The results shown are from a DNA test for four genes used in a paternity identification case. DNA for the mother (M) and her child (C) are shown along with DNA from two possible fathers, F1 and F2. Based on the exclusion principle, is either man excluded as the possible father? Explain.

Verified step by step guidance

1. Understand the exclusion principle in paternity testing: a man can be excluded as the biological father if he does not share at least one allele with the child at any of the tested gene loci, considering the mother's contribution.
2. For each gene locus, compare the alleles of the mother (M) and the child (C) to determine which allele the child inherited from the mother and which allele must have come from the father.
3. At each locus, check the alleles of each possible father (F1 and F2) to see if they have at least one allele matching the child's paternal allele (the allele not inherited from the mother).
4. If a possible father lacks the paternal allele at any locus, he is excluded as the biological father based on the exclusion principle.
5. Summarize the findings by identifying if either F1 or F2 is excluded or if both remain possible fathers based on the allele comparisons across all loci.

Key Concepts

Exclusion Principle in Paternity Testing

The exclusion principle states that if a man lacks one or more genetic markers that the child must have inherited from the father, he can be excluded as the biological father. This principle relies on comparing specific gene loci between the child, mother, and potential fathers to identify mismatches.

Genetic Markers and Alleles

Genetic markers are specific DNA sequences used to compare individuals in paternity tests. Each person inherits one allele from each parent at a gene locus. By analyzing these alleles in the mother, child, and potential fathers, one can determine if the child’s alleles could have come from the tested men.

Inheritance Patterns of Autosomal Genes

Autosomal genes are inherited equally from both parents, with one allele coming from the mother and one from the father. Understanding this pattern is essential to identify which alleles in the child must have originated from the father, enabling exclusion or inclusion of potential fathers based on allele matches.