what occurs to molecules of dna during mitosis
Genetic recombination
Molecular models of meiotic recombination have evolved over the years as relevant evidence accumulated . A major incentive for developing a fundamental understanding of the mechanism of meiotic recombination is that such understanding is crucial for solving the problem of the adaptive function of sex , a major unresolved issue in biology . A recent model that reflects current understanding was presented by Anderson and Sekelsky , and is outlined in the first figure in this article . The figure shows that two of the four chromatids present early in meiosis ( prophase I ) are paired with each other and able to interact . Recombination , in this version of the model , is initiated by a double - strand break ( or gap ) shown in the DNA molecule ( chromatid ) at the top of the first figure in this article . However , other types of DNA damage may also initiate recombination . For instance , an inter-strand cross-link ( caused by exposure to a cross-linking agent such as mitomycin C ) can be repaired by HRR .
Molecular models of meiotic recombination have evolved over the years as relevant evidence accumulated . A major incentive for developing a fundamental understanding of the mechanism of meiotic recombination is that such understanding is crucial for solving the problem of the adaptive function of sex , a major unresolved issue in biology . A recent model that reflects current understanding was presented by Anderson and Sekelsky , and is outlined in the first figure in this article . The figure shows that two of the four chromatids present early in meiosis ( prophase I ) are paired with each other and able to interact . Recombination , in this version of the model , is initiated by a double - strand break ( or gap ) shown in the DNA molecule ( chromatid ) at the top of the first figure in this article . However , other types of DNA damage may also initiate recombination . For instance , an inter-strand cross-link ( caused by exposure to a cross-linking agent such as mitomycin C ) can be repaired by HRR .