Choose the correct option for the pedigree analysis given below:

Carrier organism refers to an individual,which carries a

$A$ colourblind man has a colourblind sister but a normal brother. What is the phenotype of his parents?

Given below are two statements:
Statement $I$: Sickle cell anaemia and Haemophilia are autosomal dominant traits.
Statement $II$: Sickle cell anaemia and Haemophilia are disorders of the blood.
In the light of the above statements,choose the correct answer from the options given below:

If a color-blind man marries a woman who is homozygous normal for this trait,what will be the genotype of their children?

In humans,a gene located on the $X$-chromosome can be responsible for: