Question

how are the alleles for sex - linked traits inherited?
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.

Explanation:

Sex - linked traits are associated with genes on the sex chromosomes (X and Y). Alleles for these traits are inherited from parents to offspring via the X and Y chromosomes. Among the given options, the statement "They are passed from parents to offspring on the X and Y chromosomes" is correct as sex - linked alleles are located on X or Y chromosomes and are transmitted through these chromosomes during inheritance.

Answer:

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