In humans,pattern baldness is a type of ....... trait.

$A$ human male is heterozygous for autosomal genes $A$ and $B$ and is also hemizygous for the $hemophilia$ gene. What proportion of his sperm will be $abh$?

Which of the following phenomena leads to variation in $DNA$?

If a daughter is affected by hemophilia,which of the following possibilities applies to her parents?

Identify the correct and incorrect statements from the following:
$(1)$ Mendel is considered the father of modern genetics.
$(2)$ Down's syndrome is a sex-linked chromosomal disorder.
$(3)$ Sickle cell anemia is an example of point mutation.
$(4)$ Color blindness is a hereditary trait.
$(5)$ Triploid female flies are found in Drosophila.

$A$ couple has sons who are colourblind with $AB$ blood group. Identify the parents from the following.