The accompanying figure shows a partial microarray analysis for members of a nuclear family. The eight SNP loci examined are evenly spaced at about 10 Mb intervals on chromosome 4, and they are shown on the microarray in their actual order on this chromosome. For the time being, focus your attention only on the two parents and ignore whether they are affected or unaffected.
a. Write out the complete genotype for all the DNA markers in both parents.
b. The microarray data indicate that one SNP locus has three alleles in this family. Which one?
c. How would you know that these loci are in fact on chromosome 4 and are about 10 Mb apart?
d. About what percentage of the total length of chromosome 4 is present in the region between DNA markers 1 and 8? (Chromosome 4 is 191 Mb long; it is the fourth largest in the human genome.)