This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Biology > Class 12 Biology Chapter 6 Molecular Basis Of Inheritance – Quiz 17 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Biology Chapter 6 Molecular Basis Of Inheritance Quiz 17 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which of the following rRNAs is not transcribed by RNA polymerase I? A) 28s. B) 5s. C) 18s. D) 5.8s. Show Answer Correct Answer: B) 5s. 2. Genetic code consists of-*******A. Adenine and guanine*******B. Riboflavin and ATP*******C. Cytosine and Guanine*******D. Cytosine and Uracil A) A, C, D. B) A, D. C) B, C, D. D) None of the above. Show Answer Correct Answer: B) A, D. 3. The functional unit of inheritance is A) Gene. B) Allele. C) Promoter. D) Introns. Show Answer Correct Answer: A) Gene. 4. What is the function of reverse transcriptase in retroviruses? A) It uses viral RNA as a template for DNA synthesis. B) It hydrolyzes the host cell's DNA. C) It translates viral RNA into proteins. D) It converts host cell RNA into viral DNA. Show Answer Correct Answer: A) It uses viral RNA as a template for DNA synthesis. 5. Experiment called the unequivocal proof of DNA being genetic material was performed by A) Marshall Nirenberg and Hargobind Khorana. B) Avery, Macleod, and McCarty. C) Alfred Hershey and Martha Chase. D) Francis Crick and James Watson. Show Answer Correct Answer: C) Alfred Hershey and Martha Chase. 6. Which of the following gene encodes for repressor protein of lac operon A) LacY. B) LacI. C) LacA. D) LacZ. Show Answer Correct Answer: B) LacI. 7. 5' end of a polynucleotide chain contains A) Hydroxyl group. B) Ethyl group. C) Carboxyl group. D) Phosphate group. Show Answer Correct Answer: D) Phosphate group. 8. Which of the following cannot act as inducer? A) Glucose. B) Lactose. C) Galactos. D) Both (a) and (c). Show Answer Correct Answer: D) Both (a) and (c). 9. DNA is a better genetic material than RNA because, DNA lacks A) 5-methyl uracil in place of uracil. B) Ability to generate its replica. C) Ability to slowly mutate. D) 2'OH group in the sugar of its nucleotides. Show Answer Correct Answer: D) 2'OH group in the sugar of its nucleotides. 10. To initiate the translation the mRNA first binds to ..... A) Smaller ribosome. B) Larger ribosome. C) Whole ribosome. D) No such specificity exists. Show Answer Correct Answer: A) Smaller ribosome. 11. The main enzyme in DNA replication is A) DNAse. B) Proteinase. C) DNA Polymerase. D) RNAse. Show Answer Correct Answer: C) DNA Polymerase. 12. During translation, the role of enzyme peptidyl transferase is A) Peptide bond formation between adjacent amino acids. B) Amino acid activation. C) Transfer of phosphate group. D) Binding of ribsosome subunits to mRNA. Show Answer Correct Answer: A) Peptide bond formation between adjacent amino acids. 13. In double helical structure of DNA the pitch of helix is- A) 3.4 nm. B) 0.34nm. C) 34 A. D) Both a & C. Show Answer Correct Answer: D) Both a & C. 14. What is the full form of VNTR A) Variable nucleus transfer repeat. B) Valuable of number technology repeat. C) Variable number tandem repeats. D) None of the above. Show Answer Correct Answer: C) Variable number tandem repeats. 15. Phosphoester bond is formed between A) Pentose Sugar and phosphoric acid. B) Phosphoric acid of same strand. C) Pentose Sugar of same strand. D) Nucleotides of same strand. Show Answer Correct Answer: A) Pentose Sugar and phosphoric acid. 16. During DNA replication which of the following does not act as substrates? A) DATP. B) DGTP. C) DCTP. D) DUTP. Show Answer Correct Answer: D) DUTP. 17. DNA replication takes place at ..... phase of the cellcyle. A) G1. B) M. C) G2. D) S. Show Answer Correct Answer: D) S. 18. What is the correct complimentary strand for the following DNA?ATCGAG A) ATCGAG. B) TACGAG. C) TAGCTG. D) TAGCTC. Show Answer Correct Answer: D) TAGCTC. 19. The main differences between RNA and DNA in its structure are A) The pentose sugar in RNA is ribose and it contains thymine. B) The pentose sugar in RNA is deoxyribose and it contains cytosine. C) The pentose sugar in RNA is deoxyribose and it contains uracil. D) The pentose sugar in RNA is ribose and it contains uracil. Show Answer Correct Answer: D) The pentose sugar in RNA is ribose and it contains uracil. 20. In bacterial chromosome A) There are multiple sites of replication. B) Replication is very slow. C) There is no repair of DNA. D) There is one origin of replication. Show Answer Correct Answer: D) There is one origin of replication. 21. What is the enzyme involved in the transcription of DNA? A) Helicase. B) Ligase. C) RNA polymerase. D) DNA polymerase. Show Answer Correct Answer: C) RNA polymerase. 22. Select the correct process to complete:The process by which exons join after removal of introns is ..... A) Transduction. B) Recombination. C) Ligation. D) Splicing. Show Answer Correct Answer: D) Splicing. 23. A frameshift mutation could result from A) A base substitution only. B) Either an insertion or a deletion of a base. C) A base insertion only. D) A base deletion only. Show Answer Correct Answer: B) Either an insertion or a deletion of a base. 24. Pyrimidine base present in RNA in place of thymine of DNA is A) Cytosine. B) Uracil. C) Adenine. D) Guanine. Show Answer Correct Answer: B) Uracil. 25. In a n/RNA molecule, untranslated regions (UTRs) are present at A) 5'-end (before start codon). B) 3'-end (after stop codon). C) Both (a) and (b). D) 3'-end only. Show Answer Correct Answer: C) Both (a) and (b). 26. The number of base substitution possible in amino acid codons is A) 535. B) 549. C) 2645. D) 261. Show Answer Correct Answer: B) 549. 27. The following is a section of mRNA:AUC-CUA-ACC-UAG What's the anticodon for the third amino acid? A) AUG. B) UGG. C) TGG. D) ACC. Show Answer Correct Answer: B) UGG. 28. The initiator codons are A) AUG. B) GUG. C) Both of these. D) None of these. Show Answer Correct Answer: C) Both of these. 29. The distance between a base pair in a helix is approximately ..... A) 34 nm. B) 0.34 nm. C) 0.034 nm. D) 3.4 nm. Show Answer Correct Answer: B) 0.34 nm. 30. Chargaff rule states A) A = T. B) A = C. C) C = T. D) T = G. Show Answer Correct Answer: A) A = T. 31. For a repressible operon to be transcribed, which of the following must occur? A) RNA polymerase and the active repressor must be present. B) RNA polymerase cannot be present, and the repressor must be inactive. C) RNA polymerase must bind to the promoter, and the repressor must be inactive. D) A corepressor must be present. Show Answer Correct Answer: C) RNA polymerase must bind to the promoter, and the repressor must be inactive. 32. Who proved experimentally that DNA is genetic material? A) O. Avery and Colleagues. B) J. Waston and F. Crick. C) W. Arber and Colleagues. D) G. Mendel. Show Answer Correct Answer: A) O. Avery and Colleagues. 33. What is the main difference between prokaryotic and eukaryotic transcription? A) Eukaryotes have three RNA polymerases. B) Prokaryotes have introns. C) Prokaryotes have a nucleus. D) Eukaryotes have one RNA polymerase. Show Answer Correct Answer: A) Eukaryotes have three RNA polymerases. 34. Which enzyme is responsible for joining the discontinuously synthesized fragments during DNA replication? A) DNA polymerase. B) DNA ligase. C) Helicase. D) Primase. Show Answer Correct Answer: B) DNA ligase. 35. Genetic code translates the language of A) Protein into that of DNA. B) RNA into that of DNA. C) Amino acids into that of RNA. D) RNA into that of protein. Show Answer Correct Answer: D) RNA into that of protein. 36. Spliceosomes are not found in cells of; A) Fungi. B) Bacteria. C) Animals. D) Plants. Show Answer Correct Answer: B) Bacteria. 37. By which method does the DNA replicate? A) Conservative. B) Semi conservative. C) Dispersive. D) None of the above. Show Answer Correct Answer: B) Semi conservative. 38. Which of the following represents a bond between a purine and a pyrimidine (in that order)? A) C-T. B) G-A. C) G-C. D) T-A. Show Answer Correct Answer: C) G-C. 39. During DNA replication, which enzyme primarily adds nucleotides to the growing DNA strand in the 5'$\rightarrow$3' direction? A) Ligase. B) DNA polymerase. C) RNA polymerase. D) Helicase. Show Answer Correct Answer: B) DNA polymerase. 40. Which enzyme is responsible for forming phosphodiester bonds between the Okazaki fragments? A) Ligase. B) DNA Polymerase 1. C) Helicase. D) DNA Polymerase 3TagsDNA replication enzymes. Show Answer Correct Answer: A) Ligase. 41. Histone proteins are A) Basic, positively charged. B) Acidic, positively charged. C) Basic, negatively charged. D) Acidic, negatively charged. Show Answer Correct Answer: A) Basic, positively charged. 42. Read the following four statements (A-D):(A) In transcription, adenosine pairs with uracil.(B) Regulation of lac operon by repressor is referred to as positive regulation.(C) The human genome has approximately 50, 000 genes.(D) Haemophilia is a sex-linked recessive disease.How many of the above statements are right? A) Two. B) One. C) Four. D) Three. Show Answer Correct Answer: A) Two. 43. A scientist observes a base sequence of AGCTAGCTAGCT. Which of the following would be the complimentary strand? A) TAGCTAGCTAGC. B) TCGATCGATCGA. C) TTAAGGCCTTCC. D) TGCATGCATGCA. Show Answer Correct Answer: B) TCGATCGATCGA. 44. Thymine makes up 28% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be guanine? A) 22%. B) 8%. C) 72%. D) 16%. Show Answer Correct Answer: A) 22%. 45. Process of copying DNA A) Transcription. B) Replication. C) Translation. D) Inversion. Show Answer Correct Answer: B) Replication. 46. How many amino acids are coded for by this sequence of nucleotides? ATGGGAACTCCA A) 6. B) 2. C) 12. D) 4. Show Answer Correct Answer: D) 4. 47. The fully processed hnRNA is known as A) MRNA. B) SnRNA. C) TRNA. D) ScRNA. Show Answer Correct Answer: A) MRNA. 48. In a 3.2 Kbp long piece of DNA, 820 adenine bases were found. What would be the number of cytosine bases? A) 1480. B) 780. C) 1560. D) 740. Show Answer Correct Answer: B) 780. 49. Select the correct term to complete:The coding sequence of mRNA is known as ..... A) Shine-Dalgarno sequence. B) Leader sequence. C) Poly-A tail. D) Reading frame. Show Answer Correct Answer: D) Reading frame. 50. What is 5 methyl uracil A) Methylated adenine. B) Uracil. C) Thymine. D) Adenine. Show Answer Correct Answer: C) Thymine. 51. What is anti parallel nature of DNA A) Both strand run in 5 direction. B) Both strand run In 3 direction. C) One strand runs in 5 and other runs in 3 direction. D) All of these. Show Answer Correct Answer: C) One strand runs in 5 and other runs in 3 direction. 52. If a cell were unable to produce histone proteins, which of the following results would be a likely effect on the cell? A) Amplification of other genes would compensate for the lack of histones. B) Spindle fibers would not form during prophase. C) There would be an increase in the amount of DNA produced during replication. D) The cell's DNA could not be packed into its nucleus. Show Answer Correct Answer: D) The cell's DNA could not be packed into its nucleus. 53. What can be observed if both the strands are copied simultaneously during transcription? A) The segment of DNA would be coding for 2 different proteins. B) 2 RNA will be produced simulataneously, complementary to each other. C) Formation of double helical RNA. D) All of the bove. Show Answer Correct Answer: D) All of the bove. 54. What is the difference between euchromatin and heterochromatin? A) Euchromatin is inactive, heterochromatin is active. B) Euchromatin is transcriptionally active, heterochromatin is inactive. C) Euchromatin is tightly packed, heterochromatin is loosely packed. D) Euchromatin is found in prokaryotes, heterochromatin in eukaryotes. Show Answer Correct Answer: B) Euchromatin is transcriptionally active, heterochromatin is inactive. 55. Heterogeneous RNA (hnRNA) A) Can get directly involved in translation in all organisms. B) Contains exons and but lacks introns. C) Does not require processing to become active for translation. D) Is precursor of messenger RNA in eukaryotes. Show Answer Correct Answer: D) Is precursor of messenger RNA in eukaryotes. 56. If Erwin Chargaff finds that 36% of a particular frog's DNA bases are thymine, then what percent of the DNA bases are either cytosine or adenine? A) 50%. B) 28%. C) 36%. D) 72%. Show Answer Correct Answer: A) 50%. 57. Taylor conducted the experiments to prove semi-conservative mode of chromosome replication on A) Vicia faba. B) Drosophila melanogaster. C) E. coli. D) Vinca rosea. Show Answer Correct Answer: A) Vicia faba. 58. Scientists at a university are examining a molecule that contains sugar, phosphate, adenine, and uracil. Which of the following molecules is being examined? A) Enzyme. B) Protein. C) DNA. D) RNA. Show Answer Correct Answer: D) RNA. 59. Bacteriophage $\lambda$ has A) 485020 bp. B) 48502 bp. C) 4850002 bp. D) 485000 bp. Show Answer Correct Answer: B) 48502 bp. 60. DNA has the following bases:GGT AGG CCAWhat mRNA would be created from this strand? A) CCA TCC CCT. B) CCT TCC CCA. C) GGU UCC CCA. D) CCA UCC GGU. Show Answer Correct Answer: D) CCA UCC GGU. ← 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