Question

how are the alleles for sex - linked traits inherited?
○ they are passed from the y chromosome in parents to the x chromosome in offspring.
○ they are passed from the x chromosome in parents to the xy chromosome in offspring.
○ they are passed from parents to offspring on the x and y chromosomes.
○ they are passed from any chromosome in the parents to the x or y chromosome in the offspring.

Explanation:

Sex - linked traits are determined by genes located on the sex chromosomes (X and Y). Alleles for these traits are passed from parents to offspring on the X and Y chromosomes. For example, in humans, color - blindness is a sex - linked trait. Males (XY) have one X and one Y chromosome. Females (XX) have two X chromosomes. If a female has a recessive allele for a sex - linked trait on one X chromosome, she may be a carrier. Males, having only one X chromosome, will express the trait if they inherit the recessive allele on their single X chromosome.

Answer:

They are passed from parents to offspring on the X and Y chromosomes.