Identify the odd one among the following disorders.

$A$ colour-blind son will be born when:

Which one of the following is a dominant trait?

Which of the following disorders is caused by a qualitative defect in the synthesis of globin molecules, leading to impaired $O_2$ transport?

Both a man and a woman are affected by Vitamin $D$-resistant rickets,which is an $X$-linked dominant trait. All the daughters of this couple are affected by rickets,but some of the sons are not. What are the genotypes of the parents?

Which one of the following traits shows criss-cross inheritance?