Q45 - Multiple Alleles in Mallard Duck Plumage
Refer to the question paper for figures and tables.
Q45. If F1 progeny yield 50% restricted, 25% mallard, and 25% dusky ducks, what are the parental genotypes?
M^R m^d x M m^d: The 50% restricted : 25% mallard : 25% dusky ratio requires one parent to be heterozygous restricted/dusky (M^R m^d) producing M^R and m^d gametes equally, and the other to be heterozygous mallard/dusky (M m^d). The cross gives: 1/4 M^R M (restricted), 1/4 M^R m^d (restricted), 1/4 M m^d (mallard, since M > m^d), 1/4 m^d m^d (dusky). This produces 50% restricted, 25% mallard, 25% dusky.