Sex-Linked Traits Overview

Which sex is more likely to have a recessive, sex-linked trait?

Which parent do sons inherit recessive, sex-linked traits from?

Which type of sex chromosome do you find most sex-linked traits on?

What is the genotype of the man with colorblindness?

What is the genotype of the woman who is a carrier for colorblindness?

What is the chance that the child will be colorblind?

What is the genotype of the male with red eyes in fruit flies?

What is the genotype of the female with white eyes in fruit flies?

What is the chance that there will be an offspring with white eyes?

What is the genotype of the man with hemophilia?

What is the genotype of the female who is homozygous dominant for the trait?

Will any of the offspring of a hemophiliac man and a homozygous dominant woman have the disease?

What is the genotype of the male with barred feathers in chickens?

What is the genotype of the female with nonbarred feathers?

What is the probability of having barred females?

What is the probability of having nonbarred females?

What is the probability of having barred males?

What is the probability of having nonbarred males?

Sex-Linked Traits Overview

Males are more likely to express recessive, sex-linked traits due to their single X chromosome.
Sons inherit recessive, sex-linked traits specifically from their mothers, who may be carriers.

X Chromosome and Sex-Linked Traits

Most sex-linked traits are located on the X chromosome.
Colorblindness in humans is a common example, caused by a recessive allele (Xn for colorblindness, XN for normal vision).

Colorblindness Example

A colorblind man (genotype XnY) with a carrier woman (genotype XNXn) has potential offspring combinations.
Each child has a 50% chance of being colorblind.
There is a 50% chance of a daughter being a carrier and a 50% chance of a son being colorblind.

Eye Color in Fruit Flies

Red eyes (XR) are dominant over white eyes (Xr) in fruit flies.
A red-eyed male (genotype XRY) mating with a white-eyed female (genotype XrXr) can produce offspring.
Offspring's probability of having white eyes is 50%.

Hemophilia and X-Linked Inheritance

Hemophilia is caused by a recessive gene on the X chromosome (Xn = affected, XN = not affected).
A man with hemophilia (genotype XnY) marries a homozygous dominant woman (genotype XNXN).
None of the offspring will inherit hemophilia as the mother does not carry the recessive allele.

Feather Color in Chickens

In chickens, barred feathers (ZB) dominate over non-barred feathers (Zb).
A barred male (genotype ZBW) with a non-barred female (genotype ZbZb) has specific offspring probabilities.
There is a 0% chance for non-barred males and a 100% chance for barred females.

Summary of Probabilities

For barred chickens: 100% females will be barred if they inherit ZB from the male.
Non-barred females and males will have a respective probability of 0% and 100% depending on parental genotypes.

Explore the fascinating world of sex-linked traits, focusing on how these traits are inherited primarily through X chromosomes. Understand the significance of colorblindness and eye color in both humans and fruit flies, while also examining the implications of being a carrier. This quiz will test your knowledge on these genetic concepts and inheritance patterns.