After which term and in what manner is the name of the author who described the species mentioned in biological nomenclature?

$A :$ Biological concept of species is based on reproductive isolation.
$R :$ Most accepted species concept was given by Linnaeus.

Explain the taxonomic categories (ranks) used in biological classification.

$A$ person who studies the origin,evolution,and variations in plants,as well as the classification of plants,is called a:

Cytotaxonomy is connected with

$I$ - Species,$II$ - Kingdom,$III$ - Class,$IV$ - Genus,$V$ - Family,$VI$ - Phylum,$VII$ - Order
Categories classified based on similar characteristics - $P$
Categories classified based on a group of characteristics - $Q$
Select the correct option for $P$ and $Q$.
$P\quad\quad\quad\quad\quad Q$