Question

Jon and Lily are parents of child A; Bob and Jill are parents of child B; and Don and Jess are parents of child C. Children A, B, and C have Down syndrome. A Southern blot is used to analyze the restriction fragment length polymorphisms (RFLPs) of the parents and their children. Since trisomy 21 is the major cause of Down syndrome, a probe complementary to a sequence of chromosome 21 is used for RFLP detection. Thicker bands on the blot indicate the presence of two RFLPs of the same fragment length. Label each child with the nondisjunction event that produced their RFLP pattern

Answer 1

The RFLP patterns of the children can be labeled based on the nondisjunction events that produced them. Thicker bands on the Southern blot indicate the presence of two RFLPs of the same fragment length.

Step-by-step explanation:

The RFLP patterns of the children can be labeled based on the nondisjunction events that produced them. Trisomy 21, which is the major cause of Down syndrome, results from the presence of three copies of chromosome 21. Thicker bands on the Southern blot indicate the presence of two RFLPs of the same fragment length.

Therefore, for Child A, the RFLP pattern indicates that the nondisjunction event resulted in the presence of two RFLPs of the same fragment length. Similarly, for Child B and Child C, the RFLP pattern also suggests the presence of two RFLPs of the same fragment length.