Appearance of Walnut-Comb in poultry in a cross between pure Pea-Comb and Rose-Comb animals is due to
Appearance of Walnut-Comb in poultry in a cross between pure Pea-Comb and Rose-Comb animals is due to
The correct option is A Duplicate genes
In chickens, comb shape is governed by two
genes. While one gene gives rise to rose comb, another gives rise to pea comb.
Each of these two is dominant over single comb. However, when both are brought
together, a new phenotype ‘walnut’ appears. when both dominant alleles
are present ‘walnut’ phenotype appears and when both recessive alleles are
present ‘single’ comb appears. ‘Rose’ and ‘Pea’ phenotypes appear due to the
presence of different single dominant alleles. If pea (rrPP) and rose (RRpp)
are crossed, F1 birds showed ‘walnut’ comb as it has the dominant
alleles of both the genes P and R.Later on, when the F1 walnut combed
birds were inbred together, in F2 generation there appeared walnut, rose, pea and single
combed fowls. These types occurred in the proportions; 9/16 walnut, 3/16 rose,
3/16 pea and 1/16 single.
It is typical dihybrid
crossSo, the correct option is 'duplicate genes'.
In chickens, comb shape is governed by two genes. While one gene gives rise to rose comb, another gives rise to pea comb. Each of these two is dominant over single comb. However, when both are brought together, a new phenotype ‘walnut’ appears. when both dominant alleles are present ‘walnut’ phenotype appears and when both recessive alleles are present ‘single’ comb appears. ‘Rose’ and ‘Pea’ phenotypes appear due to the presence of different single dominant alleles. If pea (rrPP) and rose (RRpp) are crossed, F1 birds showed ‘walnut’ comb as it has the dominant alleles of both the genes P and R.Later on, when the F1 walnut combed birds were inbred together, in F2 generation there appeared walnut, rose, pea and single combed fowls. These types occurred in the proportions; 9/16 walnut, 3/16 rose, 3/16 pea and 1/16 single.
It is typical dihybrid cross
