Question

Which group shares the most common characters with each other?
(a)Members of the same kingdom
(b)Members of the same genus
(c)Members of the same phylum
(d)Members of the same class
(e)Members of the same family

Answer 1

Hint: The group that shares the most common characters with each other is a taxonomic rank present just one level above the species according to the given option. For example in a botanical name, they constitute the first part of the name.

Complete answer:
The kingdom, division/phylum, class, order, family, genus, and species are the seven basic ranks of taxa in the descending order. As one progresses into the higher levels, the number of characters exchanged decreases. Therefore, members of the genus will exhibit the most common characters among the options given, which will continue to decrease as we pass to the kingdom.
A genus or genera in plural is a taxonomic rank used for the biological classification of living organisms. In the hierarchy of biological classification, the genus comes above the species and below the family. For each species within the genus, the name of the genus in binomial nomenclature forms the first part of the name of the binomial species.
Example: Two species within the genus Panthera are Panthera leo (lion) and Panthera onca (jaguar). Within the Felidae family, Panthera is a genus.

So, the correct answer is, ‘Members of the same genus’.

Note: A taxonomist is responsible for determining the composition of a genus. There is no strict formalization of the criteria for genus classification, so various authorities frequently create different classifications for genera. However, there are some common practices used, including the suggestion that these three conditions should be met by a newly established genus to be descriptively useful:
Monophyly: all offspring of an ancestor taxon are clustered together (i.e. both monophyly and validity as a separate lineage should be clearly shown by phylogenetic analysis).
Reasonable compactness: a genus should not be needlessly expanded.
Distinctness: with regard to evolutionary parameters, i.e. ecology, anatomy, or biogeography; DNA sequences are a result rather than a state of diverging evolutionary lines, except in cases where gene flow is specifically inhibited (one example is a postzygotic barrier).