Question

6. In humans, a type of blindness called aniridia (B) is dominant over the normal sighted individual (b). Migraine headache (M) is the result of a different dominant gene. A non-migraining man with aniridia whose mother was not blind marries a normal sighted woman who suffers from migraines but whose father did not. In what proportion of their children would you expect to have both aniridia and migraine to occur? __________

7. A researcher believes, as a result of investigation, that the dark pigmented skin of the pure African is due to two pairs of factors, and that white skin is due to the absence of these factors. Let these factors be represented by AABB and the white skin by aabb. Since no skin is pure white (even in winter!). Assume that A = 30% of black, B = 20%, a = 2%, and b = 1%. Now cross two individuals both with the genotype AaBb. List the percent of color and the number of individuals in each as the result of such a cross.

Answer 1

6) genotype of the non-migraining man with aniridia whose mother was not blind is mmBb ( he has inherited b allele from his mother who was not blind bb).

genotype of normal sighted woman who suffers from migraines but whose father did not is Mmbb ( she has inherited m allele from her father did not have migraines).

mmBb * Mmbb

	mB	mb
Mb	MmBb (aniridia,migraines)	Mmbb ( normal vision, migraine)
mb	mmBb ( aniridia, non-migraining)	mmbb ( normal vision, no- migraine)

the proportion of their children would you expect to have both aniridia and migraine to occur= number of children with both anidiria and migraine/total number=1/4.