A dominant gene will always be expressed when present, such as in the homozygous dominant genotype (RR), or heterozygous genotype (Rr). A recessive allele is only expressed wh â¦ en the genotype is homozygous recessive (rr).
(Lung alveoli, in contrast, are lined by very thin simple squamous epithelium .). Pseudostratified respiratory epithelium consists primarily of columnar ciliated cells. Ciliary beating sweeps mucus and the dust it carries up the bronchi and trachea toward the pharynx, where it can be swallowed.
Can be found in the lining of the trachea, most of the upper respiratory tract. There role is to keep mucus and any other debris from entering the lower reaches of the lung tissue by moving in a upward direction. 19. Transitional epithelium is actually stratified squamous epithelium with special characteristics.imple means that there is only one layer of these cells, not as much protection as stratified which indicates several layers of cells. Stratified epithelia are named according to the cells at the apical surface of the epithelial membrane, not those resting on a basement membrane like the simple epithelia.