Question

Raghu is married to Radha, who was previously married to Varun, now deceased. Varun and Radha conceived one child together and adopted one child. Raghu and Radha have also conceived one child. All members of Radha's current family have had DNA fingerprinting done. Unfortunately the sheet that identified each child has been misplaced. Identify which fingerprint in each lane corresponds to each child.

• A. 1- child of Radha and Raghu; 2- adopted child; 3- child of Radha and Varun
• B. 1- adopted child; 2- child of Radha and Raghu; 3- child of Radha and Varun
• C. 1- adopted child; 2- child of Radha and Varun; 3- child of Radha and Raghu
• D. 1- child of Radha and Varun; 2- child of Radha and Raghu; 3- adopted child

Answer 1

Answer: (B)

While DNA contains material common to all humans, some portions are unique to each individual. These portions, or regions, contain two genetic types (alleles) that are inherited from the person’s mother and father. A person’s DNA profile is made by investigating a number of these regions. Here, child 2 contains one allele similar to Raghu and other similar to Radha. Thus, child 2 is by Raghu and Radha. Child 3 contains one allele similar to Varun and other similar to Radha. Thus, child 3 is by Varun and Radha. Child 1 does not have any matching alleles of Varun and Radha. Hence, child 1 is their adopted child.