Examination of a tissue sample reveals groups of cells united by junctional complexes and interlocking membranes. The cells have one free surface and lack blood vessels. The tissue is most likely tissue. a. muscle b. connective c. neural d. adipose e. epithelial

The correct answer is: e. epithelial.

Explanation:

The structure of epithelial cell membrane is not uniform.They usually form the lining of a cavity, lumen or a tissue.It comprises of two parts: An apical part from where the membrane extends out to form finger like projections. This part usually faces the lumen and is responsible for secretion or absorption.Opposite to the apical part is located the basolateral part where the membrane is smooth without the formation of finger-like projections. This part remain in contact with the basement membrane beneath which the blood vessels are located.Molecules or substances undergo directional movement from the apical to the basoleteral region of the epithelial cell or vice versa depending upon whether it is acting as the secretory cell or absorptive cell.The rest of the two sides of the cell remains tightly attached to the adjacent cells by means of tight junctions, adherent junctions and desmosomes.This is necessary to prevent molecules from bypassing the usual directional motion through the cells.Most of the membrane proteins and carrier proteins are located on the apical and basolateral membrane of the cell.