No, it did come from a fungus (mushroom). There is no penicillin in snakes.
depends on the penicillin type and the bacterial cause, but if it is a susceptible organism and the type of penicillin is correct then the answer is yes. If you have been prescribed the penicillin by your doctor, then the answer is yes.
Depends on the snake
Deuteromycotes
It does
Without penicillin many wounded people would have died from infections. With it they did save many lived with the penicillin and sulfa drugs too. They also learned real fast that some people are fatally allergic to penicillin and they had to come up with a way to treat that problem.
penicillinase
There's no plant. Penicilin is extracted from penicilium, a fungus genus.
some medicines come from mold like penicillin
America
No. Penicillin comes originally from the penicillium mold (mould). The tetracyclines all come from the streptomyces mold (mould). Oxytetracycline is related to streptomycin. Allergy to it probably means allergy to streptomycin, but not to penicillin. And vice-versa.
the snake family
No.