Among Delta-back stripped sh, there are two genes that segregate independently of one another. Suppose the alleles at the rst locus are A (dominant) and a (recessive) and the alleles at the second locus are B (dominant) and b recessive). If an AABB sh mates with an aabb sh, and their offspring are inter-crossed, the proportion of F2 sh that show either a dominant phenotype at the rst locus and a recessive phenotype at the second locus OR a recessive phenotype at the rst locus and a recessive phenotype at the second locus is:-