Question

Explain the importance of understanding cells in order to understand the whole body. Construct an arguement with 3 key points and support each of them with examples.

Answer 1

The cells are the functional units of living systems. A group of cells make up different types of tissues. Different tissues are formed into different organelles. Different organelles for various organ systems and these organ sytems carryout the metabolic activities.

Some cells are involved in protective action or provide immunity to the body. For example the B cells produce antibodies against infectious agents. The T cells eliminate the pathogens through phagocytosis (macrophages).

Some cells (blood cells) carry the oxygen and nutrients throughout the body and are involved transportation.

Some cells carryout the function of communication. The hormone cells bound to the receptor cellsof a specific organ elicit a suitable response.

Some cells are involved in storage function, the cells of liver and muscle store glycogen, while the cells of adipose tissue store the fats.

There are numerous and various functions carriedout by the cells to continue the metabolic activities and help the survival of living beings.

Answer 2

The three basic principles of cell theory are,

1. Cells are the smallest structural units of all living organisms.

2. Cell division is the basis for growth and reproduction. So, cells are produced by the division of pre-existing (primordial or stem cells) cells.

3. Cells are the smallest functional units of all living organisms, which perform all the vital functions.

Group of atoms (and subatomic particles) form a molecule, group of molecules form a macromolecule, group of macromolecules form an organelle, group of organelles form a cell, group of cells form a tissue, group of tissues form an organ, group of organs form an organ system, organ systems group to form an organism.

We have approximately 200 different cell types in our body, which perform various functions. Based on the structure and functions of the cell, they are called as nerve cells, cardiac cells, hepatocytes (of liver) etc. depend upon the organelles present in the cell, its function varies. For example, a skeletal muscle cell contains many mitochondria, but a red blood cell is completely lack of mitochondria.