Question

The example of $XY$ linked gene inheritance is :

• A. xerodermapigmentosa
• B. colour blindness
• C. haemophilia
• D. hypermetropia

Answer 1

Answer: (A)

Sex linked traits are traits which have genes on sex chromosomes. These are $X$ -linked, Y-linked and $XY$ linked.
$X$-linked genes present on $X$-chromosome, e.g., haemophilia, colourblindness.
$Y$-linked genes present on $Y$ -chromosome e.g., hyper trichosis.
$XY$ linked genes present on $X$ and $Y$ chromosome e.g., xeroderma pigmentosa (a skin disorder).
Hyper metropia is not a sex linked disease. In hyper metropia image is formed behind the retina and disease removed by using convex lens.