$A :$ Species is a genetically closed system.
$R :$ Because the reproductive isolation constitutes the most important boundary between different species.

What is the scientific name of the pea plant?

What is meant by botanical nomenclature?

Which of the following categories has more common characteristics than the species?

Which two taxa are mentioned in the scientific name of an organism?

Statement $S$: The family $Columbidae$ includes pigeons and doves,which consist of various genera and species.
Reason $R$: $A$ family is a category formed by a group of closely related genera.
$(a)$ Both $S$ and $R$ are true,and $R$ is the correct explanation of $S$.
$(b)$ Both $S$ and $R$ are true,but $R$ is not the correct explanation of $S$.
$(c)$ $S$ is true and $R$ is false.
$(d)$ $S$ is false and $R$ is true.
$(e)$ Both $S$ and $R$ are false.