MLT 230 Clinical Chemistry, Unit 5 (101-139)
137) Match the hormone with the disease or condition produced by that hormone's hypersecretion or hyposecretion. a.Precocious puberty b.Polycystic ovary syndrome c.Galactorrhea d.Inability to maintain endometrium 1. Prolactin 2. Testosterone 3. Progesterone 4. LH
1. C 2. A 3. D 4. B
136) Match the specific hormone with its clinical usefulness. a.Occurrence of ovulation b.Assesses ovarian function c.Screens for fetal Down syndrome d.Assesses amenorrhea 1. Estriol (E3) 2. Prolactin 3. Estradiol (E2) 4. LH
1. C 2. D 3. B 4. A
105) The annealing step in a PCR involves: a.binding of the primers to the single-stranded DNA. b.unwinding and separating the double-stranded DNA. c.adding nucleotides to primed sites of the DNA strands. d.making a cDNA from an mRNA strand.
A
109) In a pyrosequencing reaction, the incorporation of a nucleotide releases _____. Eventually, visible light is produced by an enzyme reaction. a.pyrophosphate b.ATP c.luciferase d.a primer
A
114) When combined with real-time PCR, melting curve analysis is done to: a.examine a single nucleotide variant genotype in a short amount of time. b.quickly quantify the amplified target. c.detect nucleic molecules at a specific wavelength. d.examine the size of a fragment produced by RFLP.
A
117) Which one of the following is the name given to the probe types used in real-time PCR that change fluorescence through fluorescence resonance energy transfer (FRET) upon duplex formation? a.Hybridization b.Hydrolysis c.Mixed mechanism d.Primer
A
123) Polymorphic DNA sequences that are short tandem repeats 1 to 13 base pairs in length are referred to as: a.microsatellites. b.minisatellite DNA. c.long tandem repeats. d.transposable elements.
A
127) Which one of the following statements regarding the human genome below is correct? a.Mobile genetic elements (transposons) comprise almost half of the human genome. b.An intron is located within a transposon segment of a chromosome. c.Genes that contain instructions for making proteins are located in transposons. d.Unique sequences that code for protein make up only 10% of the human genome.
A
131) A virus does not need as much nucleic acid for the production of protein as bacteria do because: a.viruses use the DNA of the cells that they infect to produce protein. b.viruses contain high sequence variation. c.there are no introns in the viral genome. d.it uses plasmids to synthesize protein instead of DNA.
A
101) In real-time PCR: a.an isolated mRNA and Thermus thermophilus is used. b.one can observe amplified nucleic acid fragments as they are synthesized. c.RNA:DNA hybrids are bound to a solid phase. d.RNA targets are used in an isothermal reaction.
B
102) False positive results in molecular testing are most likely caused by which one of the following? a.Inhibitors present in the sample b.Contamination with amplicon c.Lengthy specimen prep time d.Lengthy patient prep time
B
106) When performing a PCR procedure, what is the best control to run to assess the presence of amplicon? a.Positive control b.Blank control c.Oligoligated control d.dTTP control
B
107) An example of a signal amplification technique (as opposed to a target or probe amplification technique) would be: a.polymerase chain reaction. b.branched-chain amplification. c.ligase chain reaction. d.real-time PCR.
B
115) Gene expression microarrays quantify: a.a single copy of a nucleic acid target. b.relative amounts of different messenger RNAs in samples. c.RNA promoter regions that are adjacent to an inserted DNA sequence. d.the number of specific base pairs in a DNA target.
B
120) An enzyme that hydrolyzes one or more phosphodiester bonds in nucleic acid polymers is called a: a.polymerase. b.nuclease. c.ligase. d.reverse transcriptase.
B
122) A single nucleotide variant that produces a misplaced termination codon in a polypeptide chain results in: a.a frameshift mutation. b.premature polypeptide chain termination. c.chromosomal translocation. d.a trinucleotide repeat.
B
124) On average, how much of a gene sequence is removed as introns, leaving the exons to be spliced together and translated into protein? a.100% b.95% c.50% d.1%
B
126) Polymorphic repeated DNA sequences that are sometimes referred to as minisatellite sequences and are between 14 and 500 base pairs in length are called: a.transposons. b.a variable number of tandem repeats. c.a restriction endonuclease. d.short tandem repeats.
B
130) In the following sequences, the normal amino acid sequence is given first followed by the sequence that is produced by a sequence alteration. Identify the type of sequence alteration that most likely causes the altered amino acid sequence. Normal Sequence: Phe-Asn-Pro-Thr-Arg Mutated Sequence: Phe-His-Pro-Thr-Arg What type of sequence alteration most likely caused the mutation? a.Indel b.Missense c.Nonsense d.There is no alteration.
B
133) The major difference between single nucleotide variants (SNVs) and copy number variants (CNVs) is that: a.SNVs are duplicated in tandem and involve complex gains or losses of homologous sequences, whereas CNVs involve simple sequence changes. b.CNVs occur in stretches of DNA ranging from 100 to millions of bases in size, whereas SNVs involve single base changes. c.SNVs are always associated with disease, whereas CNVs are not. d.SNVs are involved in gene amplification by producing more than two functional genes in a genome.
B
104) Which one of the following statements regarding DNA gel electrophoresis is true? a.It is the charge of the pyrimidines in the DNA molecule that gives DNA its net negative charge and ability to migrate on a gel. b.Agarose gel can resolve 1 bp differences in DNA fragments and is best to use for DNA sequencing. c.Polyacrylamide gel can separate smaller fragments of DNA with high resolution and is best for single-stranded nucleic acid separation. d.Because of the negative charge of DNA, it will migrate toward the negative electrode during electrophoresis.
C
108) How does a dideoxynucleotide (ddNTP) that is used in DNA sequencing methods differ from a typical deoxynucleotide (dNTP) present in normal DNA? a.ddNTPs have a hydroxyl group at the 2' carbon b.ddNTPs have a hydroxyl group at the 3' carbon c.ddNTPs lack a hydroxyl group at the 3' carbon d.ddNTPs lack a hydroxyl group at the 5' carbon
C
111) If RNA is to be used in a PCR amplification procedure, what is the initial step that must be performed? a.The RNA must be denatured to form single strands for annealing to primers. b.RNA should never be used in a PCR reaction because thermostable enzymes cannot synthesize strands to anneal to it. c.A reverse transcription procedure must be performed to form cDNA. d.RNA must first be treated with RNases to remove interfering substances from the target.
C
116) Regarding detection methods, the most common and preferred sequence-specific label for probes used in nucleic acid analysis is a(n) _____ label. a.enzyme b.radioactive c.fluorescent d.colorimetric
C
118) In a PCR, a control nucleic acid sequence that is different from the target sequence is added to each sample to: a.control for the presence of amplicon contamination. b.bind aerosols. c.control for the presence of inhibitors in the sample that might inhibit polymerase activity. d.compare with an internal standard for quantitative analysis.
C
128) If you were interested in studying plasmid structure, which one of the following cell types would be appropriate for you to examine? a.Human cells b.Fungal cells c.Bacterial cells d.All cell types
C
129) In the following sequences, the normal amino acid sequence is given first followed by a sequence that is produced by a sequence alteration. Identify the type of sequence alteration that most likely causes the altered amino acid sequence. Normal Sequence: Phe-Asn-Pro-Thr-Arg Mutated Sequence: Phe-Asn-Pro What type of sequence alteration most likely caused the mutation? a.Indel b.Missense c.Nonsense d.There is no alteration.
C
135) Copy number variants comprise approximately what percent of the human genome? a.75% b.50% c.10% d.0.5%
C
103) Which of the following procedures can be used to avoid contamination with PCR reaction product (amplicon) when performing a PCR procedure? a.Use of positive displacement pipettes b.Use of closed-tube methods c.Physical separation of preamplification and postamplification rooms d.All of the above
D
110) Which one of the following statements regarding single-stranded conformational polymorphism (SSCP) analysis is incorrect? a.SSCP is used to assess a specimen for the presence of unknown variants in a nucleic acid sequence. b.SSCP distinguishes altered gene sequences by detecting a change in the three-dimensional structure of a piece of single-stranded DNA. c.SSCP is a polyacrylamide gel electrophoresis procedure. d.In SSCP, separation of a PCR product is performed with a gel that includes a concentration gradient of denaturants.
D
112) The increase in the quantifiable signal observed early on in real-time PCR is dependent upon the: a.amount of fluorescent dye added to the reaction. b.initial amount of fluorescent primer added. c.amount of fluorescent quenching. d.initial amount of target DNA.
D
113) What type of assay is hybrid capture? a.Solid-phase hybridization b.Signal amplification c.Transcription-mediated amplification d.Solution-phase hybridization
D
119) What is the purpose of the labeled oligonucleotide probe used in hybridization assays? a.To stabilize the assay b.To cut the DNA into smaller-size fragments c.To reduce the background of the assay d.To detect the presence of a specific nucleotide sequence
D
121) A single nucleotide variant (SNV) that produces a misplaced termination codon in a polypeptide chain is called a: a.missense variant. b.transposon. c.copy number variant. d.nonsense variant.
D
125) Which one of the following is a similarity between bacterial and human genomes? a.Number of chromosomes b.Structure of chromosomes c.Number of genes d.Presence of double-stranded DNA
D
132) Approximately what percentage of genomic DNA is required to maintain the structure of chromosomes as centromeres and telomeres? a.75% b.50% c.20% d.2%
D
134) An example of epigenetic variation that affects gene expression would be: a.heteroplasmy. b.chromosomal translocation. c.copy number alteration. d.histone modifications.
D
138) True or False: To evaluate ovulation, basal body temperature can be recorded. If ovulation has occurred, a rapid decrease in body temperature is noted throughout the luteal phase and is caused by progesterone
False
139) True or False: An example of a confirmatory laboratory test used to verify a borderline abnormal newborn screening test result in an asymptomatic individual would be gas chromatography combined with mass spectrometry, particularly for organic acid analysis.
True
