Answer:
possession of a single X chromosome increases the likelihood that a male will express a defective copy of the genes that cause this set of genetic disorders
Explanation:
In humans, there are two types of sex chromosomes: X and Y. After fertilization, females receive two X chromosomes, while males receive one X and one Y chromosome. Sex-linked inheritance refers to phenotypic traits associated with genes located on a sex chromosome (either the X chromosome in both males and females or the Y chromosome exclusively in males). Sex-linked disorders/diseases are generally associated with mutations on the X chromosome (because the X chromosome is larger and contains more genes than the Y chromosome), and usually affect males because they contain only one copy of this chromosome. In these cases, females that have a single mutation on one X chromosome often have a normal phenotype due to the presence of the normal allele expressed from the other X chromosome.
