1) Black coat color is a dominant trait in guinea pigs. A black female guinea pig was testcrossed and produced 6 offspring, all black. What is her probable genotype? With what degree of confidence can her genotype be specified?
Answer: There's a 98.4% chance that she's BB.
2) Shorthorn cattle with the genotype CRCR are red, cattle with the CWCW genotype are white, and CRCW cattle are "roan." If roan cattle show 35% of the coloration of red cattle, and white are essentially colorless,what is the degree of dominance? Which allele is dominant?
Answer: CW (white) is dominant, D =
0.3
3) Homozygote TMTM individuals are said to have "thalassemia major" and generally die in childhood of severe anemia. Heterozygotes TMTN have "thalassemia minor," a mild anemia, and generally survive. What fraction of the adult offspring of two parents with thalassemia minor are expected to be anemic?
Answer: 2/3
4) Vestigial wings and ebony body color result from independently-assorting recessive mutations in Drosophila. If a pair of VvEe flies are mated and produce 256 progeny, how many are expected to show ebony body color and normal wings?
Answer: 48