Why do sex-linked traits occur in males more often than females and give an example.

Female = X chromosome

X chromosome

Male = Y chromosome

X chromosome

If the offspring Is male the father passes on Y chromosome.

If the trait is recessive and carried on the X chromosome then because the males only have one X chromosome the trait will be expressed, this is why they have a much higher chance of inheriting the trait, whereas if it was a female who inherited the recessive trait the other X chromosome she has can provide genes that are damaged or missing.

E. g. Haemophilia

Red-green colour blindness

Duchenne muscular dystrophy