$A$ normal-visioned man,whose father was color-blind,marries a woman whose father was also color-blind. What is the probability that their first child,a daughter,will be color-blind (in $\%$)?

What will be the percentage of affected sons,whose father is colour-blind and mother is normal (in $\%$)?

Albinism is a congenital disorder resulting from the lack of the enzyme:

$A$ man whose father was colour blind marries a woman who had a colour blind mother and normal father. What percentage of male children of this couple will be colour blind (in $\%$)?

Which one of the following techniques is employed in human genetic counselling?

Given below is a pedigree chart of a family with five children. It shows the inheritance of attached earlobes as opposed to the free ones. The squares represent the male individuals and circles the female individuals. Which one of the following conclusions drawn is correct?