What does it mean if a trait is 'sex-linked'?
Why are males more likely to be affected by recessive sex-linked disorders?
Which chromosome typically carries sex-linked traits in humans?
Inheritance of sex-linked traits is most evident in which sex?
If a carrier mother has a son, what is the chance he will express a sex-linked trait?
In humans, hemophilia (h) is a sex-linked recessive trait. If a female who is a carrier for hemophilia marries a male with normal blood clotting (H), what is the probability of having a son with hemophilia?
Achondroplasia is a genetic disorder caused by a dominant allele (A). The recessive allele leads to normal height (a). A heterozygous combination results in dwarfism, while a homozygous dominant combination is lethal and results in the death of the individual.
If two parents with dwarfism have children, what is the expected outcome of their cross?
Lethal: out of 4
Dwarfism: out of 4
Normal: out of 4
Duchene muscular dystrophy is a sex linked trait. A not having this disease is dominant (N) to having this disease (n). A mother who is a carrier for this disease (XNXn) mates with a father that is not affected (XNY) in the cross below.
Based on the Punnett square for the sex linked trait, of males will be affected, and of the females will be affected.
In a Punnett square for hemophilia, what does the genotype XNXn indicate about a female?
Important Note
BB and Bb males = bald
bb males = non bald.
Bb and bb females = non bald. BB females = bald
What is the phenotypic ratio of the surviving mice from the cross above?
In a type of fish, scale color is codominant. Fish with blue scales (BB) crossed with fish with yellow scales (YY) produce offspring with blue-and-yellow scales (BY).
If a blue-scaled fish (BB) is crossed with a yellow-scaled fish, what are the expected phenotypes of their offspring?
Which Punnett square shows a 25% chance of the son having hemophilia?
Which cross results in a 50% chance of the daughter being a carrier for hemophilia?
A woman who is a carrier (XBXb) for Baldness mates with a man who is Bald (XbY), a recessive disease.
What percentage of their offspring will be carriers for baldness?
Show your work.
A woman who is a carrier (XBXb) for baldness mates with a man who is bald (XbY), a recessive disease.
What percentage of their offspring will be bald?
Show your work.
If two heterozygous agouti mice are crossed, what percentage of offspring will NOT survive?
If a homozygous black mouse is crossed with a heterozygous agouti mouse, what percentage of offspring will be heterozygous?
