Question

which combination of alleles are always involved in the inheritance of a sex-linked trait?

heterozygous alleles
homozygous alleles
alleles that are carried on x and y chromosomes
alleles that are carried on all chromosomes except the x and y chromosomes

Explanation:

Identify the core concept of sex-linked inheritance

Sex-linked inheritance refers to the transmission of traits determined by genes located on the sex chromosomes.

Analyze the role of sex chromosomes

In humans and many other organisms, the sex chromosomes are designated as the \(X\) and \(Y\) chromosomes.

Evaluate the given options

• "heterozygous alleles" and "homozygous alleles" describe zygosity, which applies to both autosomal and sex-linked traits.
• "alleles that are carried on X and Y chromosomes" directly defines sex-linked traits.
• "alleles that are carried on all chromosomes except the X and Y chromosomes" defines autosomal traits.

Answer:

• heterozygous alleles
• homozygous alleles
• alleles that are carried on X and Y chromosomes (Correct answer)
• alleles that are carried on all chromosomes except the X and Y chromosomes