A more dramatic example of a sex-influenced trait is male pattern baldness. Because mostly men are affected, one might guess that it is a sex-linked trait. A classic case of male pattern baldness appears in President Adams's family. The second U.S. president, John Adams, and his son John Quincy Adams, the sixth president, as well as the latter's son and grandson, all had male pattern baldness. If this trait was on the X chromosome, as figure 3.2 shows, a father could not pass the trait onto his sons, meaning they must have received the trait from their mothers. However, it would be quite a coincidence if all four of the mothers of the individuals listed above were carriers of male pattern baldness. Actually, male pattern baldness is also a sex-influenced trait. The difference in the appearance of the trait is due to the hormonal differences between men and women. Thus in men the trait behaves as a dominant trait, while in women it behaves as a recessive trait.
Was this article helpful?
The best start to preventing hair loss is understanding the basics of hair what it is, how it grows, what system malfunctions can cause it to stop growing. And this ebook will cover the bases for you. Note that the contents here are not presented from a medical practitioner, and that any and all dietary and medical planning should be made under the guidance of your own medical and health practitioners. This content only presents overviews of hair loss prevention research for educational purposes and does not replace medical advice from a professional physician.