Answer Happy

Suppose that the numbers of people in the three blood groups M, MN, N in generation 0 of a population are in the proportions 0.25: 0.3: 0.45, and that the population reproduces generation by generation by a process of random mating. (The M-N blood group system is described in Examples 1.3 and 2.4 of Book 5.) (a) What proportion of members of generation 1 and of subsequent generations will be in each of the blood groups M, MN and N? Assume that the population has been reproducing for several generations. Cathy, whose blood group is MN, and Dennis, whose blood group is not known, have two daughters, Hilary and Jane. (b) (i) Draw up a table showing the possible genotype-genotype combinations for Cathy and Dennis, and their probabilities, together with the possible genotypes of their offspring and the probabilities with which the offspring genotypes occur. (ii) Calculate the probability that Hilary's blood group is M. (iii) Calculate the probability that Hilary and Jane both have blood group M. (c) A test shows that Hilary's blood group is M. (i) Given the information about Hilary's blood group, show that the probability that her father Dennis' blood group is M is 0.4. What is the probability that Dennis' blood group is (1) N, (2) MN? (ii)