Molecular Biology Final Exam 2021-2022 KING SALMAN Univ PDF

Faculty of Medicine Foundation of Molecular Biology & Genetics Final Exam 2021/2022 By : Ahmed Alaaeldin 1. Mismatch repair is responsible for correction of which of the following DNA damages? a) Double strand break. b) Errors that occurs during replication. c) Pyrimidine dimer. d) Fra...

Faculty of Medicine Foundation of Molecular Biology & Genetics Final Exam 2021/2022 By : Ahmed Alaaeldin 1. Mismatch repair is responsible for correction of which of the following DNA damages? a) Double strand break. b) Errors that occurs during replication. c) Pyrimidine dimer. d) Frame shift mutation. 2.. The growing polypeptide chain is released from the ribosomes when : a) The 7-methyl guanosine cap is reached. b) A chain terminating tRNA binds to the ribosome. c) A chain terminating codon is reached. d) The poly A tail is reached. 3. During replication, the direction of lagging strand synthesis is: a) Varying from organism to organism. b) Random. c) 5/ - 3/ d) 3/ − 5/ 4. An antibody probe is used in which of the following blotting technique? a) Eastern. b) Western. c) Southern. d) Northern. 5. Synthesis of RNA from a DNA template is known as: a) Mutation. b) Replication. c) Translation. d) Transcription. 6. Which of the following mammalian DNA polymerase is responsible for synthesis of the leading strand? a) β b) γ c) ε d) δ 7. Which of the following is characteristic of telomerase? a) It acts as reverse transcriptase. b) It is present both in eukaryotic and prokaryotic cells. c) It contains single stranded DNA molecule. d) It elongates the leading strand. 8. Post-translation processing includes: a) Spiking. b) 5' capping. c) 3’ polyadenylation. d) Trimming. 9. Which of the following represents the nitrogenous bases distribution in RNA molecules? a) Guanine is not necessarily equal to cytosine. b) Adenine equals uracil. c) Guanine equals cytosine d) Adenine equals thymine 10. The mechanisms of synthesis of DNA and RNA are different in which of the following aspects : a) Both mechanisms require a primer. b) 30th mechanisms are carried out by polymerase enzyme. c) The direction of synthesis in the both mechanisms is from 5' to 3'. d) 30th mechanisms involve release of pyrophosphate from each nucleotide added. 11. Vitamin K is required for which of the following posttranslational modification? a) Trimming of insulin. b) Acetylation of N-terminal amino acid of histones c) y-carboxylation of glutamyl residues of prothrombin. d) Hydroxylation of prolyl residues of collagen. 12. During which phase of the cell cycle is DNA replicated? a) M phase. b) S phase. c) G1 phase. d) G2 phase. 13. A consensus sequence on DNA, called TATA box, is the site for attachment of: a) DNA-dependent RNA polymerase. b) DNA-dependent DNA polymerase. c) RNA-deperdent RNA polymerase. d) RNA-deperdent DNA polymerase. 14. Sickle cell anemia is due to: a) Missense mutation. b) Frame shift mutation. c) Silent mutation. d) Nonsense mutation. 15. The termination site for transcription is recognized by : a) Topoisomerase. b) Helicase. c) Rho factor. d) Sigma factor. 16. Deoxyribonucleotides are added to RNA primer by : a) DNA polymerase l. b) DNA polymerase II. c) DNA ligase. d) DNA polymerase Ill. 17. Eukaryotic replication differs from prokaryotic replication by which of the followings? a) It requires topoisomerase II. b) It doesn't require primer. c) It has multiple origin of replication. d) 30th leading and lagging strands are elongated by the same enzyme. 18. A plasmid is formed of: a) Double stranded circular DNA. b) Double stranded linear DNA. c) Single stranded linear DNA. d) Single stranded circular DNA. 19. mRNA splicing is defined as : a) Cutting of introns and joining of exons. b) Adding cap and poly A tail to mRNA. c) Cutting of exons and joining of introns. d) Cutting of polycistronic mRNA. 20. In eukaryotes, synthesis of mRNA is catalyzed by: a) DNA polymerase l. b) RNA polymerase l. c) RNA polymerase II. d) RNA polymerase Ill. 21. Which of the following nitrogenous base is present in RNA but absent from DNA? a) Thymine. b) Cytosine. c) Uracil. d) Guanine. 22. Restriction endonucleases are present in : a) Viruses. b) Eukaryotes. c) Human mitochondria. d) Bacteria. 23. Which of the following sentences define "a codon"? a) Formed of three bases on mRNA that specify one amino acid. b) The strong bond between two complementary nitrogen bases. c) A free-floating base that attaches to an open DNA strand. d) A protein that begins transcription by breaking apart H bonds. 24. The histones of chromatid are : a) Neutral proteins b) Phosphoproteins. c) Basic proteins. d) Acidic proteins. 25. The melting temperature of DNA is the temperature at which: a) Half of the helical structure of DNA is lost. b) DNA charges from double helix into supercoiled DNA. c) DNA is hydrolysed into nucleotides. d) Solid DNA becomes liquid. 26. Fragments of DNA can be identified by the following blotting technique : a) Southern. b) Northern. c) Western. d) Eastern. 27. DNA does not contain : a) Uracil. b) Deoxyribose. c) Thym ine. d) Adenine. 28. DNA polymerase of T. aquaticus is used in PCR because: a) It doesn't cause errors in replication. b) It is not denatured at the melting temperature of DNA c) It doesn't require primers. d) It replicates DNA more efficiently. 29. Another name for reverse transcriptase is: a) DNA dependent DNA polymerase. b) DNA dependent RNA polymerase. c) RNA dependent DNA polymerase. d) RNA dependent RNA polymerase. 30. In DNA, three hydrogen bonds are formed between : a) Guanine and cytosine. b) Thymine and guanine. c) Adenine and cytosine. d) Adenine and thymine. 31. N-linked glycosylation of proteins occurs at which of the following amino acid residues: a) Arginine. b) Asparagine. c) Serine. d) AJarire. 32. The unwound strands of DNA are held apart by: a) Single strand binding protein. b) Topoisomerases I & II. c) Helicase. d) Double strand binding protein. 33. Degeneracy of genetic code means that : a) One codon can code for more than one amino acids. b) Specific codon decodes many amino acids. c) More than one codons can code for the same amino acids. d) Codons do not code for specific amino acid. 34. Xeroderma pigmentosum results from a defect in: a) Nucleotide excision repair. b) Base excision repair. c) Mismatch Repair. d) Non-homologous end joining (NHEJ). 35. The amino acid sequence of the encoded protein is not changed in: a) Missense mutation. b) Silent mutation. c) Frame shift mutation. d) Nonsense mutation. 36. Translation results in the formation of : a) mRNA b) A protein molecule. c) rRNA d) tRNA. 37. tRNA transfers : a) Amino acids from cytosol to ribosomes. b) Proteins from ribosomes to cytosol. c) Information from DNA to ribosomes. d) Information from mRNA to cytosol. 38. The enzyme amino acyl tRNA synthetase is involved in: a) Binding of tRNA with specific amino acids. b) Termination of protein synthesis. c) Formation of peptide bonds between amino acids. d) Dissociation of the empty tRNA from 80S ribosome. 39. Exposure of DNA to ultraviolet radiation can lead to the formation of: a) Adenine dimers b) Thymine dimers. c) Uracil dimers. d) Guanine dimers. 40. What directional flow of information is referred to as the "central dogma of molecular a) DNA RNA Protein. b) Protein RNA DNA c) DNA protein RNA. d) RNA DNA protein.