Cell is the basic structural and functional unit of life / all living organsims.
When its time for development and maturity it undergoes Cell cycle.
Each dividing cells passes through a cycle. The sequence of events a cell undergoes from the end of one cell division to the end of next cell division is called Cell Cycle.
It may also be defined as those changes which occur during cell growth and cell division.
The cell cycle involves two distinct phases as Interphase and Mitotis [M-Phase]
The Need for New Cells
To divide, each new cell has to undergo a phase of GROWTH and DEVELOPMENT.
It is after this phase that the cell attains enough maturity and can complete all metabolic processes that are necessary before entering the phase of cell division.
This preparatory phase of cells is termed as Inter-phase followed by cell division MITOSIS.
Body Cells are also known as Somatic Cells and the type of cell division seen in them is Mitosis / Homotypic cell division in which the number of chromosomes remains as their parent cell. i.e. for humans the body cells possess 46 chromosomes and during Mitosis the number of chromosomses in the newly formed daughter cells are also 46
Reproductive Cells are also known as Germ Cells. The type of cell division seen in them is Meiosis ( it undergoes 2 cell division i.e.First Heterotypic Cell division and Second Homotypic cell division).
In Heterotypic Cell division the number of chromosomes becomes half i.e. it reduces.
While in Homotypic Cell division the number of chromosomes it remains same.
At the end of Meiosis the total number of daughter cells formed are 4 having haploid number of chromosomes.
E.g. in humans the reproductive cells undergoes Meiosis. 46 number of chromosomes in the Germinal Epithelial cells undergoes first Heterotypic Cell division forming 2 cells having 23 number of chromosomes i.e. half than its parent cell.
Then it undergoes Homotypic cell division with same number of chromosomes forming 4 daughter cells.