4. In a family of five children, what is the probability that:
a. all are males?
b. three are males and two are females?
c. two are males and three are females?
d. all are the same sex?
5. In assessing data that fell into two phenotypic classes, a geneticist observed values of 250:150. She decided to perform a χ2 analysis by using the following two hypotheses: (a) the data fit a 3:1 ratio, and (b) the data fit a 1:1 ratio. Calculate the χ2 values for each hypothesis. What can be concluded about each hypothesis?
6. Pigment in mouse fur is only produced when the C allele is present. Individuals for the cc genotype are white. If color is present, it may be determined by the A and a alleles. AA or Aa results in agouti color, while aa results in black coats.
a. What F1 and F2 phenotypic ratios are obtained from a cross between an agouti mouse (AACC) and a white mouse (aacc)?
b. In three crosses between agouti females whose genotypes were unknown and white males of the aacc genotype, the following litters were obtained:
(1) 8 agouti (2) 9 agouti (3) 4 agouti
8 white 10 black 5 black
What is are the genotypes of the females?