Mitosis: Definition, Features, Stages

Mitosis Definition

“Mitosis is the cell cycle phase in which newly generated DNA is divided into two new cells with the same number and type of chromosomes as the parent nucleus.”

Mitosis is an asexual reproductive mechanism in unicellular organisms. Continue reading to learn more about mitosis and the many stages it goes through.

What is Mitosis?

Cell division is the primary driving force behind cellular reproduction. There are cell division mitosis and meiosis. Most eukaryotic cells divide in such a way that the ploidy, or the number of chromosomes, remains constant, with the exception of germ cells, which contain half the number of chromosomes.

Mitosis is the division of a cell’s nucleus into two nuclei, each with an equal amount of genetic material, during the cell cycle. Following the G2 phase, the nucleus separates, followed by cytoplasmic division.

Mitosis is required for both cell development and cell replacement. DNA can be tampered with as a consequence of mitosis anomalies, leading to genetic diseases.

Features of Mitosis

1. This method does not include segregation or combining
2. Mitosis in plants promotes the growth of vegetative plant components such as root tips, stem tips, and so on
3. The cell is also known as equational cell division since the parent and daughter cells have the same chromosomal number
4. Two daughter cells are generated from the parent cell during each cycle of cell division

Stages of Mitosis

Phases have been defined for the processes that occur during mitosis. The cell spends the bulk of its time in interphase before entering prophase, preparing for the commencement of mitosis (the DNA is copied). Prophase is technically the initial stage of this process because the genuine process includes nucleus division. During cell division, there are various stages of mitosis that occur:

Interphase

A cell spends a period of its growth in interphase before commencing mitosis. When in interphase, it passes through the following phases:

• G1 Phase: That’s the time preceding DNA synthesis
• S Phase: That’s the phase in which DNA synthesis occurs
• G2 Phase: The period between the termination of DNA synthesis and the start of prophase

Prophase

Prophase follows the S and G2 phases of the cycle and is marked by the condensation of genetic material to form compact mitotic chromosomes made up of two chromatids linked at the centromere.

The beginning of the development of the mitotic spindle, proteinaceous cytoplasmic, and microtubule components that help in the process marks the end of prophase. The nuclear envelope starts to break down.

Prometaphase

The nuclear envelope disintegrates during the prometaphase. Microtubules can now reach from the centromere to the chromosome. The microtubules connect to the kinetochores, allowing the cell to transport the chromosome.

Metaphase

The microtubules start tugging on the chromosomes with equal vigour at this point, and the chromosome ends up at the cell’s centre. This region is known as the metaphase plate. As a consequence, each cell is given a complete genome.

Anaphase

Anaphase starts with the split of sister chromatids. These sister chromatids develop into the chromosomes of the daughter nuclei. The fibres linked to each chromosome’s kinetochores then drag the chromosomes to the pole. The centromere of each chromosome leads at the edge, while the arms lag behind.

Telophase

The chromosomes that have gathered at the two poles begin to merge into an undifferentiated mass as the nuclear membrane develops around it. Following prophase, the nucleolus, golgi bodies and ER complex reappear.

Cytokinesis, or the splitting of the cytoplasm into two daughter cells, occurs once telophase has occurred. As a result, it signifies the completion of cell division.

Functions of Mitosis

Mitosis serves two critical functions:

• Mitosis is a process that helps an organism develop. In single-celled organisms, mitosis is the asexual reproduction process
• Mitosis supports the replacement of damaged tissues. When the cells adjacent to the injured cells do not detect the neighbouring cells, they start mitosis. The dividing cells reach out to each other and cover the damaged cells

Significance of Mitosis

1. In animals, mitosis is responsible for the repair and regeneration of old and damaged cells, such as gut epithelial cells and blood cells
2. Mitosis contributes to genomic purity by preventing recombination and crossover
3. Mitosis is essential for asexual reproduction, vegetative propagation, and the repair and regeneration of damaged tissues in plants
4. It keeps the number of chromosomes consistent in all bodily cells of an organism
5. It is in charge of an individual’s growth and development
6. Equal chromosomal distribution to each daughter cell
7. Mitosis is in charge of the zygote’s growth into an adult