chemical, pathogen, enzyme, hormone
What different categories can plankton be placed into?
Both, it can also be placed under "rocks."
The term, phylum, is a term used for classification categories into which organisms are placed. A phylum is a subcategory of a species.
Topical antibiotics are then placed in the ear.
I think it should. Overuse of antibiotics results in bacterium becoming resistant to said antibiotics.
Doctor's prescribe a course of antibiotics - so the full course of antibiotics should be taken.