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In eukaryotes, there are two distinct types of cell division: a vegetative division , producing daughter cells genetically identical to the parent cell, and a cell division that produces haploid gametes for sexual reproduction , reducing the number of chromosomes from two of each type in the diploid parent cell to one of each type in the ...
Finally, one copy of the genomes is segregated into each daughter cell at the mitosis or M phase. [2] These daughter copies each contains one strand from the parental duplex DNA and one nascent antiparallel strand. This mechanism is conserved from prokaryotes to eukaryotes and is known as semiconservative DNA replication.
The different stages of mitosis altogether define the mitotic phase (M phase) of a cell cycle—the division of the mother cell into two daughter cells genetically identical to each other. [3] The process of mitosis is divided into stages corresponding to the completion of one set of activities and the start of the next.
Three types of cell division: binary fission (taking place in prokaryotes), mitosis and meiosis (taking place in eukaryotes).. When cells are ready to divide, because cell size is big enough or because they receive the appropriate stimulus, [20] they activate the mechanism to enter into the cell cycle, and they duplicate most organelles during S (synthesis) phase, including their centrosome.
In eukaryotic cells (cells that package their DNA within a nucleus), chromosomes consist of very long linear double-stranded DNA molecules. During the S-phase of each cell cycle ( Figure 1 ), all of the DNA in a cell is duplicated in order to provide one copy to each of the daughter cells after the next cell division.
The eukaryotic cell cycle consists of four distinct phases: G 1 phase, S phase (synthesis), G 2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm and cell membrane divides forming two daughter cells.
Mitosis divides the chromosomes in a cell nucleus. During mitosis chromosome segregation occurs routinely as a step in cell division (see mitosis diagram). As indicated in the mitosis diagram, mitosis is preceded by a round of DNA replication, so that each chromosome forms two copies called chromatids .
In mitosis, the sister chromatids separate into the daughter cells, but are now referred to as chromosomes (rather than chromatids) much in the way that one child is not referred to as a single twin. Schematic karyogram of a human, showing a diploid set of chromosomes as seen in the G 0 and G 1 phases of the cell cycle (before DNA synthesis ...