1. In chickens a sex-linked dominant allele causes a feather pattern known as "barred". If a barred hen is mated with a non barred rooster, what will be the feather pattern and sex of the offspring?
2. What are the expected genotypic ratios among the children of a women whose father was a hemophiliac, and whose husband is normal? Under what circumstances is it possible for both a father and his son to be hemophiliacs?
Any help appreciated. Thank you!
2. What are the expected genotypic ratios among the children of a women whose father was a hemophiliac, and whose husband is normal? Under what circumstances is it possible for both a father and his son to be hemophiliacs?
Any help appreciated. Thank you!
-
1. All of the offspring will be barred so the phenotype ratio would be 1 barred female: 1 barred male.
2.
XY= normal male
X^hY= hemophiliac male
XX= normal female
XX^h= normal female (carrier)
X^hX^h= hemophiliac female
(I used the carrot to signify that the "h" was superscripted.)
The genotype ratios would be 1 XX^h : 1XX : 1 X^hY : 1 XY. The mother of the father and son would have to either have hemophilia or be a carrier for both a father and his son to be hemophiliacs.
2.
XY= normal male
X^hY= hemophiliac male
XX= normal female
XX^h= normal female (carrier)
X^hX^h= hemophiliac female
(I used the carrot to signify that the "h" was superscripted.)
The genotype ratios would be 1 XX^h : 1XX : 1 X^hY : 1 XY. The mother of the father and son would have to either have hemophilia or be a carrier for both a father and his son to be hemophiliacs.