What is mitosis?
The division of a single cell into two identical cells is known as “mitosis” in biology. The word “identical” describes how the genetic makeup and number of chromosomes are the same in both cells are the same. Preprophase (in plant cells), prophase, prometaphase, metaphase, anaphase, and telophase are the stages. Since these phases appear to overlap, it is unclear when each phase starts or ends. However, separate events characterize each of them.
Originally, the term “mitosis” solely referred to nuclear division—which is the division of the cytoplasm—without cytokinesis, as in the case of some cells, such as those of some fungi and the fertilized eggs of many insects. The phrases “mitosis” and “cell division” are frequently employed in the modern era. As there is another type of cell division that also involves the sex cells—meiosis—it is not always appropriate in the strictest sense.
Explain the stages of mitosis.
The somatic cells undergo mitosis, particularly at the nucleus. Following a series of mitotic events, the cell divides into two completely identical daughter cells. The phases move forward in the following order: prophase, prometaphase, metaphase, anaphase, and telophase. However, a preprophase occurs in plant cells before prophase. Take note of how the animal cell divides when mitosis closes. A cleavage furrow develops in the center of the cell, splitting it in half.
Prophase:
A centromere connects the two chromatids that make up each chromosome, which is genetically identical. During DNA replication, chromatin is a loosely organized form of genetic material. DNA must, however, be packed more firmly during mitosis to make anaphase separation easier. To aid in this, chromatin starts to condense into chromosomes at the beginning of prophase.
Spindles associated also start to develop. Microtubule-based structures known as mitotic spindles help organize and arrange chromosomes. The centrosome, an organelle, is where the spindles are connected. Two centrosomes are present in each cell during mitosis, and during prophase, they start to migrate in opposing directions.
Prometaphase:
The chromosomes completely condense into their compact state at this point. The kinetochore, a location where spindle fibers can adhere to chromosomes when the nuclear envelope starts to degrade, becomes accessible (an area of the centromere found on each sister chromatid). The sister chromatids connect the two by being joined by spindles that come from the opposing centrosome.
Metaphase:
At this point, the chromosomes line up along what is known as the metaphase plate, a hypothetical line. After finishing their movement, the centrosomes are now situated at the cell’s extreme extremities. The cell will now verify that each chromosome is correctly connected to its kinetochores and that it is aligned along the metaphase plate.
Sister chromatids are more evenly distributed amongst the two daughter cells as a result of this. A chromosomal alignment or spindle attachment fault will cause the cell to stop growing until the issue is resolved.
Anaphase:
Sister chromatids are pushed to the cell’s opposite ends during this phase. The chromatids at the centromere are broken and moved to the opposite poles of the cell as the spindle fibers constrict. The cell will lengthen to prepare for division when spindle fibers are not connected to chromatids.
Telophase:
The cell has lengthened and is almost done dividing during this phase. Re-appearing cell-like characteristics include the reformation of two nuclei (one for each cell). The chromosomes then decondense, and the fibers of the mitotic spindle are disassembled.
Cytokinesis:
The division of the cytoplasm into two new cells is known as cytokinesis. In reality, this phase starts between anaphase and telophase, but it doesn’t end until after telophase. A protein ring called the actin ring pinches the cytoplasm along a ridge called the cleavage furrow to divide the two cells. The cytoplasm is divided equally between the two cells as a result.
What is the function of mitosis?
The two key purposes of mitosis are as follows:
The asexual reproductive process in single-celled organisms is called mitosis.
The replacement of harmed tissues is aided by mitosis. When they cannot feel the neighboring cells, the cells close to the injured cells start mitosis. The dividing cells overlap with one another and protect the harmed cells.
What is the importance of mitosis?
- The process of mitosis is what transforms the zygote into an adult.
- Chromosomes are distributed equally to each daughter cell.
- It is in charge of a person’s growth and development.
- It keeps the number of chromosomes in all of an organism’s bodily cells consistent.
- Asexual reproduction, vegetative plant reproduction, and the repair and regeneration of damaged tissues are all dependent on mitosis.
- Because there is no recombination or crossing over during mitosis, the genome is kept pure.
- Animals’ old and damaged cells, such as the gut epithelium and blood cells are repaired and replaced by it.
References:
https://byjus.com/biology/mitosis/
https://teachmephysiology.com/biochemistry/cell-growth-death/mitosis/
