Question

Which one of the following components of plasma membrane is involved in the enlargement of cell surface area?
A) Cilia
B) Microvilli
C) Desmosomes
D) Gap junctions

Answer 1

Plasma membrane is also called the cell membrane. It is the membrane found in all the cells. It separates the interior of the cell from the external environment of the cell. Plasma membrane is semi-permeable membrane which means that it allows the movement of selective molecules or ions across itself.

Complete answer :

Cilia:-Cilia are short hair like structures.They are used to move the entire cell or help in the movement of substances along the outer surface of the cell.Cilia are present in many numbers.They extend along the entire surface of the plasma membrane.
Microvilli:-Microvilli are the microscopic protrusion of the plasma membrane.Microvilli increase the surface area of the cell for diffusion and minimize any increase in volume of the cell.They are involved in absorption, secretion, cellular adhesion and mechanotransduction.Microvilli because of its vital function is packed with enzymes that help in the breakdown of the complex nutrients into the simpler compounds so that they can be easily absorbed.So the microvilli also increases the number of digestive enzymes that are present on the surface of the cell.
Desmosome:-A desmosome is a cell structure which is specialized for cell to cell adhesion.Desmosomes are one of the stronger cell-to-cell adhesion type.Desmosomes maintain the mechanical integrity of the tissue.They are found in tissues which experience more mechanical stress such as cardiac muscle tissue, bladder tissue, etc.The term desmosome was coined by Josef Schaffer in 1920.Desmosomes are also called as the adherens junctions (AJs).
Gap Junctions:-Gap junctions are the specialized intercellular connections between the animal cells.They directly connect the cytoplasm of two cells.Gap junctions allow various molecules, ions and electrical impulses to directly pass through a regulated gate between cells.Gap junction is also called nexus or macula communicans.They are analogous to plasmodesmata that are present in the plant cells.
Therefore, it has been clear from the above discussion that Microvilli components of the plasma membrane are involved in the enlargement of cell surface area.

Hence, option B is the correct answer.

Note: Plasma membrane is also called as the cell membrane. It is the membrane found in all the cells. It separates the interior of the cell from the external environment of the cell. Plasma membrane is semi-permeable membrane which means that it allows the movement of selective molecules or ions across itself.