SexLinked Traits Inheritance of SexLinked Traits o o

Inheritance of Sex-Linked Traits o o o X-linked Disorders – the allele is on

X-Linked Traits Colorblindness is an X-linked recessive disorder. ex: X X - female, normal

Colorblindness is an X-linked recessive disorder. Show a cross between a female who is

X-Linked Traits Hemophilia is an X-linked recessive disorder. ex: X X - female, normal

Show a cross between a female who is a carrier of hemophilia with a

Hemophilia is x-linked recessive. Suppose that a man with hemophilia marries a woman who

Hairy ears is a Y-linked trait. Suppose that a man with hairy ears marries

Blood type inheritance is somewhat complicated, with three forms of the gene and 4

Blood Types: Suppose a woman with blood type AB marries a man who is

Slides: 10

Download presentation

Sex-Linked Traits

Inheritance of Sex-Linked Traits o o o X-linked Disorders – the allele is on the X chromosome, it occurs mainly in males because the mother usually donates the recessive allele and since males only have one X chromosome they get the disorder automatically Carriers – are individuals who are heterozygous for an inherited disorder but do not show symptoms of the disorder; they can pass the allele for the disorder on to their offspring; seen only in x-linked disorders Y-linked Disorders – the allele is on the Y chromosome, therefore males have the disorder because they only have Y chromosomes; there are no carriers for y-linked disorders.

X-Linked Traits Colorblindness is an X-linked recessive disorder. ex: X X - female, normal Xc. X - female, normal o (carrier for colorblindness) Xc. Xc - female, colorblind X Y - male, normal Xc. Y - male, colorblind

Colorblindness is an X-linked recessive disorder. Show a cross between a female who is colorblind a male who is not. X c XX Y c XY X c Xc X Xc Y How many are colorblind? 50% How many are carriers? 50%

X-Linked Traits Hemophilia is an X-linked recessive disorder. ex: X X - female, normal Xh. X - female, normal o (carrier for hemophilia) Xh. Xh - female, hemophilia X Y - male, normal Xh. Y - male, hemophilia

Show a cross between a female who is a carrier of hemophilia with a male who has the disorder. X X h h XX Y Xh. Y X h XX XY How many have hemophilia? 50% How are carriers of hemophilia? 25% How many are normal? 25%

Hemophilia is x-linked recessive. Suppose that a man with hemophilia marries a woman who does not have the disorder. n What are the chances that their offspring will have hemophilia? h 0% X Y h XY X XX X XXh XY

Hairy ears is a Y-linked trait. Suppose that a man with hairy ears marries a woman with normal ears. n What are the chances that their offspring will have hairy ears? h 50% Can females have hairy ears? No n X Y h X XX XY X XX XYh

Blood type inheritance is somewhat complicated, with three forms of the gene and 4 possible phenotypes. (A, B, AB, O) o o o AB AA - Homozygous A AO - Heterozygous A BB - Homozygous B BO - Heterozygous B OO

Blood Types: Suppose a woman with blood type AB marries a man who is heterozygous B. What are the chances that their children will have blood type A? 25% blood type B? 50% A B blood type AB? 25% B AB BB O AO BO