Stages of Mitosis Summary Notes

Stages of Mitosis Simple Notes

Definition of Mitosis:

It is a type of cell division that results in two genetically identical daughter cells, each with the same number of chromosomes as the parent cell.

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Functions of Mitosis

Mitosis is divided into 4 stages such as prophase, metaphase, anaphase, and telophase.

Stage 1: Prophase

Chromosomes condense and when stained it is visible with two identical chromatids called sister chromatids that are joined together at the centromere
The two centrosomes (replicated in the G2 phase just before prophase) move towards opposite poles.
Spindle fibres made up of protein microtubules starts to emerge from the centrosomes (which consist of two centrioles in animal cells)
The nuclear membrane breaks down into small vesicles

Stage 2: Metaphase

Chromosomes line up at the equator of the spindle (also known as the metaphase plate)
Centrosomes reach opposite poles
Spindle fibres attaches to the centromeres of the chromosome
Each sister chromatid is attached to a spindle fibre originating from opposite poles

Stage 3: Anaphase

The sister chromatids are pulled apart at the centromere and move toward opposite poles of the cell.
Spindle fibres begin to shorten.
This separation ensures that each new daughter cell will receive an identical set of chromosomes

Stage 4: Telophase

Chromosomes arrive at opposite poles and begin to decondense back into chromatin
Nuclear envelopes begin to reform around each set of chromosomes
The spindle fibres break down.

During cytokinesis, the cytoplasm divides, resulting in two separate daughter cells, each with a complete set of chromosomes and its own nucleus.