Definition of biome
Please don't generate and spread disinformation. Biomes are ecological organizations of living beings and mineral world. A huge crater on the Moon is not a biome - there is no life out there.
That's why we need to explain what biomes are in real life, and what do they represent in Kerbal Space Program, where they have a special meaning. Squad should've never named those regions biomes, but they did, so it's best to set things straight.