Unformatted text preview: 138 Chapter 4 • Eukaryote Chromosome Mapping by Recombination a. Is the nail-patella syndrome a dominant or recessive phenotype? Give reasons to support your answer. b. Is there evidence of linkage between the nail- patella gene and the gene for ABO blood type, as judged from this pedigree? Why or why not? c. If there is evidence of linkage, then draw the alle- les on the relevant homologs of the grandparents. If there is no evidence of linkage, draw the alleles on two homologous pairs. d. According to your model, which descendants are recombinants? e. What is the best estimate of RF? f. If man III-1 marries a normal woman of blood type O, what is the probability that their first child will be blood type B with nail-patella syndrome? Solution a. Nail-patella syndrome is most likely dominant. We are told that it is a rare abnormality, so it is unlikely that the unaffected people marrying into the family carry a pre- sumptive recessive allele for nail-patella syndrome. Let N be the causative allele. Then all people with the syndromebe the causative allele....
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This note was uploaded on 01/10/2011 for the course BIOL BIOL taught by Professor Johnson during the Spring '08 term at Aberystwyth University.
- Spring '08