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  2. Bivalent (genetics) - Wikipedia

    en.wikipedia.org/wiki/Bivalent_(genetics)

    A tetrad is the association of a pair of homologous chromosomes (4 sister chromatids) physically held together by at least one DNA crossover. This physical attachment allows for alignment and segregation of the homologous chromosomes in the first meiotic division. In most organisms, each replicated chromosome (composed of two identical sisters ...

  3. Gene conversion - Wikipedia

    en.wikipedia.org/wiki/Gene_conversion

    Gene conversion is the process by which one DNA sequence replaces a homologous sequence such that the sequences become identical after the conversion. [1] Gene conversion can be either allelic, meaning that one allele of the same gene replaces another allele, or ectopic, meaning that one paralogous DNA sequence converts another.

  4. Genetic recombination - Wikipedia

    en.wikipedia.org/wiki/Genetic_recombination

    [citation needed] While in this formation, homologous sites on two chromatids can closely pair with one another, and may exchange genetic information. [ 6 ] Because there is a small probability of recombination at any location along a chromosome, the frequency of recombination between two locations depends on the distance separating them.

  5. Sister chromatids - Wikipedia

    en.wikipedia.org/wiki/Sister_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 ...

  6. Chromosomal crossover - Wikipedia

    en.wikipedia.org/wiki/Chromosomal_crossover

    These are referred to by a variety of names, including non-homologous crossover, unequal crossover, and unbalanced recombination, and result in an insertion or deletion of genetic information into the chromosome. While rare compared to homologous crossover events, these mutations are drastic, affecting many loci at the same time.

  7. Homologous chromosome - Wikipedia

    en.wikipedia.org/wiki/Homologous_chromosome

    A pair of homologous chromosomes, or homologs, is a set of one maternal and one paternal chromosome that pair up with each other inside a cell during fertilization. Homologs have the same genes in the same loci , where they provide points along each chromosome that enable a pair of chromosomes to align correctly with each other before ...

  8. Polyploidy - Wikipedia

    en.wikipedia.org/wiki/Polyploidy

    Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid.

  9. Chromosome segregation - Wikipedia

    en.wikipedia.org/wiki/Chromosome_segregation

    Chromosome segregation is the process in eukaryotes by which two sister chromatids formed as a consequence of DNA replication, or paired homologous chromosomes, separate from each other and migrate to opposite poles of the nucleus. This segregation process occurs during both mitosis and meiosis. Chromosome segregation also occurs in prokaryotes ...