metabolic pathways!!!!!!!!!!!!!!!!!!!!!!!!!!!
I would say option A, when a drug kills most of the bacteria the ones left to breed are those that have a natural resistance to the drug.
B) sunlight
Sunlight supports life by providing food and warmth which is needed for the population of practically anything on earth to survive
A particle with only 9 protons and no electrons would be an ion, because one proton contains a +1 charge and one electron contains a -1 charge while neutrons have no charge. This particle, without electrons would then have an ionic charge of +9.
Surface to volume i think
