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3.5.4.3. Sex-linked inheritance (two characters)

Inheritance linked to sex (two characters). (Page 20)

Problems involving inheritance linked to sex together with another trait determined by a gene on an autosomal chromosome may also appear. The procedure for its resolution will be the same as we have seen so far.

Genetics problem 155

The albinismis caused by a recessive gene, whereas normal pigmentation is determined by a dominant gene. TheHemophilia is caused by a recessive gene linked to the X chromosome

What types of children and in what proportions can a non-hemophilic albino man have with a normally pigmented woman whose father was a non-albino hemophilic and her mother was a non-hemophilic albino?

Genetics problem 156

In the vinegar fly, the short wings (a) are recessive recessive with respect to the normal character, the long wings (A); and the gene for this wing-size trait is autosomal. In the same insect, the white color of the eyes (b) is produced by a recessive gene located on the X chromosome, with respect to the dominant red color (B).

A female, homozygous for both characters, with long wings and white eyes, is crossed with a male with long wings and red eyes, a descendant of a male with short wings.

a. Give the genotypes of the parents of the cross and their offspring.

b. What proportion of females will be heterozygous for the two characters?