Question 16

The apical side of an epithelial cell is on the top side of the cell.

The apical side of an epithelial cell is indeed located on the top side of the cell, facing either the external environment or the lumen of an organ.

A) Is exposed to fluid or air

This statement describes the function of the apical side, but it does not specifically answer the question regarding its location. While the apical side may be exposed to fluid or air, this option does not explicitly indicate that it is on the top side of the cell.

B) Is on the top side of the cell

This option accurately identifies the location of the apical side of an epithelial cell. The apical surface is characterized as the uppermost layer of the epithelial tissue, making this the correct answer.

C) Does not allow any substances to pass through

This statement is incorrect as it misrepresents the nature of the apical side. The apical surface can have various permeability properties depending on the type of epithelial tissue, and it often allows substances to pass through, especially in epithelial tissues involved in absorption and secretion.

D) None of the above

This option is incorrect as it negates all previous statements. Since option B correctly identifies the location of the apical side, this option cannot be correct.

Conclusion

In summary, option B is definitively correct as it directly answers the question regarding the location of the apical side of an epithelial cell. The other options either provide incorrect information or do not accurately address the question, thus reinforcing the correctness of option B.