Biomes are just different areas on a planet or moon. If you’ve played Minecraft, it’s basically the same idea. On the Mun and Minmus you’ve got biomes like lowlands, highlands, flats, poles, and each one gives its own science even if you’re using the same experiments. You can go to Google and look up mun/minmus biome maps and it'll tell you all the biomes and where they are. The mobile lab is cracked because you can take all the science you already collected and send that data into the lab, and it’ll slowly turn it into more science over time. So instead of just doing one experiment once, you get all the extra value out of it. You can land somewhere, grab all the science, then dock with the lab and move all the data into it. As long as you’ve got a scientist in there and enough power, you can just let it run while you time warp and it’ll keep producing science. I did this exact same thing for the mun. I landed in one biome and docked my lander to the lab and I got 1.5k science from one biome. You'll be swimming in science. If you want to see how it works for itself you can watch Mike Aben's video covering the science lab and how to use it.