This is the partial pedigree showing the transmission of albinism through two generations. The dark symbols represent the presence of the trait phenotypically. Examine the diagram and then answer the following:
1. Is this a dominant or recessive
trait?
2. Is the trait sex-linked?
3. What are the genotypes of the
designated individuals.
ANSWERS:
The fact that the parents of children displaying the trait do not themselves display the trait suggests that the gene is recessive. The fact that females and males show the trait suggests that it is not sex-linked. Indeed, more females show the trait than males in this diagram. The genotypes of 1, 2, 3, and 4 are heterozygous for this condition.