Assume that x is a new mutant allele in corn. An x/x plant is crossed with a triple-10 individual (trisomic for chromosome 10 only) carrying only wild-type dominant alleles at the X locus (Cross 1). Trisomic progeny for chromosome 10 are recovered and crossed back to the x/x plant (Cross 2).
(a) What ratio of dominant to recessive phenotypes is expected if the X locus is not in chromosome 10? (Hint: Write out the parental and progeny genotypes for the X locus for both Cross 1 and Cross 2 keeping in mind that it is not on chromosome 10).
(b) What ratio of dominant to recessive phenotypes is expected if the X locus is in chromosome 10? (Hint: Write out the parental and progeny genotypes for the X locus for both Cross 1 and Cross 2 keeping in mind that it now is on chromosome 10).