Question

In this set of questions, you will need to be able to apply inheritance patterns of two different characters/genes. One gene is inherited in a sex-linked pattern, while the other gene is inherited through an autosomal gene. (Answer choices include 0, 0.25, 0.5, 0.75, and 1.)

In this set of questions, you will need to be able to apply inheritance patterns of two different characters/genes. One gene is inherited in a sex-linked pattern, while the other gene is inherited through an autosomal gene. The sex-linked gene determines red-green color blindness and is due to an X-linked recessive allele in humans. A widow's peak (a hairline that comes to a peak in the middle of the forehead) is due to an autosomal dominant allele. Consider the following family history: • A man with a widow's peak and normal color vision marries a color-blind woman with a straight hairline. • The man's father had a straight hairline, as did both of the woman's parents. Use the family history to make predictions about the couple's children. Suppose the couple had a daughter with normal color vision and a widow's peak. What is the probability that she is heterozygous for both genes genes? [Select] What is the probability that any son the couple has will be color blind with a straight hairline? [Select] What is the probability that any daughter that the couple has will be color blind with a widow's peak? [Select] If the couple has a child, what is the probability that it will be a son with a widow's peak? [Select]

Answer 1

From the family history we obtain the genotype of the couples

1) The probability that the daughter with normal color vision and widow's peak who is heterozygous for both gene is 1(100%). Because there is only one daughter with widow's peak and normal vision in F1.

2)The probability that any son the couple has with colorblindness and straight hairline will be 0.5(50%).Because the couple has two sons.Out of these two sons one has colorblindness and straight hairline.

3)The probability that any daughter the couple has with colorblindness and widow's peak will be zero.Because the couple will produce two daughters.Out of these two daughters none of them have colorblindness with widow's peak.

4)The prbability that the couple has a child which must be a son with widow's peak will be 0.25(25%).Because they will produce 4 offspring.Out of these offspring only one child who is a male with widow's peak.

I am providing the cross here

Father Aa X Y and mother aaxcxc Ay widow's peak ay straight hairline x as colour blind XC - Normal vision cross between Aax'y and a axcx Gametes are from mother from father a xe 1. Aqxx Ааху аа х“х зах“ у т. Female with male with mare with Female with widow's peak straight hair widow's peak straight hair and normal and colour and normal and colour blindness vision vision blindness