A diseased man marries a normal woman and they get three daughters and five sons. All the daughters were diseased and sons were normal. The gene of this disease is

A diseased man marries a normal woman. They get three daughters and five sons. All the daughters were diseased and sons were normal. The gene of this disease is

Brachydactyly is due to

The theory where ratio between the number of $X$-chromosomes and number of complete sets of autosomes will determine the sex is known as

When normal and mutant alleles are present on opposite chromosomes of homologous pair, the heterozygotes are called as