The Ability to roll the tongue is determined by dominant gene while the recessive gene results in the inability to roll the tongue.
A man and his wife can both roll their tongues and are surprised to find there son cannot. Explain this by showing the genotype of all three persons.
The wife and husband are heterozygous, therefore, they have one dominate allele and one recessive allele. The little boy inherited both recessive alleles so he can't roll his tongue. T = Dominate allele t = recessive allele
