This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Biology Chapter 6 Molecular Basis Of Inheritance – Quiz 15 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 15 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. A mature mRNA consists of 900 bases without any stop codon in between. Calculate the number of amino acids coded by the mRNA during translation. A) 9000. B) 299. C) 300. D) 450. Show Answer Correct Answer: C) 300. 2. The transcription unit doesnot consist of A) Promoter. B) Structural gene. C) Origin of replication. D) Terminator. Show Answer Correct Answer: C) Origin of replication. 3. In lac operon, structural gene 'Z' synthesises A) Beta galactosidase. B) Galactosidase permase. C) Galactosidase transacetylase. D) None of these. Show Answer Correct Answer: A) Beta galactosidase. 4. Which of the following RNAs is not transcribed by RNA polymerase III? A) TRNA. B) MRNA. C) 5sRNA. D) SnRNA. Show Answer Correct Answer: B) MRNA. 5. The incorporation of an incorrect base into the DNA during replication ..... A) Will almost certainly lead to the death of the cell. B) Cannot be repaired, and a new mutation will invariably result. C) Can be repaired by the mismatch repair system. D) Is virtually impossible, as the accuracy of DNA polymerase is such that errors almost never occur. Show Answer Correct Answer: C) Can be repaired by the mismatch repair system. 6. The steps (rungs) of the DNA ladder are made up of ..... A) Phosphate groups. B) Sugars. C) Nitrogen bases. D) Amino acids. Show Answer Correct Answer: C) Nitrogen bases. 7. A stretch of which nucleotide in the DNA acts as the termination signal? A) Poly G. B) Poly C. C) Poly T. D) Poly A. Show Answer Correct Answer: D) Poly A. 8. Which of the following lists represents the order of increasingly higher levels of organization of chromatin? A) 30-nm chromatin fiber, nucleosome, looped domain. B) Nucleosome, 30-nm chromatin fiber, looped domain. C) Looped domain, 30-nm chromatin fiber, nucleosome. D) Nucleosome, looped domain, 30-nm chromatin fiber. Show Answer Correct Answer: B) Nucleosome, 30-nm chromatin fiber, looped domain. 9. The two strands in a DNA double helix are joined by A) Hydrogen bonds between sugars. B) Phosphodiester bonds between sugars. C) Hydrogen bond between bases. D) Phosphodiester bonds between bases. Show Answer Correct Answer: C) Hydrogen bond between bases. 10. The Hershey-Chase experiment A) Proved semiconservative replication is the mode for DNA replication. B) Used $^{32}$P to label protein. C) Used $^{35}$S to label DNA. D) Helped to prove DNA was the genetic molecule. Show Answer Correct Answer: D) Helped to prove DNA was the genetic molecule. 11. Which of these statement gives the correct chargaff's rule? A) A=T and G=C. B) G/C=A/T. C) A+G=T+C. D) ALL OF THE ABOVE. Show Answer Correct Answer: D) ALL OF THE ABOVE. 12. Okazaki is known for his contribution to the understanding of A) Transcription. B) Translation. C) DNA replication. D) Mutation. Show Answer Correct Answer: C) DNA replication. 13. What is meant by the description "antiparallel" regarding the strands that make up DNA? A) The twisting nature of DNA creates nonparallel strands. B) One strand is positively charged and the other is negatively charged. C) The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. D) Base pairings create unequal spacing between the two DNA strands. Show Answer Correct Answer: C) The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. 14. Which of these enzymes is responsible for breaking the hydrogen bonds which "unzips" the DNA molecule? A) Topoisomerase. B) Primase. C) Helicase. D) Zippase. Show Answer Correct Answer: C) Helicase. 15. The unwinding of DNA at the replication fork causes twisting and strain in the DNA ahead of the fork, which is relieved by an enzyme called ..... A) Primase. B) Ligase. C) Helicase. D) Topoisomerase. Show Answer Correct Answer: D) Topoisomerase. 16. DNA replication in eukaryotes differs from replication in bacteria because A) Synthesis of the new DNA strand is from 3' to 5' in eukaryotes and from 5' to 3' in bacteria. B) Synthesis of the new DNA strand is from 5' to 3' in eukaryotes and from 3' to 5' in bacteria. C) There are many replication forks in each eukaryotic chromosome and only one in bacterial DNA. D) Synthesis of the new DNA strand is from 5' to 3' in eukaryotes and is random in prokaryotes. Show Answer Correct Answer: C) There are many replication forks in each eukaryotic chromosome and only one in bacterial DNA. 17. Histones proteins are rich in amino acid residues A) Lysine and Histamine. B) Histamine and arginine. C) Lysine and arginine. D) None of these. Show Answer Correct Answer: C) Lysine and arginine. 18. Which nitrogen base does RNA have that DNA does not? A) Thymine. B) Adenine. C) Uracil. D) Cytosine. Show Answer Correct Answer: C) Uracil. 19. The first genetic material could be A) Protein. B) Cabohydrates. C) DNA. D) RNA. Show Answer Correct Answer: D) RNA. 20. DNA replication is A) Semi-conservative, continuous, unidirectional. B) Conservative, continuous. C) Semi-conservative, semi-discontinuous. D) Semi-continuous, conservative. Show Answer Correct Answer: C) Semi-conservative, semi-discontinuous. 21. Other than DNA polymerase, which are the enzymes involved in DNA synthesis? A) Topoisomerase. B) Helicase. C) RNA primase. D) All of these. Show Answer Correct Answer: D) All of these. 22. Which set of enzymes is involved in nucleotide excision repair? A) Ligase, nuclease, and primase. B) Nuclease, DNA polymerase, and ligase. C) DNA polymerase, helicase, primase. D) Nuclease, DNA polymerase, primase. Show Answer Correct Answer: B) Nuclease, DNA polymerase, and ligase. 23. Thymine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be cytosine? A) 42%. B) 31%. C) 16%. D) 8%. Show Answer Correct Answer: D) 8%. 24. Switching the position of promoter with terminator will cause all of the following variation, except the A) Change in nucleotide sequence of coding and template strands. B) Change in the polarity of coding and template strands. C) Change in the nucleotide sequence of transcribed RNA. D) Change in the sequence of amino acids in synthesized. Show Answer Correct Answer: B) Change in the polarity of coding and template strands. 25. Which mode of information transfer usually does not occur? A) DNA to DNA. B) DNA to RNA. C) DNA to protein. D) All occur in a working cell. Show Answer Correct Answer: C) DNA to protein. ← 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