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Meiosis is divided into meiosis I and meiosis II which are further divided into Karyokinesis I, Cytokinesis I, Karyokinesis II, and Cytokinesis II, respectively. The preparatory steps that lead up to meiosis are identical in pattern and name to interphase of the mitotic cell cycle. [ 10 ]
Cytokinesis illustration Ciliate undergoing cytokinesis, with the cleavage furrow being clearly visible. Cytokinesis (/ ˌ s aɪ t oʊ k ɪ ˈ n iː s ɪ s /) is the part of the cell division process and part of mitosis during which the cytoplasm of a single eukaryotic cell divides into two daughter cells.
Interphase is the process through which a cell must go before mitosis, meiosis, and cytokinesis. [15] Interphase consists of three main phases: G 1 , S , and G 2 . G 1 is a time of growth for the cell where specialized cellular functions occur in order to prepare the cell for DNA replication. [ 16 ]
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.
Telophase accounts for approximately 2% of the cell cycle's duration. Cytokinesis typically begins before late telophase [1] and, when complete, segregates the two daughter nuclei between a pair of separate daughter cells. Telophase is primarily driven by the dephosphorylation of mitotic cyclin-dependent kinase (Cdk) substrates. [2]
The bridge is then broken and resealed to form two identical daughter cells during cytokinesis. The breakage is formed by microtubules and the resealing is negated by calcium dependent exocytosis using Golgi vesicles. [2] In comparison, the plant cell septum and the animal cell mid-zone are analogous.
Crossing over is important for the normal segregation of chromosomes during meiosis. [2] Crossing over also accounts for genetic variation, because due to the swapping of genetic material during crossing over, the chromatids held together by the centromere are no longer identical. So, when the chromosomes go on to meiosis II and separate, some ...
Chromosome segregation occurs at two separate stages during meiosis called anaphase I and anaphase II (see meiosis diagram). In a diploid cell there are two sets of homologous chromosomes of different parental origin (e.g. a paternal and a maternal set).