Genetics Problems

Genetics Problems -3 HOW TO DO GENETICS PROBLEMS 1. Assign a letter for each allele. (dominant traits – capital letter, recessive traits – lower case letter) 2. Determine the genotype of each parent. 3. Determine the possible gametes of each parent. 4. Use a Punnett square to determine the possible genotypes of the offspring. 5. Use the offspring genotypes to determine the phenotypes. SEX and SEX-LINKED 1. A couple are expecting their first baby. What are the chances that the baby will be a boy? 2. A certain couple have three boys and are expecting their fourth child. What are the chances that it will be a boy? 3. Hemophilia is an X-linked recessive genetic disorder. A normal woman, whose father had hemophilia, married a normal man. What is the chance of hemophilia in their daughters? In their sons? 4. The factor for color blindness is recessive. X" is a normal chromosome for normal vision. X’ is an X chromosome carrying a gene for color blindness. A woman of genotype X X would have normal vision. A woman with genotype X X would be color-blind. A man of genotype X Y would have normal vision; a man of genotype XY would be color-blind. Two normal-visioned parents produce a son who is colorblind. What are the genotypes of the parents? 5. A girl with normal vision whose father was color-blind marries a color-blind male. What will be the nature of their children with respect to color blindness?