Two genes govern fleece color and horns in sheep. For the co…
Two genes govern fleece color and horns in sheep. For the coat color gene there are 2 alleles, W and w, and the W allele is fully dominant over the w allele (WW and Ww = white fleece; ww = black fleece). For horns, there are 2 alleles, H and h, with H conferring horns and h conferring hornlessness. However, horns is a sex-influenced trait in sheep. H is fully dominant to h in male sheep (rams), and H is recessive to h in female sheep (ewes). If a population of heterozygous (dihybrid) rams and ewes were bred to each other, what is the expected ratio of phenotype classes in the male and female offspring? Fill in the expected phenotype class ratios for each sex (independently!) in the table below. You have the choice of filling in the table with whole numbers, fractions (X/Y) or percentages (X%) – whatever you feel the most comfortable using. However, be sure to take care that you are putting your numbers next to the intended phenotypes. Male offspring Female offspring Phenotype class Ratio Phenotype class Ratio White Horned [1] White Horned [2] White Hornless [3] White Hornless [4] Black Horned [5] Black Horned [6] Black Hornless [7] Black Hornless [8]
Read DetailsThe yeast Saccharomyces cerevisiae has unordered tetrads. A…
The yeast Saccharomyces cerevisiae has unordered tetrads. A cross between a strain of genotype +bc and a++ was made to study the linkage relationship between 3 genes: a, b, and c. The following tetrads were obtained. Are genes b and c linked? Explain why and include the relevant tetrad numbers.
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