Question

The endoskeleton of cell is made up of
A. Cell wall
B. Endoplasmic reticulum
C. Cytoplasm
D. Mitochondria

Answer 1

Hint: The endoskeleton refers to the internal membrane system of the cell. It forms the basic internal structure of the cells and acts as a it’s supporting layer. As the bones provide shape, support and protection to the body in the same way the endoskeleton provides shape, support and protection to the cell.

Complete answer: The endoplasmic reticulum forms the cytoskeleton of the cell which is also referred to as the endoskeleton of the cell. It acts as a cytoplasmic framework which provides the area for the crucial biological and biochemical activities of the cell.
The cell wall forms the external boundary of the cell; mitochondria produces energy from food for the cell ; while the cytoplasm is the fluid content of the cell in which all organelles float.
The endoplasmic reticulum is the part of the cell which forms the basic framework of the cell which folds the cell in its particular shape.
Thus, the endoskeleton of a cell is made up of endoplasmic reticulum, option (B) is correct.

Additional Information:
More information related to the endoplasmic reticulum is as follows:
Endoplasmic reticulum is a membranous channel system that comprises a continuous series of flattened sacs, present inside the cytoplasm of the cell.
The endoplasmic reticulum is called the endomembrane system of the cell. It is the system made up of membranous sheets and tubules.
It consists of a stacked long, flattened, unbranched unit (cisternae) called vesicles and long, isolated, branched units called tubules.
Its primary function is to synthesize, fold, modify and transport the proteins in the cell, while its secondary function is to form the framework for the cells.
The endoplasmic reticulum is evenly distributed in the cell which starts near the nucleus and extends across the cell and thus forms the structure that holds the cell together.

Note:
-The endoplasmic reticulum is essentially of two types namely -
-The rough endoplasmic reticulum (RER) and
-The smooth endoplasmic reticulum (SER)
-Apart from providing structure to the cell, the endoplasmic reticulum helps in the process of protein synthesis, protein folding, lipid synthesis and the storage of calcium.