NEET 2019 Odisha · BiologyProkaryotePrevious Year Question

Which of the following nucleic acids is present in an organism having 70S ribosomes only ?

Answer: (B) Double stranded circular naked DNA. Answer: (B) Double stranded circular naked DNA Solution: An organism having only 70S ribosomes is a prokaryote, whose genetic material is a naked, double-stranded, circular DNA molecule not enveloped by a nuclear membrane and lacking histone packaging.

  1. A.Single stranded DNA with protein coat
  2. B.Double stranded circular naked DNA
  3. C.Double stranded DNA enclosed in nuclear membrane
  4. D.Double stranded circular DNA with histone proteins

Correct Answer

(B) Double stranded circular naked DNA

Solution & Explanation

Answer: (B) Double stranded circular naked DNA Solution: An organism having only 70S ribosomes is a prokaryote, whose genetic material is a naked, double-stranded, circular DNA molecule not enveloped by a nuclear membrane and lacking histone packaging. Options describing nuclear-membrane-enclosed DNA or DNA with histone proteins refer to eukaryotes (80S ribosomes), and single-stranded DNA with a protein coat describes a virus. Hence the prokaryote has double-stranded circular naked DNA. NCERT Reference: Ch 8, p.90, lines 6–9: "There is no well-defined nucleus. The genetic material is basically naked, not enveloped by a nuclear membrane. In addition to the genomic DNA (the single chromosome/circular DNA)"

🎯
43,000+ questions in हिंदी & English · one-tap toggle
Practice NEET 2019 Odisha Biology — free, with instant solutions
43,000+ NEET questions solved step-by-step, chapter-wise, in the MedicNEET app.
📚Practice all NEET Biology PYQs chapter-wise 💡Don't get it? Learn the Cell: The Unit of Life concepts