7. Having become an expert in molecular biology, you are asked to give your opin

Question

7. Having become an expert in molecular biology, you are asked to give your opinion to help decide a custody dispute. Two women claim to be the mother of Jane Doe. This child has been found to have an unusual defect in the enzyme ribonuclease. You have isolated this protein using sophisticated laboratory techniques and have found the unusual segment of the enzyme. The amino acids in this segment are as follows: Asp-Ser-Cys-Thr-Ser-Ala-Ala-Phe-Ser-Ser-Asp-Tyr-Cys-Asn-Glu- o A gou know this protein is encoded in a well defined area of the DNA on chromosome #12. You therefore obtain samples of the DNA from chromosome 12 of each of the two women who claim to be the parent of the child. Using this DNA, you are able to isolate the corresponding mRNA. Using the information given earlier (genetic code), try to figure out which of the mRNA segments below could have carried the code for the defective gene. mRNA from woman A: GA UGUACUuccGccGC CCUCUGA UACUGOAAUGAG -Phy-ser mRNA from woman B: GACUCAUe ACUUCCGCCGCAUcGUccucuGAQUACUGCGAUGAG Based on the evidence that you have collected, which woman could be the natural mother of the baby Jane Doe? A) Woman A B) Woman B C) Neither Woman A nor Woman B

Explanation / Answer

mRNA from woman A have carried the code for the defective gene as all the triplet gentic codons in the mRNA from woman A are exactly corrsponding to the sequence of amino acids present in the protein syntheisized by defective gene. While mRNA from woman B encodes for a protein which is differ by three amino acids from the given sequence of amino acids for defective ribonuclease gene. In the given sequence the third amino acid is cysteine while the corresponding codon in woman B is UCU which codes for serine. The eighth amino acid is phenyl alanine while the corresponding codon in woman B is UCG which codes for serine. The second last amino acid is Asn and the corresponding codon in B is GAU which codes for Asp.

Based on these observation woman A is the natural mother of the baby Jane Doe.

Related Questions

Navigate

• Browse (All)
• Browse 7
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.