The antibiotic called ampicillin was not effective against E.coli.
Answer: D
Explanation:
E.coli is normal microbial flora which is present in the gut of the mammals.
It is gram negative bacteria and very few strains of this bacteria causes harm.
Antibiotics are the chemical drugs which are used to treat the microbial infection either by killing the causative organism or by its growth inhibition.
Antibiotics such as neomycin, penicillin and erythromycin are usually used to treat E.coli infection.
Antibiotic such as Ampicillin is not used as the bacterium E.coli is highly resistant to it.
The correct answer is D. The theory of natural selection provided a better explanation of the processes that were being observed by the scientists.They observed that the related species birds found on one island were slightly different from that of the other, and certain portions earth, have the species, which were not found anywhere else.