Mitosis is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis is an equational division which gives rise to genetically identical cells in which the total number of chromosomes is maintained. Mitosis is preceded by the S phase of interphase and is followed by telophase and cytokinesis, which divide the cytoplasm, organelles, and cell membrane of one cell into two new cells containing roughly equal shares of these cellular components. The different stages of mitosis altogether define the mitotic phase of a cell cycle—the division of the mother cell into two daughter cells genetically identical to each other.
Onion cells in different phases of the cell cycle enlarged 800 diameters. a. non-dividing cells b. nuclei preparing for division (spireme-stage) c. dividing cells showing mitotic figures e. pair of daughter-cells shortly after division
A cell in late metaphase. All chromosomes (blue) but one have arrived at the metaphase plate.
Ciliate undergoing cytokinesis, with the cleavage furrow being clearly visible
An abnormal (tripolar) mitosis (12 o'clock position) in a precancerous lesion of the stomach (H&E stain)
The cell cycle, or cell-division cycle, is the series of events that take place in a cell that causes it to divide into two daughter cells. These events include the duplication of its DNA and some of its organelles, and subsequently the partitioning of its cytoplasm, chromosomes and other components into two daughter cells in a process called cell division.
Onion (Allium) cells in different phases of the cell cycle. Growth in an 'organism' is carefully controlled by regulating the cell cycle.
Overviews of the G1/S transition control networks in plants, animals, and yeast. All three show striking network topology similarities, even though individual proteins in the network have very little sequence similarity.
Image: Paul Nurse portrait
Image: Tim hunt
