In pedigree analysis, the square, blackened and horizontal lines represents
Female, healthy individual, parents
Female, affected individual, parents
Male, affected individual, parents
Male, affected individual, progeny
Red green colour blindness appears due to
Colour blindness is found more in males than in females because
Given below is a highly simplified representation of the human sex chromosomes from a karyotype. The gene $'a'$ and $'b'$ could be of
If both parents are carriers for thalassaemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?