Answer:
The correct answer is - diatom (protist)
Step-by-step explanation:
The characteristic described by the professor is most similar to the characteristic of aquatic protist - diatoms. Diatoms are the aquatic protist fall into the eukaryotic type of organisms.
These organisms are single-celled and can not swim on their own. They are a primary producer as they do not depends on others for their food and energy and synthesized themselves.