Which of the following statements is correct regarding a species?

$X$ being a higher category is the assemblage of families which exhibit a few $Y$ characters. The $Z$ characters are less in number as compared to different genera included in a family. Identify $X$, $Y$, and $Z$.

The scientific naming of animals is based on the principles and criteria provided by which organization?

The science of naming plants is known as

Match the following columns:

Column-$I$	Column-$II$
$P$. Chemotaxonomy	$I$. Uses computers to easily process data based on all observable characteristics.
$Q$. Cytotaxonomy	$II$. Based on evolutionary relationships.
$R$. Numerical taxonomy	$III$. Uses chemical constituents of plants.
$S$. Phylogenetic taxonomy	$IV$. Uses information like chromosome number, structure, and behavior.

What is the term given to the groups of organisms arranged at different levels of classification?