Public humiliation by a seventh grade science teacher
Is your avatar an accurate depiction of your reaction to this public humiliation?

7th grade science teachers don't know everything. I had one who told the class that glass is actually a really slow moving liquid and not actually a solid. It wasn't until some time later that I found out that was a myth and was false, but that's what he told the class... so teachers don't know everything.
As for the viruses, I think its debatable whether they count as a life form or not. There are some who will say they are the most simple and primitive form of life, and then there are those who disagree on them being alive at all. Who is right? There is no right or wrong answer there. It just depends on who ask because its very subjective. So I think both you and your teacher were right, and he shouldn't have publicly humiliated you.
But to get this back on topic, I don't think real world arguments should apply in video games. Regardless of what viruses are or aren't in real life, in Dr. Mario they have faces and look like animated creatures... it seems like just the sort of thing PETA would want to throw a fit over.