What is the scientific name of potato?

Which one of the following statements is not true about the universal rules of binomial nomenclature?

When writing scientific names by hand,what is drawn under each word?

$I$ - 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 $Q$.
$P\quad\quad\quad\quad\quad Q$

Which scientific term is used for a convenient category for the study of organisms?

The term $Sapindales$ indicates: