This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Biology > Class 12 Biology Chapter 6 Molecular Basis Of Inheritance – Quiz 10 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 10 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. 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. 2. 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. 3. 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. 4. Transcription unit in DNA is A) Promoter. B) Structural gene. C) Terminator. D) All. Show Answer Correct Answer: D) All. 5. 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. 6. Which of the following ensure stable binding of RNA polymerase at the promoter site? A) RecA. B) Sigma factor. C) DNA glycosylase. D) DNA photolyase. Show Answer Correct Answer: B) Sigma factor. 7. 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. 8. DNA polymerase adds nucleotides to the ..... of the leading strands, and to the ..... of the lagging strands (Okazaki fragments). A) 5' end 5' end. B) 3' end 5' end. C) 5' end 3' end. D) 3' end 3' end. Show Answer Correct Answer: D) 3' end 3' end. 9. What enzyme is responsible for laying down the RNA primers during DNA Replication? A) Helicase. B) RNA Primase. C) There are no RNA primers during DNA Replication. D) Ligase. Show Answer Correct Answer: B) RNA Primase. 10. Splicing is one of the steps of post-transcriptional modifications which occurs in A) Cytoplasm. B) Nucleus. C) ER. D) Ribosomes. Show Answer Correct Answer: B) Nucleus. 11. Heterochromatin is A) Active. B) Light-stained. C) Compact. D) Gene-rich. Show Answer Correct Answer: C) Compact. 12. Information used by Watson and Crick to determine the structure of DNA included A) Electron micrographs of individual DNA molecules. B) Light micrographs of bacteriophage particles. C) Nuclear magnetic resonance analysis of DNA. D) X-ray crystallography of double-stranded DNA. Show Answer Correct Answer: D) X-ray crystallography of double-stranded DNA. 13. If a person suffered from a disorder where their DNA fragments were unable to fill in the missing slots in between the fragments of the lagging strand, they would most likely have a disorder that affected which enzyme? A) DNA polyermase. B) DNA Helicase. C) RNA PolymeraseTagsDNA replication enzymes. D) DNA Ligase. Show Answer Correct Answer: D) DNA Ligase. 14. In prokaryotes, the initiation factors (IF-1, IF-2, and IF-3) are involved in the initiation of protein synthesis. Which of the following factors facilitates the initiation codon? A) IF-1. B) IF-2. C) IF-3. D) All of the above. Show Answer Correct Answer: B) IF-2. 15. Which scientist experimentally proved that DNA is the sole genetic material in bacteriophage? A) Jacob and Monod. B) Beadle and Tautum. C) Messelson and Stahl. D) Hershey and Chase. Show Answer Correct Answer: D) Hershey and Chase. 16. What is meant by the description "antiparallel" regarding the two strands that make up the DNA double helix? A) The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. B) One strand contains only purines and the other contains only pyrimidines. C) The double helix structure of DNA creates nonparallel strands. D) Base pairings create unequal spacing between the two DNA strands. Show Answer Correct Answer: A) The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. 17. The removal of the RNA primer and addition of DNA nucleotides to the 3' end of Okazaki fragments in its place is carried out by ..... A) DNA polymerase I. B) Primase. C) Nuclease. D) Ligase. Show Answer Correct Answer: A) DNA polymerase I. 18. The central dogma reverse flow occurs in A) Animals. B) Algae. C) Viruses. D) Bacteria. Show Answer Correct Answer: C) Viruses. 19. The diameter of DNA helix is A) 10nm. B) 2nm. C) 21A. D) 1nm. Show Answer Correct Answer: B) 2nm. 20. What makes the exact copying of DNA molecules possible? A) The double helix shape. B) Sugar-phosphate backbone. C) Base pairing. D) Hydrogen bonding between nucleotides. Show Answer Correct Answer: C) Base pairing. 21. During DNA replication, Okazaki fragments are used to elongate: A) The lagging strand towards replication fork. B) The leading strand away from replication fork. C) The lagging strand away from the replication fork. D) The leading strand towards replication fork. Show Answer Correct Answer: C) The lagging strand away from the replication fork. 22. Name the plant used by Taylor & Co in their experiment A) Oryza sativa. B) Triticum vulgare. C) Vincia faba. D) None of the above. Show Answer Correct Answer: C) Vincia faba. 23. What scientist(s) used bacteriophages to show that DNA is what carries our genetic material? A) Chargraff. B) Hershey and Chase. C) Rosalind Franklin. D) Watson and Crick. Show Answer Correct Answer: B) Hershey and Chase. 24. The force that holds DNA together in a double helix is A) The force of the twist. B) Hydrogen bonds. C) Covalent bonds. D) Ionic bonds or ionic interactions. Show Answer Correct Answer: B) Hydrogen bonds. 25. Enzymes called ..... add complementary nucleotides, floating inside the nucleus. A) DNA polymerase. B) DNA synthetase. C) Lipoprotein. D) None of these. Show Answer Correct Answer: A) DNA polymerase. 26. If an organism's DNA contains 22% Thymine, what percentage Cytosine will it have? A) 25%. B) 78%. C) 22%. D) 28%. Show Answer Correct Answer: D) 28%. 27. Who first identified the biochemical nature of gene? A) Freiderich Griffith. B) Hershy and Chase. C) Averoy and Mac Leod. D) Measelson and Stahl. Show Answer Correct Answer: C) Averoy and Mac Leod. 28. Generally only one strand of DNA is transcribed. This strand is called A) "A" strand. B) "B" strand. C) Sense strand. D) Template strand. Show Answer Correct Answer: D) Template strand. 29. Read the following statementsStatement I:5-methyl uracil is present in RNA molecule.Statement II:The packaging of chromatin at higher level requires additional set of proteins that collectively are referred to as histone proteins. A) Only statement I is correct. B) Only statement II is correct. C) Both statements are correct. D) Both statements are incorrect. Show Answer Correct Answer: D) Both statements are incorrect. 30. Lactose Operon is a set of lactose metabolizing gene that is co-coordinately expressed and regulated. The following is not the gene of lactose operon: A) LacY. B) LacZ. C) LacA. D) LacX. Show Answer Correct Answer: D) LacX. 31. Why were fragments like those now called Okazaki fragments expected before they were discovered? A) DNA replicates in the 5' to 3' direction. B) The replication fork moves forward along a double-stranded DNA molecule. C) DNA replicates in the 3' to 5' direction on the lagging strand. D) RNA primase places short RNA primer sequences along the DNA molecule. Show Answer Correct Answer: B) The replication fork moves forward along a double-stranded DNA molecule. 32. In a double-stranded DNA molecule, if one strand has the sequence 5'-ATGCGT-3', the complementary strand will have: A) 3'-TACGCA-5'. B) 5'-ACGCAT-3'. C) 5'-TACGCA-3'. D) 3'-ACGCAT-5'. Show Answer Correct Answer: A) 3'-TACGCA-5'. 33. E. coli cells grown on $^{15}N$ $^{14}N$ A) One high-density and one intermediate-density band. B) One high-density and one low-density band. C) One low-density and one intermediate-density band. D) One intermediate-density band. Show Answer Correct Answer: C) One low-density and one intermediate-density band. 34. Who proposed the semiconservative nature of DNA A) Fredrick griffith. B) Francis crick. C) Darwin. D) Meselson and stahl. Show Answer Correct Answer: B) Francis crick. 35. Which of the following vectors are widely used in HGP? A) Plasmid and cosmid. B) Lamba phage and M13 vectors. C) Phagemid and shuttle vectors. D) BAC and YAC. Show Answer Correct Answer: D) BAC and YAC. 36. The terms cistron, recon and muton were proposed by A) Benzer. B) Lederberg. C) Johansen. D) Morgan. Show Answer Correct Answer: A) Benzer. 37. Reverse transcription was discovered by A) Beadle and Tatum. B) Watson and Crick. C) Khorana. D) Temin and Baltimore. Show Answer Correct Answer: D) Temin and Baltimore. 38. Gyrase helps in relaxing supercoils of DNA. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 39. The ribosome has three binding sites (A, P, E) for tRNA molecules. Which of the following is NOT the correct statement regarding these sites? A) The A site binds to an incoming aminoacyl-tRNA. B) The P site codon is occupied by peptidyl-tRNA (an amino acid containing tRNA). C) The E site is occupied by empty t-RNA as it is exiting the ribosome. D) None of the Above. Show Answer Correct Answer: D) None of the Above. 40. A frameshift mutation is caused by: A) Insertion or deletion of three bases. B) Duplication of a chromosome segment. C) Insertion or deletion of one or two bases. D) Substitution of one base for another. Show Answer Correct Answer: C) Insertion or deletion of one or two bases. 41. If the total amount of adenine and thymine in a double-stranded DNA is 45%, the amount of guanine in this DNA will be A) 27.5%. B) 45%. C) 55%. D) 22.5%. Show Answer Correct Answer: A) 27.5%. 42. Which of the following be named for DNA produced from RNA A) C-DNA. B) Z-DNA. C) A-DNA. D) B-DNA. Show Answer Correct Answer: A) C-DNA. 43. The begining of understanding genetic transformation in bacteria was made by: A) Frederich Griffth. B) Hershy and Chase. C) Watson and Crick. D) T .H Morgan. Show Answer Correct Answer: A) Frederich Griffth. 44. Select the correct cap to complete:The 5' end of mRNA is capped with ..... A) 5' phosphate only. B) Poly-A tail. C) Methyl guanosine (m7G cap). D) 3' cap. Show Answer Correct Answer: C) Methyl guanosine (m7G cap). 45. The biochemical nature of transforming principle was defined by A) Griffith. B) Avery, Macleod, McCarty. C) Watson and Crick. D) Taylor. Show Answer Correct Answer: B) Avery, Macleod, McCarty. 46. 5' end of DNA and RNA contains which chemical group A) OH. B) PO4. C) SO4. D) None of these. Show Answer Correct Answer: B) PO4. 47. Peptide bond formation is catalyzed by A) DNA. B) TRNA. C) RRNA (23S). D) MRNA. Show Answer Correct Answer: C) RRNA (23S). 48. During translation, the ..... site within the ribosome holds the growing amino acids chain while the ..... site holds the next amino acid to be added to the chain. A) P, A. B) A, B. C) B, A. D) A, P. Show Answer Correct Answer: A) P, A. 49. What two scientists are given credit for discovering the structure of DNA? A) Hershey and Chase. B) Watson and Crick. C) McCarty and MacLeod. D) Meselson and StahlTagsDNA replication experiments. Show Answer Correct Answer: B) Watson and Crick. 50. Which molecule brings amino acids to the ribosomes for assembling into proteins? A) DNA. B) MRNA. C) RRNA. D) TRNA. Show Answer Correct Answer: D) TRNA. 51. Select the correct term to complete: ..... proposed the operon concept. A) Jacob and Monod. B) Watson and Crick. C) Beadle and Tatum. D) Meselson and Stahl. Show Answer Correct Answer: A) Jacob and Monod. 52. Who amongst the following had no contribution in the development of the double helix model for the structure of DNA. A) Rosalind Franklin. B) Maurice Wilkins. C) Erwin Chargaff. D) Measelson and Stahl. Show Answer Correct Answer: D) Measelson and Stahl. 53. Which base always pairs with guanine? A) Uracil. B) Cytosine. C) Adenine. D) Thymine. Show Answer Correct Answer: B) Cytosine. 54. Why does a new DNA strand elongate only in the 5' to 3' direction during DNA replication? A) The polarity of the DNA molecule prevents addition of nucleotides at the 3' end. B) Replication must progress toward the replication fork. C) DNA polymerase begins adding nucleotides at the 5' end of the template. D) DNA polymerase can add nucleotides only to the free 3' end. Show Answer Correct Answer: D) DNA polymerase can add nucleotides only to the free 3' end. 55. Meselson and Stahl used ..... to label DNA. A) 3H. B) 15N. C) 32P. D) 14C. Show Answer Correct Answer: B) 15N. 56. The new DNA strand formed after DNA replication is an exact copy of its parent strand A) True. B) FalseTagsMeselson/Stahl experiment. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 57. Which of the following chromosomes has the largest genes A) 11. B) 24. C) 21. D) 1. Show Answer Correct Answer: D) 1. 58. Okazaki Fragments A) Small sections of DNA formed during discontinuous replication. B) Replication is continuous on strand. C) Replication is discontinuous on strand. D) None of the above. Show Answer Correct Answer: A) Small sections of DNA formed during discontinuous replication. 59. Introns are part of DNA which A) Code for protein synthesis. B) Help in joining pieces of DNA. C) Do not code for protein synthesis. D) Initiate transcription. Show Answer Correct Answer: C) Do not code for protein synthesis. 60. If bacterial double stranded DNA with $^{15}$N undergoes replication twice in a normal medium of nitrogen ($^{14}$N), then which of the following results A) Half contain $^{15}$N in DNA. B) All four contain $^{15}$N in DNA. C) None contains $^{15}$N in DNA. D) 1/4$^{th }$contains $^{15}$N in DNA. Show Answer Correct Answer: A) Half contain $^{15}$N in DNA. ← PreviousNext →Related QuizzesScience QuizzesClass 12 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 8 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books