Which type of crossover event produces all four recombinant chromosomes?
A)single-strand crossover
B)two-strand double crossover
C)three-strand double crossover
D)four-strand double crossover
E)None of the above; all crossover events produce a combination of parental and recombinant chromosomes.

Question

Quizplus · Accepted Answer

A four-strand double crossover involves two homologous chromosomes each with double stranded breaks simultaneously migrating well beyond the normal pairing region. This creates two pairs of sister chromatids that eventually have to come back together again to form two functional chromosomes. The net result is two normal chromosomes, as well as two recombinant chromosomes, which have new combinations of maternal and paternal genes.

Which Type of Crossover Event Produces All Four Recombinant Chromosomes