This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Biology Chapter 6 Molecular Basis Of Inheritance – Quiz 12 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 12 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. RNA polymerase I, transcribes all the given types of RNA, except A) 5.8 s rRNA. B) 18 s rRNA. C) 5 s rRNA. D) 28 s rRNA. Show Answer Correct Answer: C) 5 s rRNA. 2. The switching 'on' and 'off ' of the lac operon in prokaryotes is regulated by A) Glucose. B) Galactose. C) Lactose. D) Fructose. Show Answer Correct Answer: C) Lactose. 3. Which of the following describes the direction the template strand is read? A) 5' to 3'. B) 3' to 5'. C) N terminus to C terminus. D) C terminus to N terminus. Show Answer Correct Answer: B) 3' to 5'. 4. Name the chemical used by Taylor and co workers to show semi-conservative method of replication A) Thymidine. B) Iron. C) Copper. D) Titanium. Show Answer Correct Answer: A) Thymidine. 5. How many types of DNA dependent RNA polymerase catalysis transcription of all RNA in prokaryotes? A) One. B) Two. C) Six. D) Multiple. Show Answer Correct Answer: A) One. 6. Adenine & guanine A) Are heterocyclic compounds. B) Does not contain pyrimidine ring. C) Have 9-membered single ring structure. D) Are pyrimidine nitrogenous bases. Show Answer Correct Answer: A) Are heterocyclic compounds. 7. DNA duplication occurs at A) Meiosis-II. B) Mitotic interphase. C) Mitosis only. D) Meiosis and mitosis both. Show Answer Correct Answer: D) Meiosis and mitosis both. 8. What gives DNA its stability A) Hydrogen bond. B) Double stranded str. C) Thymine, deoxyribose. D) All of these. Show Answer Correct Answer: D) All of these. 9. The hypothesis that RNA was the first genetic material is supported by RNA's ability to: A) Form hydrogen bonds. B) Act as both genetic material and enzyme. C) Pair with DNA. D) Undergo transcription. Show Answer Correct Answer: B) Act as both genetic material and enzyme. 10. The nitrogenous bases (and the two strands of the DNA double helix) are held together by A) Weak van der Waals forces. B) Covalent bonds. C) Hydrogen bonds. D) A and b. Show Answer Correct Answer: C) Hydrogen bonds. 11. What is the function of lactose in lac operon A) To bind with repressor protein. B) To initiate the transcription. C) To synthesize structural genes. D) All of the above. Show Answer Correct Answer: A) To bind with repressor protein. 12. The structure of DNA is characterized by a A) Right-or-left-handed double helix and antiparallel strands. B) Right-handed double helix and antiparallel strands. C) Right-handed single helix. D) Right-handed single helix and parallel strands. Show Answer Correct Answer: B) Right-handed double helix and antiparallel strands. 13. Which mRNA codon will match with the DNA strand ATG? A) UAC. B) ATG. C) TAC. D) CGT. Show Answer Correct Answer: A) UAC. 14. Which experiment provided unequivocal proof that DNA is the genetic material? A) Griffith's transformation experiment. B) Avery, MacLeod and McCarty's experiment. C) Hershey-Chase experiment. D) Meselson-Stahl experiment. Show Answer Correct Answer: C) Hershey-Chase experiment. 15. Muscle cells differ from nerve cells mainly because they A) Have unique ribosomes. B) Use different genetic codes. C) Contain different genes. D) Express different genes. Show Answer Correct Answer: D) Express different genes. 16. DNA is a polymer of nucleotides which are linked to each other by 3'-5' phosphodiester bond. To prevent polymerisation of nucleotides, which of the following modification would you choose A) Replace purine with pyrimidine. B) Remove 3' OH group in deoxyribose. C) Remove 2'OH group with some other group in deoxyribose. D) Both B and C. Show Answer Correct Answer: B) Remove 3' OH group in deoxyribose. 17. What are the roles of replication and replication forks in DNA replication? A) Replication is the process of copying DNA, and replication forks are the areas where the DNA double helix is unwound to allow replication. B) Replication forks are the enzymes that synthesize new DNA strands, and replication is the process of unwinding the DNA. C) All the above. D) None of the above. Show Answer Correct Answer: A) Replication is the process of copying DNA, and replication forks are the areas where the DNA double helix is unwound to allow replication. 18. In eukaryotes, in order to initiate transcription A) RNA strand must be present. B) RNA polymerase must be present. C) Core promoter sequence must be present. D) None of these. Show Answer Correct Answer: C) Core promoter sequence must be present. 19. AGGTATCGCAT is a sequence from the coding strand of a gene. What will be the corresponding sequence of the transcribed mRNA? A) UGGTUTCGCAT. B) AGGUAUCGCAU. C) UCCAUAGCGUA. D) ACCUAUGCGAU. Show Answer Correct Answer: B) AGGUAUCGCAU. 20. Which eukaryotic RNA polymerase primarily transcribes mRNA-coding genes? A) RNA polymerase I. B) RNA polymerase II. C) RNA polymerase III. D) Mitochondrial RNA polymerase. Show Answer Correct Answer: B) RNA polymerase II. 21. In a DNA molecule, if adenine comprises 15% of the bases, what percentage will be guanine? A) 15%. B) 30%. C) 35%. D) 70%. Show Answer Correct Answer: C) 35%. 22. In the lactose operon system in E. coli, the repressor is- A) A product of a structural gene locus. B) Bound to the promoter sequence. C) Lactose. D) A protein. Show Answer Correct Answer: D) A protein. 23. The lac operon consists of? A) 3 regulatory genes and 3 structural genes. B) 2 regulatory genes and 2 structural genes. C) One regulatory gene and 3 structural genes. D) 4 regulatory genes only. Show Answer Correct Answer: C) One regulatory gene and 3 structural genes. 24. Sickle-cell anemia is due to A) Deletion. B) Substitution. C) Inversion. D) Addition. Show Answer Correct Answer: B) Substitution. 25. Anti-codons are found on which molecule? A) MRNA. B) TRNA. C) RRNA. D) DNA. Show Answer Correct Answer: B) TRNA. ← PreviousNext →Related QuizzesClass 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 1Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 2Class 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 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books