Colour blindness is a disease usually affecting man but the factor for it is transmitted to the children always by woman. This is because particular factor is located on
$X$ chromosome
$Y$ chromosome
Both $X$ and $Y$ chromosomes
Autosome
Phenylketonuria is a genetic disorder due to a defect in metabolism of the following.
Give scientific reasons : The Mendelian experiments cannot be carried out in human beings.
Sickle -cell anaemia has not been eliminated from the African population because it
Which of the following is not true of haemophilia?
Colour blindness is caused by a single