Both husband and wife have normal vision though their fathers were colourblind and mothers did not have any gene for colour blindness. The probability of their daughter becoming colourblind is

Which of the following abnormalities is due to autosomal dominant mutation?

Given is : $X$ is the chromosome with gene for haemophilia and $X$ is the chromosome with normal gene. Which of the following individuals will act as carrier for haemophilia

Recessive characters are expressed

$A$ – Sickle-cell anaemia is sex linked recessive trait

$R$ – This disease is controlled by more that two pair of alleles