Dorothy works as a medicinal chemist in a pharmaceutical company. what could one of her assignments be

I don't know if you have any options, but some of her assignments would definitely be the creation of drugs. Since she is a medicinal chemist, it means that she has the necessary knowledge to make medicine, which can later be sold in a pharmacy. 

Fungi is were it belongs

You should never redesign your experiment. try and see what in your experiment you made a mistake on or try and test your experimemt with somebody else. see if they get the right results.