Replacement of columnar epithelium in respiratory tract to squamous epithelium is ?
Ans. is `c' i.e., Metaplasia Metaplasia Metaplasia is a reversible change in which one differentiated cell type is replaced by another differentiated cell type. Metaplasia represents an adaptive substitution of cells that are sensitive to stress by cell types better able to withstand the adverse environment.
Hyperplasia
Hypoplasia
Metaplasia
None of the above