Which of the following is an example of a sex-linked trait?

Which of the following is an example of a sex-linked trait?

• A. Color blindness
• B. Curly hair
• C. Height
• D. Freckles

Answer: (A)

Color blindness is an example of a sex-linked trait because it is primarily associated with genes located on the X chromosome. Males have one X and one Y chromosome, while females have two X chromosomes. As a result, color blindness is more prevalent in males, as they only have one copy of the X chromosome which carries the gene responsible for color vision. If a male inherits an X chromosome with the color blindness allele, he will express color blindness since there is no corresponding allele on the Y chromosome to mask its effect. In females, two copies of the X chromosome are present, and they would need to inherit the color blindness allele on both X chromosomes to exhibit the trait. In contrast, curly hair, height, and freckles are traits influenced by multiple genes and generally do not have a strong link to sex chromosomes. While these traits can vary in inheritance patterns and might be influenced by environmental factors, they are not specifically tied to the X or Y chromosomes in the way that color blindness is. Therefore, color blindness stands out as the clear example of a sex-linked trait in this context.

Color blindness is an example of a sex-linked trait because it is primarily associated with genes located on the X chromosome. Males have one X and one Y chromosome, while females have two X chromosomes. As a result, color blindness is more prevalent in males, as they only have one copy of the X chromosome which carries the gene responsible for color vision. If a male inherits an X chromosome with the color blindness allele, he will express color blindness since there is no corresponding allele on the Y chromosome to mask its effect. In females, two copies of the X chromosome are present, and they would need to inherit the color blindness allele on both X chromosomes to exhibit the trait.

In contrast, curly hair, height, and freckles are traits influenced by multiple genes and generally do not have a strong link to sex chromosomes. While these traits can vary in inheritance patterns and might be influenced by environmental factors, they are not specifically tied to the X or Y chromosomes in the way that color blindness is. Therefore, color blindness stands out as the clear example of a sex-linked trait in this context.