In Drosophila,the recessive alleles for brown and scarlet eyes (of two independent genes)interact so that bw/bw;st/st is white.If a pure-breeding brown is crossed to a pure-breeding scarlet,what proportion of the F₂ will be white?

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The cross between a pure-breeding brown (bw/bw;+/+) and a pure-breeding scarlet (st/st;+/+) will produce F1 offspring that are all heterozygous for both traits (bw/+;st/+). When these F1 individuals are crossed (F1 x F1), the proportion of offspring that are homozygous recessive for both traits (bw/bw;st/st) and thus white-eyed is 1/4 (for bw/bw) * 1/4 (for st/st) = 1/16.

In Drosophila,the Recessive Alleles for Brown and Scarlet Eyes (Of