問題一覧
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1.How many volumes of ethanol are added to1volume of DNA: salt soln to cause the DNA to precipitate?
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2. What type of short read files with quality scores are used to storing next generation sequencing read data?
FASTQ
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3.W/c is considered an epigenetic modification of DNA?
methylation of CpG islands in the promoter region of gene
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4. What term best describes the relatedness of sequence, the percent identity or conservation?
similarity
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5. What type of enzyme can be used to cut a chromosome into smaller fragments of DNA w/o removing any nucleotides or functional groups?
endonuclease
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6. The results of STR typing of a child,the child's mom & 3 alleged dads(AF)of the child are listed in the table.
AF2 is most likely the father of the child
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7.A PCR rxn in w/c 4 different sets of primers are used to simultaneously amplify 4 distinct loci in the same rxn tube is known as a:
multiplex PCR reaction
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8. Which of the ff is a known limitation of the uracil-N-glycosylase (UNG) chemistry commonly used for PCR contamination containment?
UNG will regain activity if temp drop below 55°C
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9. A RNA sample is isolated from peripheral blood cells of a px. When performing spectrophotometric analysis to determine the yield of RNA in the sample u find 1:40dilution of 0.5mL sample gives OD 260= 0.03125 & an OD 280= 0.01760. What is the total amount of RNA contained in the 0.5mL sample?
25ug
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10. The mode of inheritance of mitochondrial DNA:
maternal
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11. What is the purpose of the enzyme uracil-N-glycolase in a molecular diagnostics laboratory?
to remove any previously generated amplicons containing dUTP from PCR rxn
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12. The term that best describes males regarding X-linked genes is:
hemizygous
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13. DNA-based testing for the presence of MRSA uses PCR with primers specific for which gene?
mecA
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14. What is the most critical step in determining the specificity of a PCR reaction?
annealing temp
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15. Methylation of cytosine residues is involved in the alteration of gene expression in a number of cancers. W/c sequencing technique is best suited to determine if methylation of cytosine residues has taken place in the promoter region of the given gene?
bisulfite sequencing
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16. Which of the ff best depicts the general route of production in a human cell?
DNA-> mRNA -> protein
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17. Which structure is most resistant to denaturation?
RNA:RNA duplexes
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18. Which statement is true concerning the analysis of Short tandem repeats (STR)?
STR code for small cytokines
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19.DENaturation of DNA during PCR rxn refers to breakinG:
Hydrogen bonds between nitrogenous bases in base-paired nucleotides
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20. There is a bulge in the DNA double helix at a position 292 of a gene. This bulge is most likely due to which type of base mispairing?
purine:purine
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21.W/c mtd of tissue preservation is inappropriate for molecular testing?
Mercuric chloride
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22.common use 4 pulsed field gel electrophoresis is:
epidemiological typing of bacteria strains
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23. Which nucleotide has a high frequency of mutation in human Chromosomal DNA?
cytosine
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24. A translocation in w/c chromosome pair creates a BCR/ABL 1 fusion gene product asso with CML?
9;22
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25. W/c rgt generates a signal during the annealing stage of a quantitative real time PCR reaction?
Molecular Beacon
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26. The Kienow fragment of Escherichia coli DNA polymerase l is used:
in quantitative real time PCR
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27. Monitoring the load of HIV circulating in a px plasma would best be accomplished using w/c method?
real-time nucleic acid amplification
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28. W/c mtd of tissue preservation is inappropriate for molecular testing?
mercuric Cl
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29. How many types of primers are used for PCR?
2
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30. What is the conformation of DNA at 95°C?
single-stranded
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31.What chemistry joins successive nucleoTIDES of DNA?
phosphodiester bond
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32. A px sample contains 500particles/mL 200uL of sample is extracted,& DNA is eluted into 200uL. 5uL of DNA is added per PCR rxn .Calculate the ave no. of viral particles added per PCR rxn, assuming 100% extraction efficiency.
2.5
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33. Which method for quantifying DNA would be most appropriate when testing small FFPE tissue sections by next generation sequencing?
agarose gel
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34 DNA sequencing of hypervariable regions 1& 2 (HV1 & HV2) is used to:
detection of polymorphisms in human mitochondrial DNA
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35. W/c sequence represents the replicate DNA strand 5'-GGG ATC GAT GCC CCT TAA AGA GTT TAC-3'
3'-CCC TAG CTA CGG GGA ATT TCT CAA ATG-5'
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36. Probes are often used during real time PCR to quantitate the formation of specific amplicons during the reaction. Which system involves the use of 2 distinct probes to generate the fluorescent signal?
FRET
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37. molecular-based diagnostic test for M. tuberculosis uses ribosomal RNA as the target. Printers are made to be specific for which RNA subunit.
16S
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38. When quantifying the amount of genomic DNA in a sample by spectrophotometry. an OD 260 of 1.0 corresponds to what concentration of DNA?
50ug/mL
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39. The 2 allele for a sex-linked recessive dse are X & x. The mutant allele is x. What is the percentage of male offspring that would be expected to be affected by the dse from parents who have the following genotypes?MOTHER= Xx FATHER= xY
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40. Which locus is used to identify the gender of the individual from whom a DNA sample is obtained?
amelogenin
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41. Identification of G(-) isolate using MALDI-TOF is based on detection of:
Ribosomal proteins
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42. The real-time PCR curves represent dilutions of a single sample. Assuming PCR efficiency of 100%, what dilution is represented between aliquot A & aliquot B?
10-fold
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43. Which condition has the highest stringency for DNA probe hybridization?
high temp, low salt conc
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44. Which of the following nucleotides is a purINE?
adenine
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45. What is the best method to rule out the possibility of genomic DNA giving a False(+) result in a reverse transcriptase (RT)PCR reaction?
use of upstream & downstream primers that span an exon-intron-exon region of the target
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46. Reverse transcriptase would best be described as
RNA-dependent DNA polymerase
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47. Intervening sequences are found in:
precursor mRNA
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48. Amplification is most evident in which of PCR?
Log
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49. In dideoxy chain termination sequencing (Sanger method), what does a heterozygous nucleotide position look like on an electropherogram?
2peaks in the same position, one twice the height of the other
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50. Molecular-based testing was performed on a nasopharyngeal swap sample taken from a px. Results are reported as (+)lS481 (-)lS1000. These results indicate the px nasopharynx is colonized with:
Bordetella pertussis