I've always felt like the biological definition of life isn't useful or meaningful when it comes to borderline replicators like viruses.

My biology is a bit rusty but I really have to wonder — are plants and animal cells even “alive”?

Take away the mitochondria and bacteria… can cells live on their own?

If no, then are we that all that different than this microbe?

Might even be sheer arrogance to think that we are the “host” (much like cats/dogs domesticating humans). Maybe we only exist to serve the mitochondria (:->