Which one of the following symbols and its representation, used in human pedigree analysis is correct ?

It is said, that the harmful alleles get eliminated from population over a period of time, yet sickle cell anaemia is persisting in human population. Why ?

A colour blind man marries the daughter of a colour blind person. Then in their progeny

Haemolytic jaundice is caused due to a dominant gene but only $10\%$ of the people actually develop the disease. A heterozygous man marries a homozygous normal woman; what proportion of the children would be expected to develop the haemolytic disease