Deck 4: Concepts in Molecular Biology

Question 1

Which of the following sequences is recognized by ecoRI?

A) 5'GAATTC3'
B) 5'CTCTTG3'
C) 5'CGCG3'
D) 5'AGCT3'

Answer 1

A

Question 2

A codon consists of how many nucleotides?

A) 1
B) 2
C) 3
D) 4

Answer 2

C

Question 3

How does the Northern blotting technique differ from the Southern blotting technique?

A) In the Northern blotting technique, RNA is detected instead of DNA.
B) Gel electrophoresis is not used in the Northern blotting technique.
C) In the Northern blotting technique, cDNAs are used in place of restriction endonucleases.
D) All of the above

Answer 3

A

Question 4

Restriction endonucleases are characterized as being palindromic. What is meant by this term?

A) The recognition sequence is read in the same 5' to 3' direction on both strands of the double helix.
B) The recognition sequence is read in the same 3' to 5' direction on both strands of the double helix.
C) The recognition sequence is read in the same 5' to 3' direction on one side of the double helix.
D) The recognition sequence is read in the same 3' to 5' direction on one side of the double helix.

Question 5

What is the function of helicases and gyrases in the polymerase chain reaction?

A) To unwind the DNA
B) To anneal to cDNA sequences
C) To extend the primer sequence
D) To generate blunt-ended, double-stranded products

Question 6

Gel electrophoresis is a useful tool in DNA cloning. At a neutral pH, when voltage is applied, DNA fragments will migrate toward the anode because:

A) DNA is negatively charged due to its glycine backbone.
B) DNA is negatively charged due to its phosphate backbone.
C) DNA is positively charged due to its glycine backbone.
D) DNA is positively charged due to its phosphate backbone.

Question 7

Which of the following are described as bacterial circular genetic elements that replicate independently from the chromosome and are capable of conferring bacterial resistance to certain antibiotics in DNA cloning?

A) Introns
B) Extrons
C) Codons
D) Plasmids

Question 8

Which of the following is representative of the lagging strand in DNA replication?

A) RNA polymerase catalyzes a primer that provides the 3'OH to which DNA polymerase III can add nucleotides.
B) DNA polymerase catalyzes a primer that provides the 5'OH to which RNA polymerase can add nucleotides.
C) DNA telomerase catalyzes a primer that provides the 3'OH to which RNA polymerase can add nucleotides.
D) DNA ligase catalyzes a primer that provides the 5'OH to which RNA polymerase can add nucleotides.

Question 9

In DNA cloning, the DNA fragment of interest carried by the is introduced into a host cell.

A) plasmid
B) vector
C) protein
D) restriction endonucleases

Question 10

In this procedure, PCR products are blotted in a nylon filter and hybridized with specific probes that allow the distinction of the different known alleles.

A) Sequence-specific PCR
B) Sequence-specific oligonucleotide probe
C) Sequence-specific RFLP
D) Allele-specific PCR

Question 11

Which of the following is not consistent with the structure of DNA?

A) The double helix consists of two strands of nucleotides, which are antiparallel.
B) At each turn of the helix, 10 base pairs are stacked on top of each other.
C) The double helix consists of two strands of nucleotides, which are parallel.
D) The helical ladder is built from alternating units of deoxyribose and phosphate.

Question 12

How can genomic DNA be obtained?

A) Lysis of peripheral blood mononuclear cells with a hypotonic solution and proteinase K
B) Lysis of bone marrow mononuclear cells with a hypertonic solution and proteinase K
C) Lysis of peripheral blood mononuclear cells with an isotonic solution and proteinase K
D) Lysis of bone marrow mononuclear cells with an isotonic solution and proteinase K

Question 13

are regions of DNA interspersed in the human genome formed by variable tandem repeats of short nucleotide sequences used in DNA fingerprinting.

A) Minisatellites
B) Macrosatellites
C) Platelet satellites
D) Chromatids

Question 14

In this technique, fluorescent probes are used to detect homologous DNA or RNA sequences in chromosomes or intact cells.

A) PCR
B) FISH
C) RFLP
D) DNA sequencing

Question 15

Which of the following is representative of the "central dogma" of molecular biology?

A) The basic information of life flows from DNA through RNA to proteins.
B) The basic information of life flows from RNA through DNA to proteins.
C) The basic information of life flows from proteins to genes.
D) The basic information of life flows from amino acids to proteins.

Question 16

What are ddNTPs?

A) Deoxyribonucleoside triphosphates
B) Dideoxyribonucleoside triphosphates
C) Deaminase deoxyribonucleoside triphosphates
D) Dodecyl deoxyribonucleoside triphosphates

Question 17

All of the following make up three branches of molecular biology related to transfusion medicine except:

A) molecular genetics.
B) biotechnology.
C) molecular diagnostics.
D) paternity.

Question 18

Which of the following statements regarding the DNA molecule is false?

A) Cytosine always pairs with guanine.
B) Adenine always pairs with thymine.
C) Adenine always pairs with uracil.
D) Options A and B

Question 19

Which of the following is false regarding the Southern blotting technique?

A) DNA is digested with one or more restriction endonucleases, and the fragments are separated by gel electrophoresis.
B) Gel is placed over a nitrocellulose membrane.
C) A labeled probe is used to detect bands of interest.
D) Membrane-bound fragments have different positions as the fragments separated by size on the gel electrophoresis.

Question 20

All of the following are examples of recombinant proteins used in transfusion medicine except:

A) G-CSF.
B) stem cell factor.
C) epoetin alpha.
D) factor VIII.

Question 21

Restriction Fragment Length Polymorphism (RFLP) can be used for all but which of the following purposes?

A) In paternity cases to determine the source of a DNA sample
B) To measure recombination rates, which can lead to a genetic map with the distance between RFLP loci measured in centimorgans
C) In criminal cases to determine the source of a DNA sample
D) To determine the Rh status of an individual

Question 22

Southern blotting techniques are mostly being replaced by .

A) Northern blotting techniques
B) Eastern blotting techniques
C) polymerase chain reaction-based methods
D) all of the above

Question 23

Biotechnology is important in blood banking because of:

A) its production of growth factors.
B) its production of erythropoietin.
C) its production of clotting factors.
D) all of the above.

Question 24

Gene transfer between two bacterial strains is an example of:

A) Mendel's law.
B) Griffith's transformation.
C) Oswald's principle of heredity transformation.
D) Chargaff's rules.

Question 25

Molecular RBC antigen typing is used:

A) to confirm serological testing.
B) when serology is not possible.
C) when serology is not sensitive enough or discrepancies occur.
D) for all of the above.

Question 26

During protein biosynthesis combines the codons of mRNA with its anticodons.

A) DNA
B) tRNA
C) uracil
D) reverse transcriptase

Question 27

In nucleic acid hybridization, nucleic acid hybrids can be formed between.

A) two strands of DNA
B) two strands of RNA
C) one strand of RNA and one strand of DNA
D) all of the above

Question 28

Single-stranded RNA can be transcribed into single-stranded DNA by what enzyme?

A) Polymerase
B) DNAse
C) Reverse transcriptase
D) Endonuclease

Question 29

Which of the following blood groups is coded by variants of a single gene?

A) Rh
B) Xg
C) MNS
D) Chido/Rodgers
E) Lutheran

Question 30

What is a major advantage of PCR?

A) Primers can be reused.
B) It uses a small amount of DNA.
C) Probes can come from several sources.
D) DNA can be single stranded.

Question 31

Which of the following statements is false?

A) Transcription mediated amplification is a form of NAT.
B) Serological testing for antibodies shortens the preconversion window period for testing the safety of donor units for the national blood supply.
C) PCR and ligase chain reaction are both examples of NAT.
D) NAT allows the detection of pathogens before the appearance of testable immune response.

Question 32

All of the following are sources of DNA for performing Southern blot analysis except:

A) bone marrow.
B) leukocytes.
C) cell cultures.
D) pericardial fluid.

Question 33

An advantage to cloning using the polymerase chain reaction is that it can be done completely .

A) in vitro
B) in vivo
C) in situ
D) in utero

Question 34

Gel electrophoresis allows for:

A) isolation of DNA fragments.
B) purification of DNA fragments.
C) visual examination of a defined-length DNA fragment.
D) all of the above.

Question 35

All of the following are examples of vectors except:

A) plasmids.
B) lambdas.
C) cosmids.
D) chirons.

Question 36

Risks for using retroviruses, adenoviruses, and lentiviruses as vectors in gene therapy include all of the following except:

A) the exogenous gene may cause disease if overexpressed or expressed in certain cell types.
B) contaminants may be introduced during vector manufacture.
C) antitumor responses by overexpression of cytokines may occur.
D) there is a potential for recombination of gene therapy vectors with human endogenous sequences.

Question 37

What is a disadvantage of using ethidium bromide (EB) as a dye in electrophoresis studies?

A) It is expensive.
B) It is mutagenic.
C) It is rare and difficult to obtain.
D) It fades quickly after use.

Question 38

Which of the following best describes the principle of polymerase chain reaction (PCR)?

A) Migration of proteins in an electrical field
B) Amplification of RNA using two oligonucleotide primers that hybridize to opposite DNA strands
C) Amplification of DNA using two oligonucleotide primers that hybridize to opposite DNA strands, isolating a particular segment
D) Enzymatic cleavage of proteins for DNA sequencing

Question 39

In performing gene cloning for blood group genes, what is a possible source of RNA?

A) Lymphocytes
B) Reticulocytes
C) Neutrophils
D) Platelets

Question 40

The process of translation and transcription is referred to as:

A) the genetic code.
B) central dogma.
C) gene expression.
D) spectral analysis.

Question 41

What technique did Rosalind Franklin use to show the helical structure of DNA?

A) Gas chromatography
B) Infrared spectrum
C) Mass spectrometry
D) X-ray diffraction

Question 42

Which formula demonstrates Chargaff's rule?

A) A + G = T + C
B) A + T = G + C
C) A + C = G + T

Question 43

In the science of trans-blotting techniques, Southern is to DNA as Western is to:

A) carbohydrates.
B) enzymes.
C) lipids.
D) proteins.

Question 44

What blood grouping information can be ascertained from RFLP analysis?

A) Rh factor
B) HLA phenotype
C) Sda
D) Polyagglutination

Question 45

Each type of tRNA molecule can be attached to only one type of amino acid, but because the genetic code contains multiple codons that specify the same amino acid, tRNA molecules bearing different anticodons may also carry the same amino acid.