Question 1

Plasmids are useful to scientists involved in recombinant DNA technology because foreign genes can be inserted into the plasmids and then the plasmids can be inserted back into bacteria.

Accepted Answer

Plasmids are commonly used as vectors in recombinant DNA technology because they can carry foreign genes and can easily be inserted into bacterial cells. The inserted gene can then be expressed by the bacterial cell, allowing scientists to produce large quantities of the desired protein or product.

Question 2

Gel electrophoresis is a technique used to separate a mixture of DNA fragments. During this process, large DNA fragments move longer distances than small DNA fragments when an electric current is applied.

Accepted Answer

The answer of Gel electrophoresis is a technique used to...

Question 3

Gene therapy is currently under investigation as a possible way to cure cystic fibrosis. How is the viral vector carrying the normal gene delivered to the affected cells?

Accepted Answer

The answer of Gene therapy is currently under investigation as...

Question 4

The goal of polymerase chain reaction (PCR) is to determine the sequence of nucleotides in a stretch of DNA.

Accepted Answer

PCR is a technique used to amplify a specific stretch of DNA, but it does not determine the sequence. DNA sequencing techniques, such as Sanger sequencing or next-generation sequencing, are used to determine the sequence of nucleotides in DNA.

Question 5

During PCR, the enzyme DNA ligase is added to the mixture to promote the addition of nucleotides to the growing DNA chain.

Accepted Answer

During PCR, the enzyme DNA polymerase is used to add nucleotides to the growing DNA chain, not DNA ligase. DNA ligase is used in other molecular biology techniques, such as DNA cloning or DNA sequencing, to join together separate DNA strands.

Question 6

The idea of manipulating DNA through cutting and splicing, essential to the science of recombinant DNA technology, is not necessarily a new process since nature has been recombining DNA for billions of years.

Accepted Answer

Recombination through cutting and splicing of DNA is a natural process that has been occurring in nature for billions of years. Recombinant DNA technology simply harnesses this process for human use.

Question 7

Insertion of a gene into another organism's DNA so that it can be transferred to another organism like a bacterium is called

Accepted Answer

The process described in the question is known as vector transfer, where a foreign gene is inserted into a vector (such as a plasmid) and that vector is then introduced into the target organism (such as a bacterium) to transfer the gene. PCR (B) is a technique to amplify DNA and is not directly related to gene transfer. DNA amplification (C) is also not a specific term related to gene transfer. Gene therapy (D) involves the introduction of genes into a patient to treat a genetic disorder and is not necessarily related to transferring genes between organisms. DNA translocation (E) is not a commonly used term in molecular biology and is not specifically related to gene transfer.

Question 8

Restriction enzymes are used in genetic engineering to cut DNA between specific base pairs in a DNA strand, resulting in DNA segments that are then used for further study and analysis.

Accepted Answer

Restriction enzymes recognize specific DNA sequences and cut the DNA at those sites, allowing for targeted manipulation of DNA segments in genetic engineering.

Question 9

Pharmaceutical companies prefer to genetically engineer large animals with human genes because it may be possible to obtain large amounts of the resulting protein from the animals'

Accepted Answer

Large animals such as cows and goats can be genetically engineered to produce human proteins in their milk. This allows for the large-scale production of these proteins, which can be used for various medical purposes. The other options listed (fur, blood, meat, bones) are not typically used for pharmaceutical production.

Question 10

Which one of the following is an example of "gene pharming"?

Accepted Answer

Gene pharming involves the use of genetically engineered animals or plants to produce pharmaceuticals. Option C is an example of gene pharming because the goat has been genetically engineered to produce human antithrombin III protein in its milk. The other options do not involve the use of genetically engineered animals or plants for pharmaceutical production. A involves the use of bacteria to produce human insulin, B involves the genetic modification of rice to produce beta-carotene, and D involves the use of yeast to produce HBV vaccines.

Question 11

Plasmid DNA from humans has been successfully inserted and expressed in bacteria.

Accepted Answer

The answer of Plasmid DNA from humans has been successfully...

Question 12

The first successful treatment of a human genetic disorder through gene therapy was with a disorder known as

Accepted Answer

The first successful treatment of a human genetic disorder through gene therapy was with severe combined immunodeficiency disease (SCID), also known as "bubble boy" disease. In 1990, a four-year-old boy named Ashanti DeSilva with SCID who had failed other treatments received gene therapy, which resulted in the production of T cells and a corrected immune system. This marked the first successful use of gene therapy in humans.

Question 13

Which one of the following genetically engineered vaccines is presently on the market?

Accepted Answer

The vaccine for hepatitis B has been genetically engineered and is currently on the market. Vaccines for HIV, malaria, influenza, and human papillomavirus have been developed using genetic engineering techniques, but they are not yet on the market or are in limited use.

Question 14

Which one of the following explanations does not describe why generating transgenic animals is more difficult than plants?

Accepted Answer

While genetic material can be introduced to animal cells in culture media, transgenic animals cannot simply be grown in culture media like plants. Instead, genetic material must be inserted into a fertilized egg, then implanted into a living animal, making the process more difficult and complex compared to generating transgenic plants.

Question 15

Which one of the following is a problem associated with traditional vaccines as opposed to vaccines produced by transgenic organisms?

Accepted Answer

Traditional vaccines often contain killed or weakened pathogens to stimulate an immune response, which can sometimes result in symptoms of the disease. Vaccines produced by transgenic organisms, however, often use specific protein or genetic components of the pathogen, which reduces the risk of experiencing disease symptoms.

Question 16

One of the main problems associated with treating human diseases through gene therapy is

Accepted Answer

One of the main problems associated with treating human diseases through gene therapy is finding a delivery system that would target specific cell types. Gene therapy delivery systems must be designed to specifically target the cells affected by the disease without causing harm to other cells.

Question 17

Through genetic engineering, it is possible for scientists to identify the sequence of bases in DNA, determine the location of certain genes in DNA, and create more DNA from DNA samples.

Accepted Answer

Genetic engineering techniques such as DNA sequencing, gene mapping, and DNA cloning allow scientists to identify the sequence of bases in DNA, locate specific genes within DNA, and replicate DNA samples.

Question 18

Which one of the following human proteins, produced by transgenic bacteria, is used to prevent or break down blood clots?

Accepted Answer

Tissue plasminogen activator (TPA) is a human protein that is produced by transgenic bacteria and is used to prevent or break down blood clots. Insulin is used to regulate blood sugar levels in diabetes, erythropoietin stimulates the production of red blood cells, growth hormone stimulates growth and development, and factor VIII is used in the treatment of hemophilia A.

Question 19

The first successful treatment of a genetic disorder by gene therapy was the curing of a 4-year-old girl who had severe combined immunodeficiency disease. Because the engineered cells do not live forever, this child must supplement her treatment with regular doses of

Accepted Answer

The genetic disorder mentioned in the passage is severe combined immunodeficiency disease, which is caused by a deficiency in the enzyme adenosine deaminase. The first successful gene therapy involved the insertion of a functional copy of the adenosine deaminase gene into the patient's cells. Therefore, the child must supplement her treatment with regular doses of adenosine deaminase.

Question 20

Small pieces of DNA can be amplified by a process known as polymerase chain reaction.

Accepted Answer

Polymerase chain reaction (PCR) is a widely used technique for amplifying small fragments of DNA. It involves making many copies of a specific DNA sequence using a DNA polymerase enzyme and a set of primers that flank the target sequence. PCR has numerous applications in research, medicine, and forensics.

Quiz 20: DNA Technology and Genetic Engineering