Sex-linked Flashcard

Front

What is colorblindness?

Back

Colorblindness is a sex-linked recessive disorder that affects the ability to distinguish certain colors, often red and green.

Front

What are the possible genotypes of a colorblind daughter’s mother?

Back

X^A X^a (carrier) and X^a X^a (affected).

Front

If a normal woman whose father was colorblind marries a man with normal color vision, what percentage of their sons will be colorblind?

Back

50%.

Front

What is hemophilia?

Back

Hemophilia is a sex-linked recessive disorder that impairs the body's ability to make blood clots.

Front

What percentage of daughters will have hemophilia if a woman with hemophilia marries an unaffected man whose father had hemophilia?

Back

0%.

Front

Which genotype represents a male with normal vision?

Back

X^N Y.

Front

What percentage of female offspring will be carriers for a recessive disease if one parent is affected?

Back

50%.

Front

What does it mean for a trait to be sex-linked?

Back

A sex-linked trait is associated with a gene that is located on a sex chromosome, often the X chromosome.

Front

What is the difference between a carrier and an affected individual?

Back

A carrier has one copy of a recessive allele and does not express the trait, while an affected individual has two copies of the recessive allele.

Front

How is colorblindness inherited?

Back

Colorblindness is inherited through the X chromosome; males are more likely to be affected because they have only one X chromosome.