This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Biology Chapter 6 Molecular Basis Of Inheritance – Quiz 23 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 23 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. In DNA, 10% of nitrogen bases are guanine.Then find out the percentage of Adenine. A) 90. B) 80. C) 40. D) 20. Show Answer Correct Answer: C) 40. 2. Which scientist proposed the Central Dogma of molecular biology? A) Frederick Griffith. B) Alfred Hershey. C) Francis Crick. D) Gregor Mendel. Show Answer Correct Answer: C) Francis Crick. 3. On reaching the terminator region of transcription unit A) Nascent RNA falls off. B) RNA polymerase falls off. C) Both nascent RNA and RNA Polymerase falls off. D) None of the above. Show Answer Correct Answer: C) Both nascent RNA and RNA Polymerase falls off. 4. In prokaryotic DNA replication, the lagging strand is synthesized: A) Continuously in 5' to 3' direction. B) Discontinuously in 3' to 5' direction. C) Discontinuously in 5' to 3' direction. D) Continuously in 3' to 5' direction. Show Answer Correct Answer: C) Discontinuously in 5' to 3' direction. 5. Functional unit of a gene is A) Exon. B) Cistron. C) Intron. D) Codon. Show Answer Correct Answer: B) Cistron. 6. During infection of E. coli cells by bacteriophage T$_{2}$ A) Proteins are the only phage components that actually enter the infected cell. B) Both proteins and nucleic acids enter the cell. C) Only protein from the infecting phage can also be detected in progeny phage. D) Only nucleic acids enter the cell. Show Answer Correct Answer: D) Only nucleic acids enter the cell. 7. Transcription starts non-specifically in the absence of A) Sigma factor. B) Rho factor. C) Core enzyme. D) DNA polymerase. Show Answer Correct Answer: A) Sigma factor. 8. The genetic code is said to be degenerate because: A) Some codons do not code for any amino acid. B) Some amino acids are coded by more than one codon. C) Some codons code for more than one amino acid. D) The code varies from one organism to another. Show Answer Correct Answer: B) Some amino acids are coded by more than one codon. 9. Identify the mismatch pair. A) Transforming principle-Frederick Griffith. B) Watson and crick-Double helical structure of DNA. C) Meselson and Stahl-Semiconservative replication of DNA. D) Jacob and Monod-X-ray diffraction of DNA. Show Answer Correct Answer: D) Jacob and Monod-X-ray diffraction of DNA. 10. How many pairs of nucleotides are present in one turn of DNA helix? A) 4. B) 8. C) 9. D) 10. Show Answer Correct Answer: D) 10. 11. Which of the following statements is the most appropriate for sickle cell anemia? A) It cannot be treated with iron supplements. B) It is a molecular disease. C) It confers resistance to acquiring malaria. D) All of the above. Show Answer Correct Answer: D) All of the above. 12. The elongation of the leading strand during DNA synthesis A) Progresses away from the replication fork. B) Depends on the action of DNA polymerase. C) Produces Okazaki fragments. D) Occurs in the 3' $\rightarrow$ 5' direction. Show Answer Correct Answer: B) Depends on the action of DNA polymerase. 13. Semi-discontinuous synthesis occurs in A) Prokaryotes. B) Eukaryotes. C) Both. D) Neither. Show Answer Correct Answer: C) Both. 14. For the translation to be initiated which of the following does not occur? a A) Binding of the large and small subunits of the ribosome. B) Addition of charged tRNA to the A site. C) Positioning of ribosome on 'GUG. D) Ribosome recruitment to the mRNA. Show Answer Correct Answer: C) Positioning of ribosome on 'GUG. 15. Methyl guanosine triphosphate is added to the 5' end of hnRNA in a process of: A) Splicing. B) Tailing. C) Capping. D) None of these. Show Answer Correct Answer: C) Capping. 16. How many nucleotide bases are present in human genome? A) 3164.7million. B) 1364.7million. C) 3146.7million. D) 3064.7million. Show Answer Correct Answer: A) 3164.7million. 17. Which of the following statements correctly describes the difference between ATP and the nucleotides used during DNA synthesis? A) The nucleotides have the sugar deoxyribose; ATP has the sugar ribose. B) ATP contains three high-energy bonds; the nucleotides have two. C) The nucleotides have two phosphate groups; ATP has three phosphate groups. D) ATP is found only in human cells; the nucleotides are found in all animal and plant cells. Show Answer Correct Answer: A) The nucleotides have the sugar deoxyribose; ATP has the sugar ribose. 18. Consider the following statements.Statement I:Two nucleotides are linked through 3'-5' phosphodiester linkage to form a dinucleotide.Statement II:An adenosine nucleoside consists of pentose sugar, phosphate group and nitrogenous base adenine. A) Both the statements are true. B) Both the statements are false. C) Only statement II is true. D) Only statement I is true. Show Answer Correct Answer: D) Only statement I is true. 19. If the sequence of bases in the DNA is ATTCGATG (POLARITY IS 5' TO 3'), THEN THE SEQUENCES OF BASES IN THE TRANSCRIPT WILL BE A) ATTCGAAG. B) TAAGCTAC. C) AUUCGAUG. D) NONE OF THE ABOVE. Show Answer Correct Answer: C) AUUCGAUG. 20. Transcription unit in DNA is A) Promoter. B) Structural gene. C) Terminator. D) All. Show Answer Correct Answer: D) All. 21. Which of the following is most likely to have a small protein called ubiquitin attached to it? A) A cell surface protein that requires transport from the ER. B) An mRNA that has been translated. C) A promoter that usually acts in S phase, now that the cell is in G2. D) A regulatory protein that requires sugar residues to be attached. Show Answer Correct Answer: B) An mRNA that has been translated. 22. Which of the following ensure stable binding of RNA polymerase at the promoter site? A) DNA photolyase. B) Sigma factor. C) DNA glycosylase. D) RecA. Show Answer Correct Answer: B) Sigma factor. 23. Semi-conservative replication of DNA refers to the idea that A) DNA molecules need to unwind before duplication begins. B) Each new DNA molecule contains two new single RNA strands. C) The two strands of DNA molecules run in opposite directions. D) Each half of the original DNA molecule is joined with a new complementary DNA strand. Show Answer Correct Answer: D) Each half of the original DNA molecule is joined with a new complementary DNA strand. 24. DNA polymerase adds nucleotides to the ..... of the leading strands, and to the ..... of the lagging strands (Okazaki fragments). A) 3' end 3' end. B) 5' end 5' end. C) 3' end 5' end. D) 5' end 3' end. Show Answer Correct Answer: A) 3' end 3' end. 25. What enzyme is responsible for laying down the RNA primers during DNA Replication? A) Helicase. B) RNA Primase. C) Ligase. D) There are no RNA primers during DNA Replication. Show Answer Correct Answer: B) RNA Primase. ← 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