In chickens, comb shape is determined by alleles at two loci. A
walnut comb is produced when at least one dominant allele
A is present at one locus and at least one
dominant allele B is present at the second locus.
A rose comb is produced when at least one dominant allele is
present at the “A-locus” and two recessive alleles are present at
the “B-locus”. A pea comb is produced when two recessive alleles
are present at the “A-locus” and at least one dominant allele is
present at the “B-locus”. When the genotype is a double homozygous
recessive, a single comb is produced.   

Give the phenotypic ratios that will results from the following
crosses: AaBb x aaBb