All GRE Subject Test: Biology Resources
Example Question #7 : Evolution
A certain class of protein is found to exist in several different species. The amino acid sequence of this protein is compared between a large number of species. The greatest number of amino acid differences will be found between species of different __________.
The higher the taxonomic group, the less similar the members are. This is true for appearance, behavior, and genetics. The order of taxonomic groupings, from most general to most specific is: kingdom, phylum, class, order, family, genus, species.
Of the given answers, phyla are the highest taxonomic rank. Species of different phyla would show the greatest genetic difference. In contrast, genera are the lowest taxonomic rank of the given answers; species of the same genus would show the least genetic difference.