Male pattern baldness is a/an..... trait.

Match the terms in Column-$I$ with their descriptions in Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$(A)$ Dominance	$(1)$ Many genes govern a single character.
$(B)$ Co-dominance	$(2)$ In a heterozygous organism, only one allele expresses itself.
$(C)$ Pleiotropy	$(3)$ In a heterozygous organism, both alleles express themselves fully.
$(D)$ Polygenic inheritance	$(4)$ $A$ single gene influences many characters.

Which of the following statements are correct?
$(a)$ The $X$-linked genes are located on the non-homologous region of $X$-chromosomes.
$(b)$ Females with the recessive gene on one $X$-chromosome are carriers.
$(c)$ The carrier female is also severely affected by the disorder.
$(d)$ $Y$-linked genes are located on the homologous region of $Y$-chromosome.
$(e)$ Human males have homomorphic sex chromosomes.
Choose the correct option.

What is true for the expression of recessive characters?

Sickle-cell anemia has not been eliminated from the African population because,........

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

List-$I$	List-$II$
$(A)$ Two or more alternative forms of a gene	$(I)$ Back cross
$(B)$ Cross of $F_1$ progeny with homozygous recessive parent	$(II)$ Ploidy
$(C)$ Cross of $F_1$ progeny with any of the parents	$(III)$ Allele
$(D)$ Number of chromosome sets in plant	$(IV)$ Test cross

Choose the correct answer from the options given below: