Cell - How do Normal Cells Grow and Divide?

The Cell Cycle is the sequence of events by which a cell duplicates its genome, synthesizes other constituents, and eventually divides into two daughter cells. It is divided into Interphase and M-Phase (Mitosis).

Interphase is the 'resting phase' where the cell prepares for division. It consists of three sub-phases: $G_1$ (Gap 1), $S$ (Synthesis), and $G_2$ (Gap 2).

During the $S$ phase, DNA replication occurs. The amount of DNA doubles (from $2C$ to $4C$), but the chromosome number remains the same ($2n$).

Mitosis is called equational division because the number of chromosomes in the parent and daughter cells remains the same ($2n \rightarrow 2n$). It consists of Prophase, Metaphase, Anaphase, and Telophase.

Cytokinesis is the physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells.

Growth in multicellular organisms occurs because of Mitosis, which increases the number of somatic cells.

Meiosis is a reductional division where the chromosome number is halved ($2n \rightarrow n$), leading to the formation of gametes (sperm and eggs).