a) Consider a cross between a pea plant that is heterozygous for round seeds and a pea plant that has wrinkled seeds. The allele for round seeds (R) is dominant over that for wrinkled seeds (r). Using a Punnett square, determine the genotypes of the offspring.
b) In guinea pigs, the black coat (B) is dominant over the white coat (b), and straight hair (H) is dominant over curly hair (h). Using a Punnett square, complete the cross between a heterozygous black, curly-haired individual and a homozygous straight-haired, white individual. State the parent genotypes and gametes, and the F1 phenotypes and genotypes.
c) Hypophosphatemia is a dominant genetic disorder caused by a deficiency of phosphates in the blood. Assuming the other parent is free of the disorder, males with the disorder will pass it on to all their daughters, but not their sons. Females with the disorder will pass it on to approximately half of their children.
- Is this pattern of inheritance autosomal or sex-linked? Explain.
- Draw Punnett squares to show the inheritance pattern of the disorder in each of the two scenarios.