Answer:
There are a number of mechanisms through which a bacterial cell might become resistant to a specific antibody.
- Some bacteria might posses a cell membrane which wouldn't allow the transfer of antibiotics into the cell of the bacteria. Some bacterial cells might not have the target sites on which the antibiotics attack. A bacterial cell that would be non-resistant wouldn't block the entry of the drug or it might not lack the site where the drug has to function.
- Some resistant bacteria might produce enzymes that would inactivate the activity of the antibiotics. This enzyme machinery would lack in a non-resistant strain. The resistant bacteria might have undergone mutations over a period of time to evolve a machinery for antibiotic resistance.