On the right is the partial pedigree through several generations of a family afflicted with a disease called microphthalmia. It causes blindness
(the shaded symbols). What can you say about the mode of inheritance of this disease? What is the genotype of the numbered individuals. Put your response below and then scroll up the screen for the answer.
YOUR ANSWER:
This is a sex-linked trait. Only the males were afflicted with the disease. Indeed, out of 9 male offspring, nearly half are affected. Out of 7 females, none are affected. Each of the numbered females is a heterozygous carrier for the disease which indicates that the gene is a sex-linked recessive.