In science, the practice of classifying organisms is called taxonomy (Taxis means arrangement and nomos mean method). The modern taxonomic system was developed by the Swedish botanist Carolus Linnaeus (1707-1778). ... To distinguish different levels of similarity, each classifying group, called taxon
Catalase<span> is a common enzyme </span>found<span> in nearly all </span>living organisms<span> exposed to oxygen</span>
I don't know if they might be tricking you or something but I believe the only level of organization found in the human heart is: organ.
HOPE IT HELPED! :)
