Question

Animal cell is limited by:
(A)Plasma Membrane
(B)Mitochondria
(C)Cell wall
(D)Basement Membrane

Answer 1

Hint:It is a semi-permeable membrane and also plays an important role in endocytosis and exocytosis.It is selectively permeable.

Complete answer
The plasma membrane envelops all cells and physically divides the cytoplasm outside the cell from the extracellular fluid. This protects all of the cell's elements from the outside environment and allows for distinct operations within and outside the cell. It controls the materials coming in and going out of the cell.
Mitochondria are cell organelles involved in the synthesis of ATP. Cell wall is present in plant cells that provide plants with structural support. The basement membrane is a thin specialised extracellular matrix found between the epidermis and the dermis.

Additional Information:
Functions of the Plasma Membrane:
1. The cell is protected structurally by the plasma membrane. It binds the cytoskeleton, which is a system of protein filaments in the cell that hold all cell parts in position.
2. Another significant plasma membrane function is to facilitate contact and signaling between cells. It does so by the use of different membrane proteins and carbohydrates.
Plasma Membrane Structure:
1. The membrane consists mainly of the molecules called phospholipids, which naturally assemble into a double layer.
2. Proteins are coated between the lipids that constitute the membrane and these transmembrane proteins enable molecules that would otherwise not be able to reach the cell, to pass through by forming channels, pores or gates.
3. Carbohydrates are also present in the plasma membrane; in fact, most carbohydrates are part of glycoproteins.

So, the correct answer is Plasma Membrane.

Note:The plasma membrane may easily disperse lipids, proteins and carbohydrates across the cell membrane; they basically float throughout its surface. This is known as the fluid mosaic model, coined by S.J. Singer and G.L Nicolson.