Question

Splice" or crossover products can form after the resolution of Holliday junctions during homologous recombination between two nearly identical parental duplexes. Which of the following answers best describes the characteristics of these recombination products? "Splice" or crossover products can form after the resolution of Holliday junctions during homologous recombination between two nearly identical parental duplexes. Which of the following answers best describes the characteristics of these recombination products?

A) Each product contains heteroduplex DNA in the region of recombination, while the genes in the flanking regions do not become reassorted.
B) Each product contains homoduplex DNA in the region of recombination, while the genes in the flanking regions become reassorted.
C) One product contains heteroduplex DNA in the region of recombination, while the other contains homoduplex DNA in this same region. The genes in the flanking regions of both products become reassorted.
D) Each product contains heteroduplex DNA in the region of recombination, while the genes in the flanking regions become reassorted.

Answer 1

The correct answer is option A.

Step-by-step explanation:

At the time of the strand invasion phase of homologous recombination, an entering single strand from one parental duplex produces a novel region of heteroduplex DNA with the complementary single strand from the other parental duplex. As the two parental duplexes are not same, these regions can comprise mismatched base pairs.

These novel heteroduplex DNA regions are extended at the time of branch migration. If cleavage of the Holiday junction lead to reassortment of the genes adjoining the recombination region, then the outcomes are known as crossover products or splice.