Daughter cells are cells that are produced as a part of the process of cell division. Depending on whether cells are dividing in mitosis or meiosis, the daughters can be genetically identical to the parent cell or they may be different. The ability to replicate and divide cells is key to life on Earth, used for everything from renewing skin cells in the human body to allowing bacteria to duplicate themselves for asexual reproduction. There are a number of different ways that cells can divide to produce daughter cells.
In mitosis, genetically identical copies of a cell are produced. The process starts with replication of the genetic material inside the parent cell to create two complete sets. Once this process is over, the cell splits in half to create two new cells. Each cell should contain genetically identical information and should function just like the parent cell. If a mistake happens during mitosis, the resulting cells may self-destruct or be attacked by the immune system. In rare cases, the cells live and pass the mistake down to future daughter cells, resulting in problems like cancer.
With meiosis, the genetic material is mixed up during the initial division and replication. The cells divide again to produce four haploid cells, each containing half of the genetic information used to code for a complete organism. These cells are known as gametes and they are used in sexual reproduction. When two gametes join, they create an embryo with a full set of genetic information. The cells within the embryo can begin multiplying, dividing, and differentiating to make a new organism.
Cells can only undergo a certain number of divisions before they become senescent and stop dividing. The usual number of divisions is 52, and it is known as the Hayflick Limit. This limitation is created by the gradual shortening of special sections of DNA known as telomeres. The telomeres are located on the ends of the chromosomes and during each division, they grow a little bit shorter. Eventually, they become so short that division would cut into genetic material needed for coding new cells, and a cell can't divide any more.
The daughter cells that result from cell division provide a method for multicellular organisms to continually renew themselves as cells become tired and damaged. Cell division happens constantly throughout the body to create a fresh supply of cells. When cell division goes wrong, the parent organism can develop medical problems.