Answer:
the arrangement of animals and plants in taxonomic groups according to their observed similarities (including at least kingdom and phylum in animals, division in plants, and class, order, family, genus, and species).
<span>A key signature is most helpful in determining the "root and the scale used" a piece of music. Other purpose of key signature is that it tells you what key to play in order to avoid accidentals. Accidentals are symbols that modifies the pitch of the note, either making it into a sharp, a flat.</span>
It's all of the above. Hopefully that helps :)
