Question

Genetics Problems #4 1) Janet and her siblings have attached earlobes (recessive trait). However, her mother has free earlobes (dominant trait). What is the genotype of her mother? - 2) Charlie has a straight little finger (recessive trait), but his parents don't. What is the phenotypic ratio among the parent's children? 3-4) Abraham is adopted. He has hair on the back of his hand (dominant trait). Could both of his biological parents have had hair on the back of their hand? Could both of his biological parents have had no hair on the back of their hand? Explain. 5) Jackie and Max both have a widow's peak (dominant trait). Can they have a child without a widow's peak? Explain. 6) If a cross gives a 2:2 phenotypic ratio, what are the genotypes of the parents? 7) What is the phenotypic ratio of a dihybrid cross? Phenotypic ratio: 8) Sally's mother is heterozygous for Huntington's disease (Hb). Sally's father doesn't have Huntington's disease. What are the chances that Sally will have Huntington's disease? 9) What is the percentage of pink snapdragon flowers in the Fl generation showing incomplete dominance? 10) A husband and wife both have attached earlobes (ce). What are the chances their son will have free earlobes (Ec)? 11-12) Stephanie has normal color vision. Her husband Chris also has normal color vision. They have a son that is color blind and a daughter that has normal color vision. What is the genotype of the mother, father, son and the daughter?

Answer 1

Hello,

1)The genotype of the mother would be Ee(one dominant and one recessive allele).Only then she can express dominant trait and her children can show recessive trait.

2)

Parents are heterozygous dominant and the phenotypic ratio of their children will be 3:1.

Hope this helps.