This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Biology Chapter 6 Molecular Basis Of Inheritance – Quiz 2 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 2 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. ASSERTION-The nitrogenous base of two chains of DNA are held together by hydrogen bondsReason-Both chains of DNA are antiparallel A) If both Assertion and Reason are true and reason is correct explanation of Assertion. B) If both Assertion and Reason are true but reason is not correct explanation of Assertion. C) Assertion is true reason is false. D) Both Assertion and Reason are false. Show Answer Correct Answer: B) If both Assertion and Reason are true but reason is not correct explanation of Assertion. 2. The association of histone H1 with a nucleosome indicates: A) DNA replication is occurring. B) The DNA is condensed into a Chromatin Fibre. C) The DNA double helix is exposed. D) Transcription is occurring. Show Answer Correct Answer: B) The DNA is condensed into a Chromatin Fibre. 3. One of two scientists who determined the double helix structure of DNA A) Oswald Avery. B) Erwin Chargaff. C) P.A. Levene. D) Francis Crick. Show Answer Correct Answer: D) Francis Crick. 4. Lac operon A) Is associated with anabolic process. B) Is a repressible operon. C) Has three structural genes. D) Is constituted by five structural genes. Show Answer Correct Answer: C) Has three structural genes. 5. What is the function of the enzyme topoisomerase in DNA replication? A) Elongating new DNA at a replication fork by adding nucleotides to the existing chain. B) Building RNA primers using the parental DNA strand as a template. C) Reattaching the hydrogen bonds between the base pairs in the double helix. D) Relieving strain in the DNA ahead of the replication fork caused by the untwisting of the double helix. Show Answer Correct Answer: D) Relieving strain in the DNA ahead of the replication fork caused by the untwisting of the double helix. 6. Which of these is correct fullform of BAC? A) Biotechnological application on chromososme. B) Bacterial artificial centre. C) Bacterial artificial chromosome. D) Biotechnolofical articicial chromosome. Show Answer Correct Answer: C) Bacterial artificial chromosome. 7. The effort to decipher the genetic code was led by ..... who was awarded Nobel Prize for his work A) Nirenberg. B) Lederberg. C) Watson. D) Crick. Show Answer Correct Answer: A) Nirenberg. 8. Which of the following is the function of RNA A) Adapter. B) Structural. C) Catalytic. D) All of the above. Show Answer Correct Answer: D) All of the above. 9. Select the correct match of enzyme with its related function. A) DNA polymerase-Synthesis of DNA strands. B) Helicase-Unwinding of DNA helix. C) Ligase-Joins together short DNA segments. D) All of these. Show Answer Correct Answer: D) All of these. 10. The model organism used by Meselson and Stahl to prove semi conservative DNA replication was A) Escherichia coli. B) Bacteriophage lambda. C) Streptococcus pneumoniae. D) Drosophila melanogaster. Show Answer Correct Answer: A) Escherichia coli. 11. The isotopes used by Hershey and Chase to prove that DNA is the genetic material R A) P32 and S35. B) P35 and S32. C) N15 and N15. D) N14 and N15. Show Answer Correct Answer: A) P32 and S35. 12. Nucleosome core is intimately associated with: A) 160 bp of DNA. B) 210 bp of DNA. C) 250 bp of DNA. D) 100 bp of DNA. Show Answer Correct Answer: A) 160 bp of DNA. 13. Which scientist(s) said that adenine and guanine equals thymine and cytosine? A) Franklin & Watkins. B) Chargaff. C) Griffith. D) Hershey & Chase. Show Answer Correct Answer: B) Chargaff. 14. The site of tRNA that binds to mRNA is A) Codon. B) Anticodon. C) 5' end. D) 3' end. Show Answer Correct Answer: B) Anticodon. 15. The enzyme peptidyl transferase of prokaryotes resides in A) 50S ribosome. B) 30S ribosome. C) 40S ribosome. D) 60S ribosome. Show Answer Correct Answer: A) 50S ribosome. 16. In prokaryotes, the region where DNA is organized is called: A) Nucleus. B) Nucleosome. C) Nucleoid. D) Chromatin. Show Answer Correct Answer: C) Nucleoid. 17. Which out of the following statements is incorrect? A) Genetic code is ambiguous. B) Genetic code is non-overlapping. C) Genetic code is universal. D) Genetic code is degenerate. Show Answer Correct Answer: A) Genetic code is ambiguous. 18. RNA that acts as ribozyme is A) MRNA. B) TRNA. C) RRNA. D) SnRNA. Show Answer Correct Answer: C) RRNA. 19. DNA is acidic due to A) Sugar. B) Purine. C) Phosphoric acid. D) Pyrimidine. Show Answer Correct Answer: C) Phosphoric acid. 20. Which non radioactive isotope was used by Meselson and Stahl in their experiments? A) $^{32 }$P. B) $^{35}$ S. C) $^{15}$ N. D) None. Show Answer Correct Answer: C) $^{15}$ N. 21. How did Meselson and Stahl distinguish the heavy DNA from the light DNA molecule? A) CsCl density gradient centrifugation. B) Buffer centrifugation. C) Spectroscopy. D) None of the above. Show Answer Correct Answer: A) CsCl density gradient centrifugation. 22. In prokaryotes, control of gene expression takes place at the level of A) Transcription. B) Translation. C) DNA replication. D) All of the above. Show Answer Correct Answer: A) Transcription. 23. Nucleotide excision repair A) Protein synthesis. B) Cell division. C) DNA repair mechanism that removes bulky DNA lesions. D) Photosynthesis. Show Answer Correct Answer: C) DNA repair mechanism that removes bulky DNA lesions. 24. What is the role of RNA polymerase in transcription? A) To repair DNA. B) To synthesize RNA. C) To replicate DNA. D) To unwind DNA. Show Answer Correct Answer: B) To synthesize RNA. 25. The enzyme that relieves the tension created ahead of the replication fork by unwinding DNA is: A) DNA ligase. B) DNA helicase. C) DNA topoisomerase. D) DNA primase. Show Answer Correct Answer: C) DNA topoisomerase. ← PreviousNext →Related QuizzesClass 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 1Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 3Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 4Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 5Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 6Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 7Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 8Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 9Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 10Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 11 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books