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.
Tissue Types. simple squamous epithelium. simple cuboidal epithelium. simple columnar epithelium. pseudostratified ciliated epithelium. one layer of flattened epithelial cells; diffuses, absorbs, anâ¦. one layer of cube-shaped epithelial cells; covers and lines glâ¦. one layer of rectangular-shaped epithelial cells; lines cavitiâ¦.