Sex-influenced characters are due to

Match List-$I$ with List-$II$ :

List-$I$	List-$II$
$A$. Incomplete Dominance	$I$. Human skin colour
$B$. Co-dominance	$II$. Inheritance of flower colour in Antirrhinum sp.
$C$. Pleiotropy	$III$. Phenylketonuria disease in humans
$D$. Polygenic inheritance	$IV$. $ABO$ blood group

Choose the correct answer from the options given below :

State how many of the given statements are correct.
$(1)$ In a dihybrid cross experiment,Mendel obtained a test cross ratio of $1:1:1:1$.
$(2)$ Coupling and repulsion were first explained by Bateson and Punnett.
$(3)$ Klinefelter syndrome is a sex-chromosomal disorder occurring in females.
$(4)$ Mendel selected $7$ pairs of contrasting traits in pea plants to explain his experiments.
$(5)$ The chromosomal theory of inheritance was first proposed by Sutton and Boveri.

Match the Column-$I$ with Column-$II$:

Column-$I$	Column-$II$
$(a)$ Pleiotropic gene	$(i)$ Both alleles express equally
$(b)$ Co-dominance	$(ii)$ Change in nucleotide
$(c)$ Epistasis	$(iii)$ One gene shows multiple phenotypic expression
$(d)$ Mutation	$(iv)$ Non-allelic gene interaction

Milk secretion and beard growth,both the traits are

In a cross between genotypes showing recessive epistasis,the $F_2$ phenotypic ratio will be .....