Question

If b represents the allele for black eyes (dominant) and b represents the allele for orange eyes (recessive), what would be the genotypic ratio of a cross between a heterozygous black-eyed mendalien and an orange-eyed mendalien? if b represents the allele for black eyes (dominant) and b represents the allele for orange eyes (recessive), what would be the genotypic ratio of a cross between a heterozygous black-eyed mendalien and an orange-eyed mendalien? 1 homozygous black (bb): 0 heterozygote (black) (bb): 1 homozygous orange (bb) 1 homozygous black (bb): 1 heterozygote (black) (bb): 1 homozygous orange (bb) 0 homozygous black (bb): 0 heterozygote (black) (bb): 1 homozygous orange (bb) 0 homozygous black (bb): 1 heterozygote (black) (bb): 1 homozygous orange (bb) 2 homozygous black (bb): 1 heterozygote (black) (bb): 1 homozygous orange (bb)

Answer 1

Correct answer: "0 homozygous black (bb): 1 heterozygote (black) (bb): 1 homozygous orange "
By crossing a heterozygous black-eyed individual (one dominant allele and one recessive allele) with a homozygous orange-eyed individual (only recessive alleles), the possible combinations of the gametes from each individual will lead to the ever presence of a recessive allele (the only one that is passed from the homozygous recessive parent) in the offspring, and either a dominant allele or a recessive allele from the heterozygous parent. So, the outcome offspring will either be heterozygous (with a dominant allele from the heterozygous parent) or homozygous recessive (with a recessive allele from the heterozygous parent). It is impossible to form homozygous dominant individuals from this crossing.
So, the resultant genotypic ratio from this crossing is 0 homozygous dominant:1 heterozygous:1 homozygous recessive.