Cell Division and Mitosis notes by BHS

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Cell division is the fundamental process by which new cells are formed. It ensures growth, repair, and reproduction in living organisms.

After the completion of the cell cycle (S-phase, G2-phase, and M-phase), the division of chromosomes (karyokinesis) occurs, followed by the division of cytoplasm (cytokinesis). Based on how cells divide, there are three main types of cell division:

1. Mitosis


2. Meiosis


3. Amitosis




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Mitosis

Definition

Mitosis is the exact replication of a parent cell into two identical daughter cells. Each daughter cell has:

The same number and type of chromosomes,

Identical DNA content,

The same hereditary instructions as the parent cell.


Occurrence

In somatic cells of animals (body cells).

In meristematic tissues of plants for the multiplication of undifferentiated cells.


Key Features

Produces two genetically identical diploid cells.

Ensures growth, tissue repair, and asexual reproduction in many organisms.

Involves a series of well-defined changes that occur as a newly formed cell grows and divides.


Phases of Mitosis

Mitosis is broadly divided into two phases:

1. Interphase – The preparatory phase (includes G1, S, G2).


2. M-phase – The actual division phase (karyokinesis + cytokinesis).

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