells. based on what you know about the role of cilia in eukaryotic cells, why should you expect people with pcd to be particularly susceptible to respiratory infections? view available hint(s)

• people with pcd are resistant to many antibiotics.
• people with pcd are unable to cough.
• cilia are responsible for clearing bacteria and mucus from the lungs of your airways.
• people with pcd have a mutation in a gene that codes for a plasma membrane protein (cftr) that is the target for a toxin produced by the cholera bacterium.

Explanation:

To determine why people with Primary Ciliary Dyskinesia (PCD) are susceptible to respiratory infections, we analyze the role of cilia in mucous cells. Cilia in the respiratory tract are responsible for moving (trapping and expelling) bacteria and mucus out of the airways. In PCD, cilia function is impaired.

• Option 1: Resistance to antibiotics is not related to cilia function in PCD, so this is incorrect.
• Option 2: The inability to cough is not the primary reason; cilia's role in moving pathogens/mucus is key, so this is incorrect.
• Option 3: Since cilia are responsible for clearing bacteria and mucus from the airways, impaired cilia (as in PCD) would mean this clearing doesn't happen, leading to more infections. This matches the role of cilia.
• Option 4: The mutation related to a plasma membrane protein and cholera toxin is not related to respiratory infections via cilia function in PCD, so this is incorrect.

Answer:

C. Cilia are responsible for clearing bacteria and mucus from the airways of your lungs