Quiz Online 2 Working With Nucleic Acids
Questions and Answers
- 1.
The biology of gene manipulation requires facilities for the growth, containment, and processing of different types of cells and organisms.
- A.
TRUE
- B.
FALSE
Correct Answer
A. TRUEExplanation
The statement is true because gene manipulation in biology does indeed require facilities for the growth, containment, and processing of different types of cells and organisms. These facilities are necessary to create the conditions needed for manipulating genes and studying their effects. Without these facilities, it would be difficult to conduct research and experiments in gene manipulation.Rate this question:
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- 2.
Which of the following is NOT basic requirements for isolating nucleic acids?
- A.
Opening the cells in the sample to expose the nucleic acids for further processing
- B.
Separation of the nucleic acids from other cell components
- C.
Recovery of the nucleic acid in purified form
- D.
Labelling of nucleic acids
Correct Answer
D. Labelling of nucleic acidsExplanation
Labelling of nucleic acids is not a basic requirement for isolating nucleic acids. The process of isolating nucleic acids involves opening the cells in the sample to expose the nucleic acids, separating the nucleic acids from other cell components, and recovering the nucleic acid in purified form. Labelling of nucleic acids is a separate process that involves attaching a label or tag to the nucleic acids for specific purposes, such as tracking or detection, but it is not necessary for the basic isolation of nucleic acids.Rate this question:
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- 3.
If a DNA preparation is required, which of the following enzyme can be used to digest the RNA in the preparation?
- A.
Ribonuclease (RNase)
- B.
Polynucleotide kinase
- C.
DNA polymerase I
- D.
Deoxyribonuclease I (DNase I)
Correct Answer
A. Ribonuclease (RNase)Explanation
Ribonuclease (RNase) is the correct answer because it is an enzyme that specifically digests RNA. In a DNA preparation, if there is unwanted RNA present, RNase can be used to selectively break down the RNA molecules, leaving behind the DNA. This allows for a pure DNA sample to be obtained for further analysis or experiments. Polynucleotide kinase, DNA polymerase I, and deoxyribonuclease I (DNase I) are not suitable for digesting RNA in a DNA preparation.Rate this question:
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- 4.
The concentration of a solution of nucleic acid can be determined by measuring the absorbance at ________.
- A.
280 nm, using a spectrophotometer
- B.
260 nm, using a spectrophotometer
- C.
260 nm, using a DNA sequencers
- D.
280 nm, using a DNA sequencers
Correct Answer
B. 260 nm, using a spectrophotometerExplanation
The concentration of a solution of nucleic acid can be determined by measuring the absorbance at 260 nm using a spectrophotometer. Nucleic acids have a characteristic absorbance peak at 260 nm due to the presence of aromatic bases. By measuring the absorbance at this wavelength, the concentration of the nucleic acid can be determined. A spectrophotometer is the instrument used to measure the absorbance of a solution at different wavelengths, allowing for the determination of the concentration of the nucleic acid. DNA sequencers are not typically used for measuring the concentration of a nucleic acid solution.Rate this question:
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- 5.
Which of the following chemical is required for a deproteinisation stage?
- A.
Phenol
- B.
Ethanol
- C.
Methanol
- D.
Isopropanol
Correct Answer
A. Phenol -
- 6.
The technique of gradient centrifugation is often used to prepare ____________.
- A.
MRNA
- B.
TRNA
- C.
CDNA
- D.
DNA
Correct Answer
D. DNA -
- 7.
The concentration of DNA can be estimated by monitoring the fluorescence of _________ that binds between the DNA bases (intercalates).
- A.
Ethidium bromide (EtBr)
- B.
Calcium chloride (CaCl2)
- C.
Sulphur-35 (35S)
- D.
Phosphorus-32 (32P)
Correct Answer
A. Ethidium bromide (EtBr) -
- 8.
In the end labelling technique, the enzyme __________ is used to transfer the terminal phosphate group of ATP onto 5’-hydroxyl termini of nucleic acid molecules.
- A.
Ribonuclease (RNase)
- B.
Polynucleotide kinase
- C.
DNA polymerase I
- D.
Deoxyribonuclease I (DNase I)
Correct Answer
B. Polynucleotide kinaseExplanation
Polynucleotide kinase is the correct answer because it is the enzyme that transfers the terminal phosphate group of ATP onto the 5'-hydroxyl termini of nucleic acid molecules. This process is known as end labelling and is commonly used in molecular biology techniques such as DNA sequencing and DNA labeling for hybridization studies.Rate this question:
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- 9.
Nick translation relies on the ability of the enzyme ______________ to translate (move along the DNA) a nick created in the phosphodiester backbone of the DNA double helix
- A.
Ribonuclease (RNase)
- B.
Polynucleotide kinase
- C.
DNA polymerase I
- D.
Deoxyribonuclease I (DNase I)
Correct Answer
C. DNA polymerase I -
- 10.
Precipitation of nucleic acids is an essential technique that is used in a variety of applications. The two most commonly used precipitants are _______________
- A.
Phenol and methanol
- B.
Phenol and isopropanol
- C.
Alcohol and methanol
- D.
Isopropanol and ethanol
Correct Answer
D. Isopropanol and ethanol -
- 11.
Separation of charged molecules are separated based on varying rates of migration through a solid matrix when subjected to an electric field.
- A.
Affinity chromatography
- B.
Spectrophotometer
- C.
Automated DNA sequencers
- D.
Gel electrophoresis
Correct Answer
D. Gel electrophoresis -
- 12.
There are several variants of the basic DNA sequencing procedure, but the most widely used techniques are based on ___________
- A.
Affinity chromatography
- B.
Spectrophotometer
- C.
The enzymatic method
- D.
The chemical method
Correct Answer
C. The enzymatic method -
- 13.
Separation of the DNA fragments created in sequencing reactions is achieved by________
- A.
Affinity chromatography
- B.
Electrophoresis
- C.
PAGE
- D.
SAGE
Correct Answer
C. PAGE -
- 14.
When added to a DNA solution in a ratio, by volume, of 2:1 in the presence of 0.2 M salt, ethanol causes the nucleic acids to come out of solution.
- A.
TRUE
- B.
FALSE
Correct Answer
A. TRUEExplanation
When ethanol is added to a DNA solution in a ratio of 2:1 by volume, in the presence of 0.2 M salt, it causes the nucleic acids to come out of solution. This is because ethanol disrupts the hydrogen bonding between the DNA molecules, leading to their precipitation. The presence of salt helps to neutralize the negative charges on the DNA molecules, further promoting their aggregation and precipitation. Therefore, the statement "ethanol causes the nucleic acids to come out of solution" is true.Rate this question:
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- 15.
Nicks may occur naturally or may be caused by a low concentration of the nuclease DNase I in the reaction mixture.
- A.
TRUE
- B.
FALSE
Correct Answer
A. TRUEExplanation
The statement suggests that nicks, which are breaks in the DNA strands, can occur naturally or be caused by a low concentration of the nuclease DNase I in the reaction mixture. This means that the presence of nicks in DNA can be a natural occurrence or a result of the reaction conditions, specifically the low concentration of DNase I. Therefore, the correct answer is TRUE.Rate this question:
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- 16.
DNA polymerase I catalyses a strand-replacement reaction that incorporates new dNTPs into the DNA chain.
- A.
TRUE
- B.
FALSE
Correct Answer
A. TRUEExplanation
DNA polymerase I is an enzyme that plays a crucial role in DNA replication. It is responsible for catalyzing the strand-replacement reaction, where it removes the RNA primer and replaces it with DNA nucleotides. This process is necessary for the synthesis of a continuous DNA strand. Therefore, the statement that DNA polymerase I catalyzes a strand-replacement reaction that incorporates new dNTPs into the DNA chain is true.Rate this question:
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- 17.
Labelling by primer extension refers to a technique that uses random oligonucleotides to prime synthesis of a DNA strand by DNA polymerase.
- A.
TRUE
- B.
FALSE
Correct Answer
A. TRUEExplanation
Labelling by primer extension is a technique where random oligonucleotides are used to initiate the synthesis of a DNA strand by DNA polymerase. This technique is commonly used in molecular biology and genetic research to label DNA fragments for various applications such as DNA sequencing or DNA hybridization studies. Therefore, the given answer "TRUE" is correct as it accurately describes the process of labelling by primer extension.Rate this question:
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- 18.
Application of radiolabelling is in the production of highly radioactive nucleic acid molecules for use in hybridisation experiments.
- A.
TRUE
- B.
FALSE
Correct Answer
A. TRUEExplanation
Radiolabelling is a technique used to attach a radioactive label to a molecule, such as nucleic acids. This allows researchers to track and study the molecule's behavior in experiments. In the case of nucleic acids, radiolabelling is commonly used in hybridization experiments, where the labeled nucleic acids are used to detect and bind with complementary sequences. Therefore, the statement that the application of radiolabelling is in the production of highly radioactive nucleic acid molecules for use in hybridisation experiments is true.Rate this question:
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Mar 18, 2023Quiz Edited by
ProProfs Editorial Team -
May 10, 2009Quiz Created by
Faunsoed
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