Answer to Question #153769 in Genetics for Kabir

Question

Suppose a plasmid named ABC initially did not contain any antibiotic resistant gene. Suddenly you found this plasmid having penicillin and tetracycline resistant gene. What do you think how is it occurred? 

Answer 1

Antibiotic resistance arises spontaneously through random mutation by natural selection. Bacteria can then transfer the genetic information in a horizontal way (between individuals) through plasmid exchange once such a gene is produced.