Genetics Problems (Review) 1. In a particular dog, short hair is dominant over long, and dark is dominant over light. One dog is heterozygous for hair length and shows the recessive trait for hair color. Another dog is homozygous dominant for hair length and heterozygous for hair color. Identify the possible phenotypes of the offspring and give the number of each expected. 2. In fruit flies, straight wings is dominant over curly. Show how you would determine if a straight winged fly were heterozygous or homozygous? 3. In guinea pigs rough coat "R" is dominant over smooth coat "r". Black coat "B" is dominant over white coat "b". R and B are independent genes.a) Can two black coat parents produce white coat offspring? Can two white coat parents produce black coat offspring? b)Cross a homozygous rough black animal with a smooth white one. What will be the appearance of the F1; of the F2; of the offspring of a cross of F1back with the rough black parent; with the smooth white parent? 4. In humans, the ability to taste phenylthiourea (PTU) is dominant. "Tasters" (TT) or (Tt) perceive an extremely bitter taste of PTU, while "non tasters" (tt) experience no sensation, or taste. a) What are the genotypes of Mr. and Mrs. Meadowmuffin, who can taste PTU, and who have 3 children, one of whom is a non-taster?
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- Fall '13
- Genetics, Zygosity, black guinea pig, black guinea pigs