DNA Biotechnology Sample Questions
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- 1.Which of the following statements describing restriction endonucleases is true
- A.
They always yield overhanging single-stranded ends
- B.
They recognize methylated DNA sequences
- C.
They recognize triplet repeats
- D.
They cleave both strands of duplex DNA
- E.
They always yield blunt ends
- 2.Which of the following statements correctly describes the recombinant DNA tool know as plasmids?
- A.
They are found more commonly in viruses than in bacteria
- B.
They are single-stranded circles
- C.
They sometimes enhance bacterial susceptibility to antibiotics
- D.
They sometimes enhance bacterial resistance to antibiotics
- E.
They are too small to be useful as vectors for the cloning of mammalian DNA segments
- 3.DNA fingerprinting is used for paternity testing and forensic identification of suspects. Which of the following is the most accurate description of DNA fingerprinting?
- A.
DNA can be isolated from blood, skin, or sperm and analyzed for variable patterns of restriction fragments arising from tandemly repeated sequences (microsatellites)
- B.
DNA is copied from blood, skin, or sperm RNA using reverse transcriptase and analyzed for patterns of complementary DNAs
- C.
DNA is isolated from blood, skin, or sperm and its fragment size distribution is analyzed by gel electrophorsis
- D.
DNA is isolated from blood, skin, or sperm and hybridized with probes from the HLA locus to visualize HLA gene patterns
- E.
DNA is isolated from blood, skin, or sperm, centrifuged to separate satellite DNA fractions, and analyzed by gel electrophoresis.
- 4.Which of the following results is provided by northern blot analysis?
- A.
Detects specific base pairs
- B.
Detects DNA molecules
- C.
Detects RNA molecules
- D.
Detects proteins
- E.
Determines chromosome structure
- 5.Sickle cell anemia is caused by a point mutation in the hemoglobin gene, resulting in the substitution of a single amino acid in the b-globin peptides of hemoglobin. This mutation is best detected by which of the following?
- A.
Isolation of DNA from red blood cells followed by polymerase chain reaction (PCR) amplification and restriction enzyme digestion.
- B.
Isolation of DNA from blood leukocytes followed by Southern blot analysis to detect globin gene exon sizes
- C.
Isolation of DNA from blood leukocytes followed by DNA sequencing of globin gene introns
- D.
Isolation of DNA from blood leukocytes followed by polymerase chain reaction (PCR) amplification and allele-specific oligonucleotide (ASO) hybridization
- E.
Western blot analysis of red blood cell extracts
- 6.James K. is a Huntington disease patient who has recently been institutionalized and requires constant nursing care. His wife is unaffected, and they have a 38-year-old daughter, Delia, who has 4 children ranging in age from 8 to 15 years. Delia wishes to know whether she has inherited the disease-producing allele from her father. PCR amplification is carried out on the region containing the CAG repeat, shown below. Which of the flowing sets of primers would be used to amplify the CAG repeat in the brackets ([CAG]n)? GAG TCC CTC AAG TCC TTC [CAG]n CAA CAG CCG CCA CCG CCG
- A.
GAGTCCCTCAAGTCCTTC and CGGCGGTGGCGGCTGTTG
- B.
CTTCCTGAACTCCCTGAG and CAACAGCCGCCACCGCCG
- C.
CTTCCTGAACTCCCTGAG and CGGCGGTGGCGGCTGTTG
- D.
GAGTCCCTCAAGTCCTTC and CAACAGCCGCCACCGCCG
- E.
GAGTCCCTCAAGTCCTTC and GTTGTCGGCGGTGGCGGC
- 7.Parental relationship between a man and infant can be best determined by the technique commonly referred to as DNA fingerprinting. Which of the following sequences is most conveniently analyzed by a DNA fingerprint?
- A.
Histocompatibility loci
- B.
Centromeres
- C.
Microsatellite tandem repeats (STRs)
- D.
Restriction enzyme sites
- E.
Single-copy sequences
- 8.Sickle-cell anemia is caused by a missense mutation in codon 6 of the b-globin gene. Codon number 5 6 7 8 Normal allele CCT GAG GAG AAG Mutant allele CCT GTG GAG AAG A man with sickle-cell disease and his phenotypically normal wife request genetic testing because they are concerned about the risk for their unborn child. DNA samples from the man and the woman and from fetal cells obtained by amniocentesis are analyzed using the PCR to amplify exon 1 of the b-globin gene. Which 12-base nucleotide sequence was most likely used as a specific probe complementary to the coding strand of the sickle cell allele?
- A.
CCTCACCTCAGG
- B.
CCTGTGGAGAAG
- C.
GGACACCTCTTC
- D.
CTTCTCCACAGG
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