 Whether recombination in the DSBR pathway results in chromosomal crossover is determined by how the double Holliday junction is cut , or " resolved " . Chromosomal crossover will occur if one Holliday junction is cut on the crossing strand and the other Holliday junction is cut on the non @-@ crossing strand ( in Figure 4 , along the horizontal purple arrowheads at one Holliday junction and along the vertical orange arrowheads at the other ) . Alternatively , if the two Holliday junctions are cut on the crossing strands ( along the horizontal purple arrowheads at both Holliday junctions in Figure 4 ) , then chromosomes without crossover will be produced . 
