We all have heard about babies switched at bath Blood typing is often used to de
ID: 79879 • Letter: W
Question
We all have heard about babies switched at bath Blood typing is often used to determine the relationship between parents and a child However, sometimes blood typing is inadequate in distinguishing between two inadequate in these cases. DNA typing is used. The DNA sequence contains much more variety than is seen at the phenotypic level (outward traits). This variety can be detected by restriction fragment length polymorphism (RFLP) analysis, by polymerase chain reaction (PGR) with variable tandem repeat regions, or even by the sequencing of short regions of DNA. Unlike a blood type, a person's DNA sequence is as individual as his or her fingerprints (with the exception of identical siblings!) One June 6 at approximately 1 PM, Mrs. Smith, Mrs. Stevenson, and Mrs. Jones each delivered a healthy baby boy at Windham Community Memorial Hospital. At 1:20 PM the hospital's fire alarm sounded. Nurses and orderlies scrambled to evacuate patients, and the three newborns were rushed to safety. After the danger had passed, the hospital staff was distressed to find that in the confusion, they had forgotten which baby was which. Since the babies were moved before receiving their identification bracelets, there was no easy way to identify them Dr. Anne Robinson, head of pediatrics, ordered that DNA typing be performed on the babies and their parents. The DNA typing laboratory looked at two different highly variable chromosome regions. The DNA profiles are shown below. Your job is to decide which baby belongs to which set of parents. To assign a baby to a set of parents, every band in the baby's profile should match a bond from either the mother or the father Not all of the binds in die mother or father's profiles will have a counterpart in the baby's DNA profile. Use a ruler or straight-edge to help you line up the bonds.Explanation / Answer
Answer
Since the DNA of the baby share the DNA of both father and mother, it is easy to identify the exact parents by comparing the DNA bands of the baby with both parent.
Mr and Mrs Smith - Baby 3
The DNA bands in the baby at 75 and 41 bp match with Mrs Smith and at 75 and 115bp match with Mr. Smith.
Mr and Mrs Stevenson - BAby 1
The DNA bands at 40 and 90 bp match exactly with that of Mrs. Stevenson and at 50 and 80bp match with the DNA bands of the father.
Mr and Mrs Jones
The DNA bands of the baby at 55 and 100bp match excatly with the DNA bands of the mother and at 150 and 40bp match with that of father.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.