What is cell cycle?
Life is a continuous process that passes from one generation to the next, so it is a process of constantly updating and constantly starting from scratch. The life of a cell begins with the division of its mother cell, the formation of its daughter cells, or the death of the cell itself. The formation of daughter cells is usually a sign of the end of a cell division, which refers to the process that occurs from the time when a cell divides to form a daughter cell until the next cell divides to form a daughter cell. In this process, the genetic material of the cell is replicated and equally distributed to the two daughter cells.
Cell cycle is divided into two phases: interval and division.
- Interval: G1, S, G2
G1 (first gap) A period from mitosis to DNA replication, also known as pre-synthesis, which mainly synthesizes RNA and ribosomes. This period is characterized by active metabolism of substances, rapid synthesis of RNA and protein, and a significant increase in cell volume. The main significance of this period is to prepare the material and energy for DNA replication in the next phase S.
The S phase (synthesis) is the DNA synthesis phase, in which, in addition to synthetic DNA, histones are also synthesized. The enzymes required for DNA replication are synthesized during this period.
The second gap period is the late stage of DNA synthesis and is the preparation period for mitosis. During this period, DNA synthesis was terminated, and a large amount of RNA and proteins were synthesized, including tubulin and pro-maturation factors.
- Splitting period: M period - early, middle, late, and late.
The mitosis of cells needs to be anterior, middle, posterior, and terminal, and is a continuous process of division, which is divided into two daughter cells by one mother cell. It usually takes 1 to 2 hours.
Stage G0: A period in which cells that temporarily leave the cell cycle, stop cell division, and perform certain biological functions.
What are the cell cycle applications?
Cell proliferation is an important life feature of an organism, and cells proliferate in a split manner. Single-celled organisms that produce new individuals in a manner that divides cells. Multicellular organisms that produce new cells in the form of cell divisions that are used to replenish cells that are aging or dead in the body.
Multicellular organisms can be transformed into a new multicellular individual by a fertilized egg, through cell division and differentiation. It must be emphasized that by cell division, the replicated genetic material can be evenly distributed into two daughter cells. It can be seen that cell proliferation is the basis for the growth, development, reproduction and inheritance of organisms.
Significance: Cell proliferation is one of the important physiological functions of living cells and an important life feature of organisms. Cell proliferation is the basis for the growth, development, reproduction, and inheritance of organisms.
Mode of division: mitosis, amitosis, meiosis.
- Mitosis is one of the most common forms of division in all eukaryotes such as humans, animals, plants, and fungi, and is the main mode of proliferation of eukaryotic cells.
- Amitosis is the direct division of the nucleus and cytoplasm
- Meiosis is a special mitosis in the formation of germ cells.
Apoptosis refers to the orderly death of cells that are controlled by genes to maintain homeostasis. Apoptosis is different from cell necrosis. Apoptosis is not a passive process, but an active process. It involves the activation, expression and regulation of a series of genes; it is not a kind of autologous injury under pathological conditions. Phenomenon, but a death process that is actively pursued to better adapt to the living environment. When cells undergo apoptosis, like the natural fall of leaves or flowers, this biological observation is expressed by the Greek "Apoptosis", meaning that the natural fall of leaves or flowers can be translated into apoptosis.