Quiz On Gene Therapy (Ch-20)

2.

Which of the following cuts DNA molecules at specific locations?

Restriction enzymes
Gene cloning
DNA ligase
Gel electrophoresis
Reverse transcriptase

Correct Answer

A. Restriction enzymes

Explanation

Restriction enzymes are proteins that cut DNA molecules at specific locations. They recognize specific DNA sequences and cleave the DNA at those sites. This process is important in genetic engineering and molecular biology techniques, as it allows scientists to manipulate and study specific DNA fragments. Gene cloning involves the insertion of DNA fragments into vectors, DNA ligase is an enzyme that joins DNA fragments together, gel electrophoresis is a technique used to separate DNA fragments based on their size, and reverse transcriptase is an enzyme used to generate complementary DNA from RNA templates.

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3.

Which of the following separates molecules by movement due to size and electrical charge?

Restriction enzymes
Gene cloning
DNA ligase
Gel electrophoresis
Reverse transcriptase

Correct Answer

A. Gel electrophoresis

Explanation

Gel electrophoresis separates molecules based on their size and electrical charge. In this technique, a mixture of molecules is loaded onto a gel matrix, and an electric current is applied. The negatively charged molecules move towards the positive electrode, with smaller molecules moving faster than larger ones. As a result, the molecules separate into distinct bands based on their size. The gel matrix acts as a sieve, allowing smaller molecules to pass through more easily. The separation of molecules in gel electrophoresis is essential for various applications, such as DNA analysis, protein characterization, and genetic engineering.

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4.

Which of the following is used to make complementary DNA (cDNA) from RNA?

Restriction enzymes
Gene cloning
DNA ligase
Gel electrophoresis
Reverse transcriptase

Correct Answer

A. Reverse transcriptase

Explanation

Reverse transcriptase is used to make complementary DNA (cDNA) from RNA. Reverse transcriptase is an enzyme that can synthesize DNA using an RNA template. It catalyzes the reverse transcription process, where RNA is used as a template to produce complementary DNA strands. This enzyme is commonly used in molecular biology research to convert RNA molecules into DNA, allowing for further analysis and manipulation of the genetic material.

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5.

Which of the following seals the sticky ends of restriction fragments to make recombinant DNA?

Restriction enzymes
Gene cloning
DNA ligase
Gel electrophoresis
Reverse transcriptase

Correct Answer

A. DNA ligase

Explanation

DNA ligase is the correct answer because it is an enzyme that seals or joins together the sticky ends of restriction fragments during the process of recombinant DNA technology. Restriction enzymes are responsible for cutting DNA at specific sequences, gene cloning involves the insertion of DNA fragments into a vector, gel electrophoresis is used to separate DNA fragments based on size, and reverse transcriptase is an enzyme used in the synthesis of cDNA from RNA.

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6.

RFLP analysis can be used to distinguish between alleles based on differences in which of the following?

The proteins expressed from the alleles
The amount of DNA amplified from the alleles during PCR
The ability of the alleles to be replicated in bacterial cells
Restriction enzyme recognition sites between the alleles
The ability of nucleic acid probes to hybridize to the alleles

Correct Answer

A. Restriction enzyme recognition sites between the alleles

Explanation

RFLP analysis, or Restriction Fragment Length Polymorphism analysis, is a technique used to detect variations in DNA sequences. It involves the use of restriction enzymes to cut DNA at specific recognition sites. These recognition sites can vary between alleles, resulting in different fragment lengths when the DNA is cut. By comparing the fragment lengths produced by the restriction enzymes, we can distinguish between different alleles. Therefore, the correct answer is "restriction enzyme recognition sites between the alleles."

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7.

Which was developed by a British researcher and causes DNA sequences to be transferred to a membrane and identified with a probe?

Southern blotting
Northern blotting
Western blotting
Eastern blotting
RT-PCR

Correct Answer

A. Southern blotting

Explanation

Southern blotting is a technique developed by a British researcher that involves transferring DNA sequences onto a membrane and identifying them using a probe. This technique is specifically used to detect and analyze specific DNA sequences, such as gene expression or DNA methylation patterns. It is named after the scientist Edwin Southern, who first described the method in 1975.

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8.

Which describes the transfer of polypeptide sequences to a membrane to analyze gene expression?

Southern blotting
Northern blotting
Western blotting
Eastern blotting
RT-PCR

Correct Answer

A. Western blotting

Explanation

Western blotting is a technique used to transfer and analyze polypeptide sequences on a membrane. It involves the separation of proteins using gel electrophoresis, followed by transfer onto a membrane and detection using specific antibodies. This technique is commonly used to study gene expression by identifying the presence and quantity of specific proteins in a sample. Southern blotting is used for DNA analysis, Northern blotting is used for RNA analysis, Eastern blotting is not a recognized technique, and RT-PCR is a method for amplifying and detecting RNA.

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9.

Which uses reverse transcriptase to make cDNA followed by amplification?

Southern blotting
Northern blotting
Western blotting
Eastern blotting
RT-PCR

Correct Answer

A. RT-PCR

Explanation

RT-PCR, or Reverse Transcription Polymerase Chain Reaction, is a molecular biology technique that uses reverse transcriptase to convert RNA into complementary DNA (cDNA), followed by amplification of the cDNA. This technique is commonly used to study gene expression and detect RNA viruses. In RT-PCR, reverse transcriptase synthesizes a strand of cDNA from the RNA template, and then DNA polymerase amplifies the cDNA through multiple cycles of denaturation, annealing, and extension. This process allows for the detection and quantification of specific RNA molecules in a sample.

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10.

Which of the following is one of the technical reasons why gene therapy is problematic?

Most cells with an engineered gene do not produce gene product.
Most cells with engineered genes overwhelm other cells in a tissue.
Cells with transferred genes are unlikely to replicate.
Transferred genes may not have appropriately controlled activity.
MRNA from transferred genes cannot be translated.

Correct Answer

A. Transferred genes may not have appropriately controlled activity.

Explanation

One of the technical reasons why gene therapy is problematic is that transferred genes may not have appropriately controlled activity. This means that the genes that are introduced into cells may not be regulated properly, leading to potential overexpression or underexpression of the gene product. This lack of control can have negative consequences and may not achieve the desired therapeutic effect.

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11.

One possible use of transgenic plants is in the production of human proteins, such as vaccines. Which of the following is a possible hindrance that must be overcome?

Prevention of transmission of plant allergens to the vaccine recipients
Prevention of vaccine-containing plants being consumed by insects
Use of plant cells to translate non-plant derived mRNA
Inability of the human digestive system to accept plant-derived protein
The need to cook all such plants before consuming them

Correct Answer

A. Prevention of transmission of plant allergens to the vaccine recipients

Explanation

Transgenic plants are genetically modified plants that can produce human proteins, including vaccines. However, one possible hindrance that must be overcome is the prevention of transmission of plant allergens to the vaccine recipients. This means that measures must be taken to ensure that the vaccines produced by the transgenic plants do not contain any allergenic substances that could cause allergic reactions in the recipients.

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Quiz On Gene Therapy (Ch-20)

Which of the following produces multiple identical copies of a gene for basic research or for large-scale production of a gene product?

Quiz Preview

Which of the following cuts DNA molecules at specific locations?

Which of the following separates molecules by movement due to size and electrical charge?

Which of the following is used to make complementary DNA (cDNA) from RNA?

Which of the following seals the sticky ends of restriction fragments to make recombinant DNA?

RFLP analysis can be used to distinguish between alleles based on differences in which of the following?

Which was developed by a British researcher and causes DNA sequences to be transferred to a membrane and identified with a probe?

Which describes the transfer of polypeptide sequences to a membrane to analyze gene expression?

Which uses reverse transcriptase to make cDNA followed by amplification?

Which of the following is one of the technical reasons why gene therapy is problematic?

One possible use of transgenic plants is in the production of human proteins, such as vaccines. Which of the following is a possible hindrance that must be overcome?