Lois and Peter, who are each NOT trisomic for chromosome 21, are awaiting the birth of a 2nd child (Chris). Given their age, the probability of Down's syndrome is 1/20. Down's syndrome is seen...

Extracted text: Lois and Peter, who are each NOT trisomic for chromosome 21, are awaiting the birth of a 2nd child (Chris). Given their age, the probability of Down's syndrome is 1/20. Down's syndrome is seen individuals with 3 copies of chromosome 21. Peter and Lois want to know if their 2nd child has trisomy-21. Prenatal genetic screening was conducted by genotyping Lois, Peter, and the unborn child (Chris) with a RFLP marker for chromosome 21. Genotyping was also conducted on their first born (Meg): The results of the RFLP are shown below: Are the test results indicative of a trisomy-21 in Chris? If no, explain your reasoning. If ves. explain vour reasoning and describe in which parent and which meiosis did the nondisjunction occur. Lois Peter Meg Chris