Why do developmental scientists believe that the male sex is associated with a higher cumber of sex-linked inherited disorders?

Because the male possesses only one X chromosome and the female has two, any mutation on one X chromosome will result in a sex linked disease, as the female has another X chromosome that may be intact, preventing the sex linked disease from being expressed on the female. On the other hand, if a male carries a mutation on the one X chromosome, there is no second X chromosome that may have the intact information.

Hemophilia and color blindness are two examples of sex-related diseases that affect men more frequently than women. The X chromosome contains the information needed to make planet cells; a male with an error in this gene will have trouble clotting and stopping bleeding. The X chromosome also contains the information needed to make color-detecting cones, which makes men far more likely to be color blind.

Developmental scientists believe that the male sex is associated with a higher number of sex-linked inherited disorders because males have only one X chromosome, making them more susceptible to recessive X-linked disorders since they lack a second X chromosome to mask the expression of these disorders.