Question

Sex-linked genes are carried by

• A. Autosomes
• B. X chromosome
• C. Y chromosome
• D. Non-homologous parts of X and Y chromosomes

Answer 1

The correct option is D Non-homologous parts of X and Y chromosomes

Sex-linked genes are that are present on the sex chromosomes and that determine the sex-linked traits and are transmitted from parent to progeny through sex chromosomes only. Chromosome other than sex chromosome is referred to as autosome which controls normal traits of an organism, not the sex-specific traits. The 23${}^{rd}$ pair of human chromosomes is XY chromosomes which are sex chromosomes that carry the genes to determine sex. The homologous part of X and Y chromosomes carry the genes common to both sex while the nonhomologous part carries the genes for the sex-specific and sex-linked traits. Sex-linked genes are specific to both sex and thus cannot be present on the X chromosome which is common to both male and female. A chromosome is absent in females who carry their sex-linked genes on X chromosome. Thus, the correct answer is option D.