A woman with two genes (one on each X-chromosome) for haemophilia and one gene for colour blindness on the X-chromosomes marries a normal man. How will the progeny be?

Question

A woman with two genes (one on each X-chromosome) for haemophilia and one gene for colour blindness on the X-chromosomes marries a normal man. How will the progeny be? (A) All sons and daughters haemophilic and colourblind (B) Haemophilic and colourblind daughters (C) 50 % haemophilic colourblind sons and 50% haemophilic sons (D) 50 % haemophilic daughters and 50 % colour blind daughters

Tardigrade Admin · Accepted Answer

Haemophillia and colour blindness both are recessive X-linked traits. They express in males when present in single copy (heterozygous) but in females, they express only when present in homozygous condition.
Results:
(a)

50%

sons are colourblind and haemophilic.
(b)

50%

sons are haemophilic only.
(c)

50%

daughters are carrier for colour blindness and haemophilia.
(d)

50%

daughters are carrier for haemophilia only.

Q. A woman with two genes (one on each X-chromosome) for haemophilia and one gene for colour blindness on the X-chromosomes marries a normal man. How will the progeny be?

All sons and daughters haemophilic and colourblind

Haemophilic and colourblind daughters

$50%$ haemophilic colourblind sons and 50% haemophilic sons

$50%$ haemophilic daughters and $50%$ colour blind daughters

Q. A woman with two genes (one on each X-chromosome) for haemophilia and one gene for colour blindness on the X-chromosomes marries a normal man. How will the progeny be?

All sons and daughters haemophilic and colourblind

Haemophilic and colourblind daughters

50% haemophilic colourblind sons and 50% haemophilic sons

50% haemophilic daughters and 50% colour blind daughters

$50%$ haemophilic colourblind sons and 50% haemophilic sons

$50%$ haemophilic daughters and $50%$ colour blind daughters