What is the process of mitosis?

Mitosis is the process by which a single eukaryotic cell divides to produce two genetically identical daughter cells. It is essential for growth, tissue repair, and asexual reproduction. The process can be broken down into several distinct stages:

1. Interphase (Preparation phase):

G1 phase (Gap 1): The cell grows and carries out its normal metabolic functions. It also prepares the necessary proteins and organelles for DNA replication.

S phase (Synthesis): DNA replication occurs, resulting in two identical copies of each chromosome, now called sister chromatids.

G2 phase (Gap 2): The cell continues to grow and prepares for mitosis by synthesizing proteins and other components needed for division.

2. Prophase:

Chromosomes condense and become visible under a microscope as tightly coiled structures.

The nuclear membrane begins to break down.

The mitotic spindle (a structure made of microtubules) begins to form, extending from the centrosomes (regions in the cell that organize the microtubules).

Centrioles (in animal cells) move to opposite poles of the cell.

3. Metaphase:

The chromosomes align along the metaphase plate, an imaginary line in the middle of the cell.

The spindle fibers attach to the centromeres of the chromosomes via kinetochores, specialized protein complexes.

4. Anaphase:

The sister chromatids are pulled apart toward opposite poles of the cell. This happens when the centromere splits, and the spindle fibers shorten, separating the chromatids.

Each chromatid is now considered a separate chromosome.

5. Telophase:

Chromosomes reach the opposite poles of the cell and begin to de-condense back into chromatin.

The nuclear membrane reforms around each set of chromosomes, creating two distinct nuclei in the cell.

The spindle fibers disintegrate.

6. Cytokinesis:

Cytokinesis is the division of the cytoplasm that occurs at the end of mitosis.

In animal cells, a contractile ring of actin filaments forms and pinches the cell membrane, dividing the cell into two daughter cells.

In plant cells, a cell plate forms between the two nuclei, eventually developing into a new cell wall, dividing the cell into two.

At the end of mitosis and cytokinesis, two genetically identical daughter cells are produced, each with the same number of chromosomes as the original cell.