2017 Molecular-Techniques MCQ QP+MS

2017 Molecular Techniques MCQ 2017 / H2 / ACJC PRELIM / P1 Q131Which of the following correctly matches the step involved in Southern blotting to its purpose?StepPurposeATransferring DNA fragments from a gel to a nitrocellulose paper with the use of alkaline solutionTo permanently attach the DNA fragments to a surface and to separate the two complementary DNA strandsBAdding a radioactive probeTo bind to all DNA fragments for visualisation of the DNA bandsCAdding restriction enzymesTo digest each DNA sample into fragments of similar lengthsDElectrophoresisTo separate DNA fragments based on the amount of negative charges the fragment has2017 / H2 / AJC PRELIM / P1 Q102The diagram shows the results of DNA profiling using gel electrophoresis. What conclusion can be drawn about the DNA in bands I and II?AThe DNA in the two bands had the same base sequence.BThe DNA in the two bands had the same ratio of bases.CThe DNA in the two bands came from the same source.DThe DNA in the two bands have the same charge to mass ratio.

2017 / H2 / AJC PRELIM / P1 Q17Amount of DNA3During PCR, the amount of DNA synthesised can be traced using fluorescent primers and the measurements are shown in the following plot. The process initially goes through an exponential phase, followed by a plateau phase eventually.Time Which of the following statements is true?ADuring the exponential phase, the number of DNA molecules synthesized after 15 cycles is 152. BDuring the exponential phase, the temperature is always maintained at the optimum temperature of 72oC hence there is rapid amplification. CDuring the plateau phase, the reaction mixture is being depleted of ribonucleotides. DDuring the plateau phase, Taq polymerase may be denatured.2017 / H2 / JJC PRELIM / P1 Q164Multiple copies of a wanted DNA fragment can be made by the polymerase chain reaction (PCR). Which description of this procedure is not correct?AAfter ‘n’ turns of the PCR cycle, up to 2n copies of the wanted DNA are produced.BUsing a heat-stable enzyme, such as Taq polymerase, means that the enzyme does not lose activity over time.CUsing an enzyme with a high optimum temperature allows DNA polymerisation above the annealing temperature.DUsing specific primers means that only the wanted DNA is replicated.

2017 / H2 / MJC PRELIM / P1 Q15QUESTION 5A length of DNA from one of a pair of homologous chromosomes is shown. The target sites of EcoRI are shown by arrows and the length of DNA between the target sites is given in kilobases (kb). A mutation alters one base of the coding sequence of the site marked with an asterisk (*). This also results in the loss of a target site for EcoRI. DNA from two individuals are cut with EcoRI and the DNA fragments separated according to size, and viewed subsequently by autoradiography. Which of the following corresponds to the band patterns for individuals who are homozygous and heterozygous for this mutation respectively?

2017 / H2 / RI PRELIM / P1 Q176.When a polymerase chain reaction amplification was performed on a sample of human genomic DNA, multiple products of varying sizes were obtained, including one of the expected size. Which of the following modifications to the protocol is the most likely to eliminate the extra PCR products?Araising the annealing temperature from 52C to 58CBraising the elongation temperature from 70C to 76CCdecreasing the number of cycles from 30 to 20Ddecreasing the amount of template DNA from 1.0 µg to 0.5 µg2017 / H2 / RI PRELIM / P1 Q187.A restriction enzyme recognises specific DNA nucleotide sequences and cleaves the DNA at those positions. This can be used to detect DNA polymorphisms that are found within these sites. Why is it not always possible to use restriction fragment length polymorphism (RFLP) to detect a mutation involving a disease-causing allele?ANot all disease-causing alleles have an associated RFLP. BPoint mutations can never be distinguished using RFLP.CUse of RFLP is restricted to genetic diseases that are heritable. DThe temperature required in Southern hybridisation is unknown.

2017 / H2 / RVHS PRELIM / P1 Q128 Seven skeletons were found in an unidentified grave. To establish the relationship between these seven individuals, DNA were isolated from these skeletons and then analysed using gel electrophoresis.The results obtained from the skeletons, three children and four adults, are shown below.Child 1Child 2Child 3Adult 1Adult 3Adult 3Adult 4 Other analysis showed that all three children have the same parents. Which two adults may be the parents of these children? AAdults 1 and 2BAdults 1 and 3CAdults 2 and 3DAdults 2 and 4

2017 Molecular Techniques MCQ ANSQuestionAnswerQuestionAnswer1A2D3D4B5C6A7A8B91011