Question

A piece of chromosome is breaks and reinserted in the opposite oriention

Answer 1

Chromosomal rearrangements encompass several different classes of events: deletions, duplications, inversions; and translocations. Each of these events can be caused by breakage of DNA double helices in the genome at two different locations, followed by a rejoining of the broken ends to produce a new chromosomal arrangement of genes, different from the gene order of the chromosomes before they were broken (Figure 8-16a). Consistent with the origin of chromosomal rearrangements by breakage, rearrangements can be induced artificially by using ionizing radiation. This kind of radiation, of which X rays and gamma rays are the most commonly used, is highly energetic and causes numerous double-stranded breaks in DNA.