B, very interesting. I once did an extra credit type thing whilst attending Lascaux high. I persuaded the Biology instructor to do an experiment. He ordered everything I needed.
Bare with me here it was long ago and I can not spell.
Petrie dishes , agar, some kind of cocci bacillus) pnumo or strepto)?
auromycine, streptomycin and I think Terramycin, on little disks or wafers.
I set all the dishes up and contaminated each of them with the bacillus, and incubated until I had flourishing life. Then I divided the dishes into several groups, introduced the disks and developed strains that were immune to the antibiotics. Then I put a strain that was immune to one anti b, into another dish with another anti b, and then took that strain and introduced that strain and introduced that to the third anti b. What I ended up with was, through the stereo microscope was a flattish curve sided lozenge shaped, divided into perhaps 5-7 segments cell or colony. I thought at the time the outside was dead membrane or cells that protected the more alive/ virulent bacillus inside. This took maybe 4-6 weeks and the instructor never followed any of this until I requested his opinion and showed him, with great pride, all my notes. He reads, paled to an ashen grey and says" what in H... Is wrong with you Germans and your fascination with germ warfare." We spent the entire night destroying, autoclaving and sanitizing. He made me promise never to talk about this at school for both our good. Mad Asper at work, I was 14 now 67. First time I told the story.