Buckingham - Chapter 8 - Gene Mutations

1. Substitution of leucine with valine in an amino acid sequence is what type of mutation?

A. Conservative

B. Nonconservative

C. Silent

D. Nonsense

A. Conservative

2. The codon UGG is mutated to UGA. What will happen to the encoded protein?

A. The amino acid length will increase.

B. Premature termination will occur.

C. The mutated protein will be more hydrophilic.

D. There will be no effect.

B. Premature termination will occur.

3. Which is a frameshift mutation?

A. The loss of one codon

B. A 3-base insertion

C. A 6-base deletion

D. A 2-base deletion

D. A 2-base deletion

4. Which of the following mutations is more likely to result in a phenotypic change?

A. Frameshift mutation at the beginning of the coding sequence

B. Nonconservative mutation at the end of the coding sequence

C. Silent mutation in the middle of the coding sequence

D. Conservative mutation at the end of the coding sequence

A. Frameshift mutation at the beginning of the coding sequence

5. The enzyme-linked immunosorbent assay (ELISA) is based on what earlier method first used to detect insulin in plasma?

A. Polymerase chain reaction (PCR)

B. Northern blot

C. Radioimmunoassay (RIA)

D. Enzyme immunoassay (EIA)

C. Radioimmunoassay (RIA)

6. Which of the following describes size-exclusion high-performance liquid chromatography (HPLC)?

A. Porous beads trap smaller molecules and exclude larger ones.

B. Tiny beads trap larger molecules and exclude smaller ones.

C. Molecules are retained by immobilized charged groups.

D. It is an inert gas mobile phase.

A. Porous beads trap smaller molecules and exclude larger ones.

7. Mass spectrometry detects what type of particles?

A. Uncharged

B. Ions

C. Very large proteins

D. Hydrophobic

B. Ions

8. What is MALDI-TOF?

A. An HPLC method

B. Gel-based electrophoresis

C. A type of mass spectrometry

D. ELISA performed under controlled conditions

C. A type of mass spectrometry

9. A single-strand conformation polymorphism (SSCP) procedure has been performed on a patient sample, and the results were compared to those from a normal reference sample. The patient bands resolved in different locations on the gel as compared with the reference bands. These results would be interpreted as which of the following?

A. The patient sample is normal.

B. The patient has a mutation in the targeted region.

C. The results are invalid.

D. The patient sample is a mixture of normal and mutated sequences.

B. The patient has a mutation in the targeted region.

10. Which of the following laboratory methods used to detect mutations relies on sequence-specific dissociation of double-stranded DNA?

A. Denaturing gradient gel electrophoresis

B. HPLC

C. Allele-specific oligomer hybridization

D. Melt-curve analysis

D. Melt-curve analysis

11. A patient with a family history of breast cancer, in which several affected relatives have a known mutation in the BRCA1 gene, is screened for the presence of the mutation by allele-specific PCR. Amplification from primers corresponding to the normal sequence was observed. Amplification was also observed with the primers complementary to the mutant sequence. Which of the following corresponds to the correct interpretation of these results?

A. The patient has a normal BRCA1 sequence.

B. The patient has a heterozygous mutation in BRCA1.

C. The patient has a homozygous mutation in BRCA1.

D. The results are not valid.

B. The patient has a heterozygous mutation in BRCA1.

12. A melt-curve analysis was performed to genotype hepatitis C virus (HCV), which has been identified in a patient. When the derivative of fluorescence was plotted versus the temperature for the patient's isolate as well as for a known genotype of HCV, the two sequences had identical peaks and thus the same Tm. Which of the following is the correct interpretation of these results?

A. The patient's HCV genotype is the same as the known genotype.

B. The patient's HCV genotype is different from the known genotype.

C. The patient has multiple HCV genotypes.

D. The patient's virus is not HCV but some other virus.

A. The patient's HCV genotype is the same as the known genotype.

13. Which of the following methodologies was used in the Human Haplotype Mapping Project?

A. Melt-curve analysis

B. Denaturing gradient gel electrophoresis

C. Protein truncation test

D. Inversion probe assay

D. Inversion probe assay

14. Which of the following methods used to detect mutations is a sequencing (polymerization)-based method?

A. Restriction fragment length polymorphisms

B. Single-strand conformation polymorphisms

C. Dideoxy DNA fingerprinting

D. Invader assay

C. Dideoxy DNA fingerprinting

15. A patient is being tested to determine whether he has the factor V Leiden mutation by PCR-RFLP analysis. PCR is performed on the patient's DNA and cut with HindIII. The fragments are resolved by gel electrophoresis, and the bands are visualized with ethidium bromide. The mutation-positive control sample had a single band of the expected size, and the mutation-negative control sample had a slightly larger band. The patient's specimen had two bands, one that was the same size as the positive control band and the other the same as the negative control. Which of the following is the correct interpretation of these results?

A. The patient does not have the factor V Leiden mutation.

B. The patient is heterozygous for the factor V Leiden mutation.

C. The patient is homozygous for the factor V Leiden mutation.

D. The results are not valid, and the assay should be repeated.

B. The patient is heterozygous for the factor V Leiden mutation.

16. Patient DNA has been mixed in separate wells with a probe that detects the 1691G>A mutation associated with factor V Leiden and a probe that detects the normal sequence. Cleavase is added to all wells, and the fluorescence is measured in each well. Fluorescence was detected in the well that included the normal probe, and no fluorescence was detected in the well containing the mutant probe. Which of the following assays was performed?

A. Invader assay

B. Nonisotopic RNase cleavage assay

C. Chemical cleavage assay

D. High-density oligonucleotide array

A. Invader assay

17. Which is critical to the success of sequence-specific PCR?

A. The 5' end of the primer must match the template.

B. The forward primer must have a higher Tm than the reverse primer.

C. The 3' base of the primer must be complementary to the template.

D. The primers must be less than 20 bases long.

C. The 3' base of the primer must be complementary to the template.

18. Which of the following methods has the highest sensitivity, specificity, and accuracy as far as detecting DNA mutations in clinical applications?

A. ELISA

B. High-density oligonucleotide array

C. PCR-RFLP

D. Single-strand conformation polymorphism

C. PCR-RFLP

19. Which of the following assays can be used in high-throughput applications?

A. Melt-curve assay

B. Heteroduplex analysis

C. PCR-RFLP

D. Homogenous MassExtend

D. Homogenous MassExtend

20. What does the g designate in g.225G>C?

A. Gene sequence

B. Gradient

C. Genomic sequence

D. Genetic

C. Genomic sequence

21. A reference segment of DNA has the following sequence: GCTCACCATGG. The fourth nucleotide is changed to an A in a particular genetic disease. How would this mutation be denoted by accepted nomenclature?

A. 4C>A

B. 8A>C

C. 4delC

D. 8insA

A. 4C>A

22. A reference segment of DNA has the following sequence: GCTCACCATGG. Insertion of AG occurs between positions 7 and 8 in a particular genetic disease. How is this mutation denoted by accepted nomenclature?

A. 7C>AG

B. 7_8insAG

C. 8delAinsAG

D. 7_8delAG

B. 7_8insAG

23. A protein with the sequence DAILMNCST is mutated such that amino acids L and M are deleted. How is this mutation noted by accepted nomenclature?

A. I3_N6del2

B. L4M

C. L4_M5del2

D. L4NfsX

C. L4_M5del2

24. The amino acid sequence DAILMNCST has an S8X mutation. Which of the following correctly describes this mutation?

A. Seven additional serine residues are inserted next to S.

B. The S is substituted with any amino acid at position 8.

C. There was a frameshift mutation at the S, producing a stop codon.

D. The S at position 8 is mutated to a nonsense codon.

D. The S at position 8 is mutated to a nonsense codon.

25. Which of the following methods can be used to screen for the presence of unknown mutations?

A. SSP-PCR

B. Allele-specific oligomer hybridization

C. High-density array

D. PCR-RFLP

C. High-density array

26. NIRCA is which type of detection assay?

A. Cleavage

B. Sequencing

C. Conversion

D. Synthesis

A. Cleavage

27. The SSCP procedure includes which of the following?

A. Hybridization and synthesis

B. Amplification and digestion

C. Denaturation and dilution

D. Digestion and resolution

B. Amplification and digestion

28. Which is the source of monoclonal antibodies?

A. Mouse plasma

B. Cell lines

C. Nude mice

D. Mouse ascites

B. Cell lines

29. Which method can detect gene mutations in situ?

A. EIA

B. RIA

C. HPLC

D. IHC

D. IHC

30. Which process is used with mass spectrometry to detect previously identified mutations?

A. Primer extension

B. Hybridization

C. RNA cleavage

D. DNA staining

A. Primer extension