Question

Plasmid containing penicillinase gene is present in all strains of E. coli.

• A. True
• B. False

Answer 1

The correct option is B False

Penicillin is inactivated by the enzyme called penicillinase. The plasmid containing gene for penicillinase is found only in penicillin resistant strains of E. coli. There are other strains of E. coli as well, which are not antibiotic resistant or which contain plasmids with the gene conferring resistance to some other antibiotic like ampicillin or kanamycin.