A human male is heterozygous for two inversions, a pericentric inversion on chromosome I and a paracentric inversion on chromosome II, as shown in the diagram below. Segments of normal chromosomes are labeled with uppercase letters. Segments of inversion chromosomes are labeled with lower case letters.

Assume that the pericentric inversion on chromosome I is 30 cM from breakpoint to breakpoint. Assume that the paracentric inversion on chromosome II is 20 cM from breakpoint to breakpoint. For the quesitons below, BALANCED means segments (i.e., DNA sequences) are present in one copy. UNBALANCED means segments are present in more than one copy or absent.

36. What percentage of gametes are expected to be balanced for both chromosome I and chromosome II DNA?

37. What percentage of gametes are expected to be unbalanced for both chromosome I AND chromosome II DNA?

38. Assume that the male and his spouse (with a fully normal genotype) are trying to have a baby. What percentage of zygotes formed from the males sperm are expected to develop into healthy newborns?

chromsome I Chromosome I Norma l Inversion normal Inversion a B f d WH I os F chromsome I Chromosome I Norma l Inversion normal Inversion a B f d WH I os F