Cilia are small micro-structural hairs that are attached on the bronchus of the lungs as projections. These projections have goblet cells which secrete mucus and help in trapping impurities in it thereby allowing microbes and dust free air into the lungs. It protects the lungs from all sort of invasion. Cilia's are composed of proteins and only in case of lung lining are non-moving structures.
If any part of the DNA is changed, such as the base pairs, then it would result in the mutation of the DNA, causing it to carry out a different function
