You live in a city in Florida on the Gulf of Mexico and are trying to figure out why the water at the beaches turned bright green for several months during the summer. You discover the green comes from a photosynthetic organism that grew at great numbers due to fertilizer spill in a nearby river. You have isolated the organism and are now testing its DNA. You extract all the DNA from your sample and find that there are three distinct kinds of DNA. Which of the following organisms could have been responsible for the bloom: fungus, bacteria, or protist? How do you know?