What is the taxonomic category formed by a group of related genera?

Which option provides the correct answers to the following questions regarding a species?
$(i)$ What kind of offspring is a species capable of producing?
$(ii)$ What kind of individuals are included in a species?
$(iii)$ In some cases,what name is written after the species name?
$(iv)$ What is the species name of sunflower?

What is the scientific name of potato?

Attempt giving a clear definition of the term species.

Karyotaxonomy is the modern branch of classification which is based on

Define the term: Genus.