During mating between two strains of Neurospora crassa containing different alleles of the same gene one would expect a 1:1 genotypic ratio in progeny spores,however,approximately 0.1% of the time this ratio strays from the predicted.This phenomenon is called_____________ ___________________.

RecBCD protein has ______________ activity that can nick dsDNA.

During postsynapsis strand exchange in homologous recombination of E.coli,ATP is necessary for _______ clearance from the synapsing DNA.