Long-term use, abuse and overuse of antibiotics will lead to the increase of drug-resistant strains, which is the choice of antibiotic resistance to bacteria.

Long-term use, abuse and overuse of antibiotics will lead to the increase of drug-resistant strains. Is it the choice of bacterial resistance to antibiotics or the bacterial mutation induced by antibiotics? Someone designed the following experiment (as shown below):

The main steps are as follows: (1) Inoculate bacteria on normal culture medium A to make the bacteria multiply in large quantities, and the culture medium is densely covered with colonies; (2) pressing the surface of the sterilized flannel with the same inner diameter as the culture dish on the bacterial culture medium A, so that the surface of the flannel is stained with colonies; ③ Press the surface of flannel on a series of medium B containing penicillin, and be careful not to rotate the surface of flannel to ensure that bacteria are in the position corresponding to medium A; (4) Find the same colony from A and inoculate it on culture medium C containing penicillin. Therefore, all strains can form colonies normally.

Please answer:

(1) The colony in bacterial culture is called _ _ _ _ _ _ _ _ _ in ecology.

(2) The experimental results show that bacterial resistance occurs before or after exposure to penicillin _ _ _ _ _ _ _ _ _; Penicillin has _ _ _ _ _ _ effect on bacteria; The resistance of bacteria in culture medium A to penicillin is _ _ _ _ _ _ _ _ _.

(3) The resistance of bacteria comes from _ _ _ _ _ _ _ _.

(4) Try to explain the above process with modern biological evolution theory: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

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