MCQOPTIONS
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MCQOPTIONS
This section includes 88 Mcqs, each offering curated multiple-choice questions to sharpen your Structured Query Language (SQL) knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which of the following is used to determine the appropriate stringency (Wallace rule)? |
| A. | Tm = 2 x (No.of G:C base pair) + 4 x (No.of A:T base pair) |
| B. | Tm = 4 x (No.of A:T base pair) + 2 x (No.of G:C base pair) |
| C. | Tm = 4 x (No.of G:C base pair) + 2 x (No.of A:T base pair) |
| D. | Tm = 69.3° + 0.41 (%)G+C -650/1 |
| Answer» D. Tm = 69.3° + 0.41 (%)G+C -650/1 | |
| 2. |
In the study of one experiment it was found that the value of Tm for DNA is = 40° C. If the cell has 20% GC at the above Tm, then what will be value of 'Tm' if the GC% increases to 60%? |
| A. | Remains same |
| B. | Increases |
| C. | Decreases |
| D. | Can not be compared |
| Answer» C. Decreases | |
| 3. |
Without telomerase, what would happen to the ends of chromosomes after each round of replication? |
| A. | Chromosomes would become progressively shorter |
| B. | Nothing would happen |
| C. | Chromosomes would get longer |
| D. | none of the above |
| Answer» B. Nothing would happen | |
| 4. |
An RNA primer is synthesized by |
| A. | DNA helicases |
| B. | ligase |
| C. | DNA topoisomerase |
| D. | primase |
| Answer» E. | |
| 5. |
Proteins which help to open the double helix for DNA synthesis are |
| A. | DNA helicases |
| B. | single stranded binding proteins |
| C. | ligase |
| D. | DNA topoisomerase |
| Answer» B. single stranded binding proteins | |
| 6. |
Which polymerase is active in DNA repairing |
| A. | Polymerase I |
| B. | Polymerase II |
| C. | Polymerase III |
| D. | none of these |
| Answer» C. Polymerase III | |
| 7. |
The DNA polymerase in bacteria, responsible for DNA synthesis is |
| A. | Polymerase I |
| B. | Polymerase II |
| C. | Polymerase III |
| D. | all of these |
| Answer» D. all of these | |
| 8. |
There is a single origin for DNA replication in bacteria. How many origins of replication are found in the much larger genomes of eukaryotes such as mammals? |
| A. | One |
| B. | About 100 |
| C. | Thousands and tens of thousands |
| D. | none of these |
| Answer» D. none of these | |
| 9. |
After one replication in 15N, how many bands should be observed in a cesium chloride gradient? |
| A. | One |
| B. | Two |
| C. | Three |
| D. | A smear |
| Answer» B. Two | |
| 10. |
In a cesium chloride gradient, DNA labeled with 15N and centrifuged will form a band |
| A. | above DNA containing 14N |
| B. | below DNA containing 14N |
| C. | with 14N-containing DNA |
| D. | all of these |
| Answer» C. with 14N-containing DNA | |
| 11. |
An important difference between eukaryotic and prokaryotic DNA replication is |
| A. | eukaryotic DNA polymerases are faster |
| B. | more DNA polymerases are found in eukaryotes |
| C. | multiple origins of replication in eukaryotes |
| D. | RNA primers are not required in eukaryotes |
| Answer» D. RNA primers are not required in eukaryotes | |
| 12. |
DNA replication results in |
| A. | two completely new DNA molecules |
| B. | two DNA molecules such that each one contains a strand of the original |
| C. | one new DNA molecules 1 old molecule |
| D. | one new molecule of RNA |
| Answer» C. one new DNA molecules 1 old molecule | |
| 13. |
Okazaki fragments occur on the __________ and are bonded together by __________ |
| A. | Leading strand, polymerase |
| B. | mRNA, anticodons |
| C. | Lagging strand, ligase |
| D. | tRNA, polymerase |
| Answer» D. tRNA, polymerase | |
| 14. |
The nicks or gaps between Okazaki fragments are eventually sealed by |
| A. | gyrase |
| B. | DNA ligase |
| C. | RNA ligase |
| D. | polymerase |
| Answer» C. RNA ligase | |
| 15. |
Overwinding or overtightening of DNA during replication is caused and removed by |
| A. | DNAb, DNA polymerase |
| B. | DNAa, gyrase |
| C. | DNAb, gyrase |
| D. | Single stranded protein, DNAa |
| Answer» D. Single stranded protein, DNAa | |
| 16. |
The rapid appearance of HIV-1 strains that are resistant to AIDS drugs is due in part to which of the following property of its reverse transcriptase? |
| A. | AZT (zidovudine) is too expensive to be taken in effective doses |
| B. | The RNase H domain of p66 causes error prone synthesis |
| C. | It lacks a proofreading exonuclease |
| D. | It has low affinity for the correct dNTP's |
| Answer» D. It has low affinity for the correct dNTP's | |
| 17. |
The melting of 40-45 bp at the oriC site of E. coli requires |
| A. | DNA + ATP + HU |
| B. | DNA + ATP + HU + DNAb |
| C. | DNA+ ATP + HU + DNAb + DNAa |
| D. | DNA + ATP + HU + DNAb + DNAa + Pol III holoenzyme |
| Answer» B. DNA + ATP + HU + DNAb | |
| 18. |
The RNA primers used to initiate replication in E. coli |
| A. | result in Okazaki fragments on leading strand |
| B. | are removed by Pol I |
| C. | are joined together by DNA ligase |
| D. | are removed by helicase + ATP |
| Answer» C. are joined together by DNA ligase | |
| 19. |
Reverse transcriptase produces |
| A. | DNA from peptides |
| B. | RNA from DNA |
| C. | RNA from RNA |
| D. | DNA from RNA |
| Answer» E. | |
| 20. |
Replication in E. coli is initiated by the generation of short RNA primers using |
| A. | RNA polymerase |
| B. | primase |
| C. | reverse transcriptase |
| D. | both (a) and (b) |
| Answer» E. | |
| 21. |
The 5' and 3' numbers are related to the |
| A. | length of the DNA strand |
| B. | carbon number in sugar |
| C. | the number of phosphates |
| D. | the base pair rule |
| Answer» C. the number of phosphates | |
| 22. |
The role of primase is to |
| A. | dismantle RNA primer |
| B. | cleave and unwinds short sections of DNA ahead of the replication fork |
| C. | proofread base pairing |
| D. | synthesize an RNA primer to begin the elongation process |
| Answer» E. | |
| 23. |
What is the name given to the points at which a DNA helix is unwound and new strands develop? |
| A. | Replication origins |
| B. | Replication forks |
| C. | Leading strands |
| D. | Okazaki fragments |
| Answer» C. Leading strands | |
| 24. |
Which of the following are short nucleotides strands made by DNA polymerase working in the opposite direction of the replication fork? |
| A. | Leading strands |
| B. | Okazaki fragments |
| C. | Primers |
| D. | Lagging strand |
| Answer» C. Primers | |
| 25. |
Which enzyme catalyzes the elongation of DNA molecules? |
| A. | DNA polymerase |
| B. | Helicase |
| C. | DNA ligase |
| D. | Primase |
| Answer» B. Helicase | |
| 26. |
One hypothesis of DNA replication suggested that the parental DNA molecules are broken into fragments. Both strands of DNA in each of the daughter molecules are made up of an assortment of parental and new DNA. This statement refers to which hypothesis? |
| A. | Conservative theory |
| B. | Dispersive theory |
| C. | Semi-conservative theory |
| D. | Evolutionary theory |
| Answer» C. Semi-conservative theory | |
| 27. |
What is the IUPAC code for an A, C, T ambiguity in a nucleic acid sequence? |
| A. | B |
| B. | H |
| C. | S |
| D. | None of these |
| Answer» C. S | |
| 28. |
How does ethidium bromide interact with DNA? |
| A. | It binds to adenine |
| B. | It binds to phosphate |
| C. | It intercalates between bases |
| D. | It does not interact |
| Answer» D. It does not interact | |
| 29. |
In a typical electrophoresis experiment, larger fragments of DNA move more |
| A. | slowly, so they appear nearer the top of a gel photograph |
| B. | quickly, so they appear nearer the top of a gel photograph |
| C. | slowly, so they appear nearer the bottom of a gel photograph |
| D. | quickly, so they appear nearer the bottom of a gel photograph |
| Answer» B. quickly, so they appear nearer the top of a gel photograph | |
| 30. |
DNA segments capable of moving from one place in the genome to another is known as |
| A. | transposons |
| B. | retrovirus |
| C. | introns |
| D. | moving elements |
| Answer» B. retrovirus | |
| 31. |
An enzyme that recognizes foreign DNA, and results in a cut in that DNA is called |
| A. | transposase |
| B. | helicase |
| C. | reverse transcriptase |
| D. | restriction endonuclease |
| Answer» E. | |
| 32. |
Which of these drugs bind to DNA and cuts it, producing hydroxyl radicals? |
| A. | Bleomycin |
| B. | Erythromycin |
| C. | Tunicamycin |
| D. | All of these |
| Answer» B. Erythromycin | |
| 33. |
The site on a bacterial chromosome that marks the initiation point for chromosome replication is called |
| A. | Ori |
| B. | a promoter |
| C. | Pro |
| D. | an initiation codon |
| Answer» B. a promoter | |
| 34. |
The enzyme responsible for breaking the hydrogen bonds, and thus separating the DNA strands during DNA synthesis is |
| A. | DNA polymerase |
| B. | strandase |
| C. | helicase |
| D. | none of these |
| Answer» D. none of these | |
| 35. |
In DNA replication, one new strand is synthesized complementary to an old (parent) strand and is referred as |
| A. | mutational |
| B. | semiconservative |
| C. | discontinuous |
| D. | antiparallel |
| Answer» C. discontinuous | |
| 36. |
What does ligase do during replication of DNA? |
| A. | Synthesizes the lagging strand |
| B. | Makes copies of mRNA from DNA |
| C. | Joins nicks in DNA strands |
| D. | Digests mRNA when it is no longer needed |
| Answer» D. Digests mRNA when it is no longer needed | |
| 37. |
Which of the following in DNA replication and transcription are common? |
| A. | incorporation of deoxynucleotides |
| B. | utilization the same enzyme |
| C. | synthesis in the 5'-3' direction |
| D. | none of the above |
| Answer» D. none of the above | |
| 38. |
Which will require a higher temperature to denature? |
| A. | DNA with a high G-C content |
| B. | DNA with a high A-T content |
| C. | RNA with a high G-C content |
| D. | RNA with a high A-T content |
| Answer» B. DNA with a high A-T content | |
| 39. |
The size of a linear DNA fragment in a gel can be estimated by |
| A. | fluorescence in UV light |
| B. | the sedimentation coefficient |
| C. | the time it takes the gel to run |
| D. | comparison with a molecular weight standard such as Hind III digested phage lambda |
| Answer» E. | |
| 40. |
The replication of a linear DNA molecule in a eukaryotic chromosome creates a problem which is reported to be sorted out by |
| A. | using enzyme called telomerase |
| B. | shortening of the double stranded replicated portion |
| C. | using RNA as a template |
| D. | none of the above |
| Answer» B. shortening of the double stranded replicated portion | |
| 41. |
DNA replication in eukaryotes occurs only in |
| A. | G1 phase |
| B. | S phase |
| C. | G2 phase |
| D. | M phase |
| Answer» C. G2 phase | |
| 42. |
For the DNA replication in eukaryotes, the cell cycle consists of |
| A. | G1, G2 and M phases |
| B. | S, G2 and M phases |
| C. | G1,S, G2 and M phases |
| D. | G2 and M phases |
| Answer» D. G2 and M phases | |
| 43. |
Each replication bubbles consists of |
| A. | 3 replication forks |
| B. | 2 replication forks |
| C. | 4 replication forks |
| D. | 1 replication forks |
| Answer» C. 4 replication forks | |
| 44. |
Automated DNA sequencing uses the chain termination method |
| A. | but with an oligonucleotide primer labeled with a fluorescent dye |
| B. | but with a polynucleotide primer labeled with a fluorescent dye |
| C. | with no primer |
| D. | either (b) or (c) |
| Answer» B. but with a polynucleotide primer labeled with a fluorescent dye | |
| 45. |
Deoxyribonucleoside triphosphates, being need in the chain termination methods are |
| A. | dATP |
| B. | dGTP and dCTP |
| C. | dTTP |
| D. | all of these |
| Answer» E. | |
| 46. |
DNA polymerases I also has |
| A. | 5'-3' exonuclease activity |
| B. | 3'-5'exonuclease activity |
| C. | both (a) and (b) |
| D. | 5'-3' endonuclease activity |
| Answer» C. both (a) and (b) | |
| 47. |
Which of the following is an active site on its single polypeptide chain for DNA Polymerase I? |
| A. | 5' → 3' polymerase |
| B. | 3' → 5' exonuclease |
| C. | 5' → 3' exonuclease |
| D. | all of the above |
| Answer» B. 3' → 5' exonuclease | |
| 48. |
E.coli DNA polymerases II and III lack |
| A. | 5' → 3' exonuclease activity |
| B. | 5' → 3' endonuclease activity |
| C. | partially 5' → 3' exonuclease activity |
| D. | partially 5' → 3' endonuclease activity |
| Answer» B. 5' → 3' endonuclease activity | |
| 49. |
Which of the following species lack a 'classical' histone H1? |
| A. | Saccharomyces cerevisiae |
| B. | Strongylocentrotus purpuratus |
| C. | Xenopus laevis |
| D. | Arabidopsis thaliana |
| Answer» B. Strongylocentrotus purpuratus | |
| 50. |
During conventional transformation experiments E. coli cells and plasmid DNA interacts in an environment of |
| A. | high temperature and Ca++ |
| B. | low temperature and Ca++ |
| C. | high temperature and Mg++ |
| D. | low temperature and Mg++ |
| Answer» C. high temperature and Mg++ | |