What term describes a characteristic controlled by a gene located on a sex chromosome?

What term describes a characteristic controlled by a gene located on a sex chromosome?

• A. Sex Linkage
• B. X-Linked Inheritance
• C. Mendelian Inheritance
• D. Chromosomal Crossover

Answer: (A)

A trait that is controlled by a gene located on a sex chromosome is described as sex-linked. This term captures that the gene’s position on the sex chromosome, rather than on autosomes, determines the trait. In many organisms, including humans, most sex-linked genes are on the X chromosome. Because males have only one X chromosome, a single recessive allele on that X will be expressed in them, while females have two X chromosomes and can be carriers if they have one recessive allele but express it only if both Xs carry it. Classic examples include color blindness and hemophilia. The other options describe different ideas: X-linked inheritance refers to how such genes are passed between generations, Mendelian inheritance typically applies to autosomal genes with simple dominant-recessive patterns, and chromosomal crossover is a meiotic process that reshuffles genetic material rather than defining a trait itself.

A trait that is controlled by a gene located on a sex chromosome is described as sex-linked. This term captures that the gene’s position on the sex chromosome, rather than on autosomes, determines the trait. In many organisms, including humans, most sex-linked genes are on the X chromosome. Because males have only one X chromosome, a single recessive allele on that X will be expressed in them, while females have two X chromosomes and can be carriers if they have one recessive allele but express it only if both Xs carry it. Classic examples include color blindness and hemophilia. The other options describe different ideas: X-linked inheritance refers to how such genes are passed between generations, Mendelian inheritance typically applies to autosomal genes with simple dominant-recessive patterns, and chromosomal crossover is a meiotic process that reshuffles genetic material rather than defining a trait itself.