when do homologous chromosomes pair up in mitosis
Homologous chromosome Homologous chromosomes do not function the same in mitosis as they do in meiosis. Prior to every single mitotic division a cell undergoes, the chromosomes in the parent cell replicate themselves. The homologous chromosomes within the cell will ordinarily not pair up and undergo genetic recombination with each other.[9] Instead, the replicants, or sister chromatids, will line up along the metaphase plate and then separate in the same way as meiosis II - by being pulled apart at their centromeres by nuclear mitotic spindles.[10] If any crossing over does occur between sister chromatids during mitosis, it does not produce any new recombinant genotypes.[2]
Homologous chromosome In anaphase I of meiosis I the homologous chromosomes are pulled apart from each other. The homologs are cleaved by the enzyme separase to release the cohesin that held the homologous chromosome arms together.[7] This allows the chiasmata to release and the homologs to move to opposite poles of the cell.[7] The homologous chromosomes are now randomly segregated into two daughter cells that will undergo meiosis II to produce four haploid daughter germ cells.[2]
Homologous chromosome Meiosis is a round of two cell divisions that results in four haploid daughter cells that each contain half the number of chromosomes as the parent cell.[9] It reduces the chromosome number in a germ cell by half by first separating the homologous chromosomes in meiosis I and then the sister chromatids in meiosis II. The process of meiosis I is generally longer than meiosis II because it takes more time for the chromatin to replicate and for the homologous chromosomes to be properly oriented and segregated by the processes of pairing and synapsis in meiosis I.[6] During meiosis, genetic recombination (by random segregation) and crossing over produces daughter cells that each contain different combinations of maternally and paternally coded genes.[9] This recombination of genes allows for the introduction of new allele pairings and genetic variation.[2] Genetic variation among organisms helps make a population more stable by providing a wider range of genetic traits for natural selection to act on.[2]
Origin of replication DNA replication may proceed from this point bidirectionally or unidirectionally.[3]