Cell division mitosis and cytokines in self-replicating cells, the paired centrioles are located near the nucleus within the centrosome. They are rod-shaped bodies that are perpendicular to one another. Each centriole is made up of nine microtubule triplets on the inside. The centrosome complex, which contains the centrioles, directs the creation of the mitotic spindle during cell division. Centrioles are also known as basal bodies because they create the cell extensions known as cilia and flagella. Other substances and structures found in the cytoplasm of cells include stored meals (glycogen granules and lipid droplets), pigment granules, different crystals, water vacuoles, and swallowed foreign objects. However, because these are not part of the cell’s active metabolic machinery, they are referred to as inclusions.
Mitosis and cytokinesis are the two events that occur during cell division in all cells other than bacteria. Mitosis is the division of the mother cell’s copied DNA into two daughter cells. Cytokinesis is the division of the cytoplasm that occurs near the end of mitosis. Although mitosis is usually accompanied by cytokinesis, the cytoplasmic division may not occur in some cases, resulting in the formation of binucleate or multinucleate cells. This is a fairly common occurrence in the human liver.
Mitosis produces two daughter nuclei that are genetically identical to the mother nucleus. This distinguishes mitosis from meiosis, a type of nuclear division that only occurs in reproductive organs (testes or ovaries).
Meiosis, which produces four daughter nuclei that differ genetically from the mother nucleus, is only used to produce gametes (eggs and sperm) for sexual reproduction. The purpose of cell division in the body, which includes mitosis and cytokinesis, is to increase the number of cells for growth and repair while preserving their genetic heritage.
Mitosis has four phases: prophase, metaphase, anaphase, and telophase.
During the growth period of the body, cell division is critical. Until puberty, when normal body size is achieved and overall body growth ceases, most cells divide. Only cells that have been subjected to abrasion (epithelium of the skin and lining of the gut) continue to divide routinely after this point in life. Other cell populations, such as liver cells, cease to divide but retain this ability if some of them are removed or damaged. Skeletal muscle, cardiac muscle, and the majority of mature neurons almost completely lose this ability to divide and are thus severely harmed by injury. The body retains its ability to repair cuts and wounds as well as replace some of its aged cells throughout life.