Diatoms aren’t “single celled plants” as per the writeup – that’s basically bad high school biology of the type that tries to claim that Paramecia are single celled animals. Not everything can be classified as plants or animals. Microbes are diverse, and can’t really be shoved into categories designed for macroscopic organisms. Not that this makes the idea of diatoms from space any more plausible, but as somebody who works on diatoms the misclassification is annoying.
