JAMB - Biology (1989 - No. 32)
Which of the following is a sex-linked character?
Sickle-cell anaemia
Tongue rollling
Skin colour
Colour blindness
Explicació
Colour blindness is a sex-linked character, specifically an X-linked recessive trait, meaning the genes responsible for it are located on the X chromosome.
Colour blindness is caused by genes on the X chromosome, and because males only have one X chromosome (XY), a single copy of the recessive gene can cause the condition.