What happens to an individual cell when it matures?
The life cycle of a cell is called the cell cycle. The cycle progresses from a new cell to one that grows, develops, carries out life processes and ultimately will divide again once it is mature. A mature cell by definition is differentiated or specialized to be a specific type of cell in the body unlike a stem cell which is undifferentiated. An example of a differentiated cell is a muscle cell or a nerve cell.
Depending on the type of cell, it may frequently divide like a skin cell or not divide after becoming mature like a nerve cell.
There are specific controls for the cell cycle which include different chemical signals that must be present to proceed to each stage of the cell cycle. There are checkpoints which allow the cycle to go from one stage to the next. Signals provided by specific chemicals at the correct time allow the cycle to function in a coordinated and organized way.
The cell cycle has the G1, S, G2 and M phases. During G1, a signal is required to cause the cell to proceed through the cycle to the M phase where it will eventually divide to form two daughter cells. If a signal is not present, the cell switches off to a phase where it doesn't divide, known as Go (G naught).
During G1 the cell grows and manufactures organelles. During the S phase, the chromosomes are duplicated to insure a complete set will be provided to each daughter cell at the end of the cell cycle. During G2 the cell grows some more.
Eventually, the cell enters the M or mitosis phase. It will divide to become two daughter cells after cytokinesis occurs. That is, when the cytoplasm is divided into the two daughter cells. These two new cells will enter into the G1 phase of the cell cycle and will someday divide once they grow and become mature.
The verb "mature" refers to something or someone becoming fully developed, such as an unripe banana maturing into a ripe banana, or a puppy maturing into a dog. In these examples, a young or early form of the organism fully develops into a useful or desirable state (a ripe banana for eating) or an adult form capable of reproduction (dog).
The word "mature" is not completely accurate when referring to biological cells, because cells do not have an immature and mature form. Instead, one cell divides into two other cells, which are typically identical to the original cell. This process of cell division is called mitosis, in which a mother cell becomes two daughter cells.
In the process of mitosis, the mother cell duplicates its DNA, which is then divided equally between the daughter cells, so each daughter cell receives a complete copy of the original DNA. The cell membrane, organelles (specialized structures within the cell), fluid, and other molecules within the cell are divided between the daughter cells. The daughter cells are typically identical to each other and the mother cell, unless errors such as genetic mutations occur during division.
The fate of the daughter cells depends largely on the type of cell. A cell may
- continue to grow until undergoing mitosis again,
- live until it dies a premature death (necrosis), such as when a cell is damaged, or
- live until it dies a "preprogrammed death" (apoptosis), in which a cell dies in a series of highly controlled steps. This process can be a form of protection against disease or culling of old or unneeded cells.
- This answer only refers to individual cells that are not sex (reproductive) cells. Sex cells undergo a similar but distinct process of cell division called meiosis.
- If you are interested in single-celled organisms (bacteria, archaea, etc.), then I suggest you look into binary fission, the process by which bacteria and some single-celled organisms divide as a form of reproduction.
- If you are interested particularly in how a single cell (an egg fertilized by a sperm cell) becomes a multicellular organism, then I suggest you read more about embryology.