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.
Pseudostratified epithelium is a type of epithelial tissue that at first glance appears to be stratified, but is actually only a single layer of cells.seudostratified columnar epithelium is located in the trachea, upper respiratory tract, and in the male reproductive system, particularly in the vas deferens and epididymis. Pseudostratified epithelial tissue typically, but not always, has goblet cells, which secrete mucin to produce mucus.