Answer:
An organism is classified into seven levels in which the smallest level is species and the largest level is kingdom. The number of individuals, species and species richness increases when we move from species to kingdom and percentage of similarities decreases.
Members of species at lower levels are closely related to each other than members of a higher level. The level of classification from highest to lowest is Kingdom>Phylum>Class>Order>Family>Genus>Species.
So class is the higher level of classification than family so species in the same family are more closely related to each other than species in the same class.