GENETICS: upcoming final exam. please help. 8 The pedigree below shows the inher
ID: 301340 • Letter: G
Question
GENETICS: upcoming final exam. please help.
8 The pedigree below shows the inheritance of an autosomal recessive disorder in humans. Shown below the pedigree (and lined up by individual) are the Southern blot data for two RFLP loci for this autosome. One RFLP has alleles of either 7 kb or 5 kb and is revealed by digestion with the restriction enzyme BamHI; the other gives either a 4 kb or 3 kb EcoRI fragment. L2 1 2 3 4 56 7 8 9 10 11 12 17 kb BamHT 3 kb Which RFLP locus is more closely linked to the disease gene? For the loci that you think is more closely linked, which individual is likely to be recombinants? 7kb "nututedExplanation / Answer
Answer: The RFLP locus which has the digestion site for BamHI is more closely linked to the disease.
Explanation: To be a recessive diseased indidual, he must be genetically homozygous. So, individual 1 (Parent) is heterozygous, where as individual 2 (Parent) homoyzgous. After digestion with Bam HI and EcoRI individual 1 shows two bands (5,7 & 4,3) in each case where as individual 2 shows two bands in both the cases at 5kb and 4 kb. Now, by using this reference we should analse the genetic alle pattern of the individuals.
BamHI EcoR1
Offspring 1: positive negative
Offspring 2: positive negative
Offspring 3 : negative Positive
Offspring 4: positive Positive
Offspring 5: Positive Positive
Offspring 6: Positive Negative
Offspring 7: Positive Negative
Offspring 8: Positive Positive
Offspring 9: Positive Positive
Offspring 10: Negative Negative
Offspring 11: Positive Positive
Offspring 12: Positive Positive
From the table we can conclude, BamHI result is more accurate and closely linked to the disease.
Individual 3, and individual 10 for the offsprings are likely to be recombinants.
Explanation: From the more accurate BamHI result we can observe, individual 3 is homozygous but showing bands for heterozygosity, where as individual 10 shows homozygosity but actually it is heterozygous individual.
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