Plasmids: Independent DNA Replication — NEET Biology
✅ Asked in NEET 2016Which of the following is not a feature of the plasmids? (NEET 2016 Phase 1)
Which of the following is not a feature of the plasmids? (NEET 2016 Phase 1)
Answer & NCERT explanation
Correct answer: B — Single-stranded
Plasmids are double-stranded, circular DNA molecules found in bacteria that replicate independently of chromosomal DNA. They can be transferred between bacterial cells through conjugation, transformation, or transduction. Single-stranded DNA is not a characteristic of plasmids - they exist as double-stranded structures. Options a, c, and d are all correct features of plasmids according to NCERT.
Read more NCERT concept on the PYQ
This discovery, in turn, led to a rich and rewarding conversation in Hawaii with a Stanford scientist named Stanley Cohen. Cohen had been studying small ringlets of DNA called plasmids and which float about freely in the cytoplasm of certain bacterial cells and replicate independently from the coding strand of DNA. Cohen had developed a method of removing these plasmids from the cell and then reinserting them in other cells. Combining this process with that of DNA splicing enabled Boyer and Cohen to recombine segments of DNA in desired configurations and insert the DNA in bacterial cells, which could then act as manufacturing plants for specific proteins. This breakthrough was the basis upon which the discipline of biotechnology was founded.
Plasmids are small, circular DNA molecules that exist independently in bacterial cytoplasm and replicate separately from the bacterial chromosome. NTA focuses on this independent replication property because it's fundamental to recombinant DNA technology. Students often confuse plasmids with chromosomal DNA or forget that plasmids replicate autonomously, which is why they're so useful as vectors in genetic engineering. The key point: plasmids are extrachromosomal DNA that can be extracted, modified, and reinserted into cells to carry foreign genes. This concept is crucial for understanding how bacteria become protein-manufacturing factories in biotechnology.
What does NCERT say about This discovery turn led?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.