The answer is a pedigree chart.
Pedigree charts are used to explain the occurrence of
particular genes from one generation to the next. It gives enough information
about family disease history. They are used in families to find out the
probability of inheriting some disease. So, if Maria and Juanita are cousins
and the genotypes of other members of their family are known, the pedigree chart
could predict their genotypes. Still, it is not as precisely as DNA test.
