Search results
Results from the WOW.Com Content Network
Step 1: RecBCD binds to a double-stranded DNA end. Step 2: RecBCD unwinds DNA. RecD is a fast helicase on the 5’-ended strand, and RecB is a slower helicase on the 3'-ended strand (that with an arrowhead) [ref 46 in current Wiki version]. This produces two single-stranded (ss) DNA tails and one ss loop.
meiosis. produces four genetically unique cells, each with half the number of chromosomes as in the parent. mitosis. produces two genetically identical cells, each with the same number of chromosomes as in the parent. Meiosis begins with a diploid cell, which contains two copies of each chromosome, termed homologs.
Chromosomal crossover, or crossing over, is the exchange of genetic material during sexual reproduction between two homologous chromosomes ' non-sister chromatids that results in recombinant chromosomes. It is one of the final phases of genetic recombination, which occurs in the pachytene stage of prophase I of meiosis during a process called ...
Genetic recombination. A model of meiotic recombination, initiated by a double-strand break or gap, followed by pairing with an homologous chromosome and strand invasion to initiate the recombinational repair process. Repair of the gap can lead to crossover (CO) or non-crossover (NCO) of the flanking regions.
Homology-directed repair ( HDR) is a mechanism in cells to repair double-strand DNA lesions. [1] The most common form of HDR is homologous recombination. The HDR mechanism can only be used by the cell when there is a homologous piece of DNA present in the nucleus, mostly in G2 and S phase of the cell cycle. Other examples of homology-directed ...
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. [10] 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 .
Genetic linkage. Genetic linkage is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction. Two genetic markers that are physically near to each other are unlikely to be separated onto different chromatids during chromosomal crossover, and are therefore said ...
Chiasma (genetics) Crossing over during meiosis, with chiasma shown. In genetics, a chiasma ( pl.: chiasmata) is the point of contact, the physical link, between two (non-sister) chromatids belonging to homologous chromosomes. At a given chiasma, an exchange of genetic material can occur between both chromatids, what is called a chromosomal ...