AIIMS 2018 Zoology Bacterial Genetics MCQ Question

E. coli is a prokaryotic organism, meaning it has a single circular chromosome and is haploid, not diploid, which is why option A is incorrect. Option B is correct as E. coli is a normal inhabitant of the human intestine, playing a role in digestion. Option C is accurate because E. coli can undergo transformation, transduction, and conjugation, which are mechanisms of horizontal gene transfer. Lastly, option D is also correct since E. coli is widely used in recombinant DNA technology for cloning and protein expression due to its well-characterized genetics and rapid growth.