In the following symbols used in human pedigree analysis,identify the symbol that denotes consanguineous mating.

In humans,color blindness is caused by:

$A$ normal-visioned woman, whose father is colour-blind, marries a normal-visioned man. What would be the probability of her sons and daughters being colour-blind? Explain with the help of a pedigree chart.

Genetic counsellors can identify heterozygous individuals by

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:

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?