Why is it that asexual reproduction produces exact copies, but sometimes minor variations are also seen in the next progeny?

In human males,all the chromosomes are paired perfectly except one. These unpaired chromosomes are:
$(i)$ Large chromosome
$(ii)$ Small chromosome
$(iii)$ $Y-$ chromosome
$(iv)$ $X-$ chromosome

$(i)$ Name the scientist who proposed the theory of evolution of species by natural selection.
$(ii)$ What conclusion did Mendel draw from his experiments regarding traits?
$(iii)$ Arrange the following organisms in the order of their evolutionary complexity: Cockroach,Mango tree,Gorilla,Fish.

From the list given below,select the character which can be acquired but not inherited.

"Experiences of an individual during its lifetime cannot be passed on to its progeny and cannot direct evolution". Justify this statement giving an example.

$A$ cross was carried out between a pure-bred tall pea plant and a pure-bred dwarf pea plant,and $F_{1}$ progeny was obtained. Later,the $F_{1}$ progeny was selfed to obtain $F_{2}$ progeny. Answer the following questions:
$(a)$ What is the phenotype of the $F_{1}$ progeny and why?
$(b)$ Give the phenotypic ratio of the $F_{2}$ progeny.
$(c)$ Why is the $F_{2}$ progeny different from the $F_{1}$ progeny?