In humans,sex-linked characters are mainly transmitted through:

$A$ 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

From the chromosomal complements given below,identify the one which shows female heterogamety.

$A$ hereditary disease which is never passed on from father to son is

In which of the following is the male monosomic $(XO)$?

$A$: Holandric traits are passed from one generation to the next generation.
$R$: These traits appear more frequently in one sex than in other.