Arrange the following plants with respect to an increasing number of chromosomes:
Rice,Maize,Apple

$A$: Pseudoalleles are actually closely linked genes.
$R$: These can be identified easily as both affect different characters,providing separate phenotypes.

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

Read all the given statements carefully and determine the number of correct statements.
$(1)$ Mutations are not hereditary.
$(2)$ Male $Drosophila$ flies do not show crossing over.
$(3)$ In honeybees,the male bee is diploid.
$(4)$ In a frame-shift mutation,one nitrogen base is replaced by another nitrogen base at a specific position.
$(5)$ Genes are responsible for inheritance.

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.

How do genetic disorders arise? Explain by giving suitable examples.