Question 1

What is used to cut DNA in generating recombinant DNA?

Accepted Answer

Restriction enzymes are used to cut DNA in generating recombinant DNA. These enzymes recognize specific DNA sequences and cleave the phosphodiester bonds between nucleotides at those sites, allowing for the insertion of foreign DNA.

Question 2

Tobacco plants have had a gene from fireflies inserted into them which makes them glow. These tobacco plants would be considered:

Accepted Answer

The tobacco plants with the firefly gene inserted into them are considered transgenic organisms because they have genetic material from multiple species. Mutants would refer to plants with naturally occurring genetic mutations, clones are genetically identical copies of the same plant, and vectors are typically used to transfer genetic material between organisms.

Question 3

Which choice is an example of "recombinant DNA"?

Accepted Answer

Recombinant DNA involves combining DNA from different sources. In this case, the bacterial plasmid and the human gene are from two different sources and have been combined, making it an example of recombinant DNA.

Question 4

What is the function of restriction enzymes in bacteria?

Accepted Answer

Restriction enzymes are used by bacteria to cut foreign DNA, providing a defense mechanism against invading viruses. This allows the bacterial cell to break down and eliminate the foreign DNA.

Question 5

Which statement is a characteristic of plasmids?

Accepted Answer

Plasmids are small, circular, double-stranded DNA molecules that can replicate independently of the bacterial chromosome. This property makes them useful for creating recombinant DNA by inserting specific genes into the plasmid and then introducing the plasmid into bacteria. Plasmids are relatively easy to manipulate and can be used as vectors for gene cloning and expression.

Question 6

If a restriction enzyme leaves a sticky end on a DNA fragment, it means the fragment:

Accepted Answer

A restriction enzyme can create a sticky end on a DNA fragment by cutting the phosphodiester bond between two nucleotides in a staggered manner, leaving a protruding end of a small number of unpaired bases. These unpaired bases can hydrogen bond with complementary single-stranded DNA and facilitate the joining of two fragments through ligation. The sticky ends are not specific to any organism, and the DNA fragment still needs a cloning vector to transform bacteria.

Question 7

The restriction enzyme EcoRI cuts between the G and the A of the sequence GAATTC. Which statement is true about this enzyme?

Accepted Answer

The EcoRI restriction enzyme cuts the sequence GAATTC and leaves sticky ends of sequence AATT. This applies to both bacterial and bacteriophage DNA, not just one or the other.

Question 8

One advantage of using bacteria in recombinant DNA technology is that they have a ring of DNA that is not part of their chromosome called a:

Accepted Answer

Bacteria possess plasmids which are circular DNA molecules, separate from the chromosomal DNA, and can replicate independently. Plasmids can be easily manipulated in the laboratory and are commonly used as vectors for gene cloning and expression in recombinant DNA technology.

Question 9

What is one of the advantages of producing human growth hormone (HGH) from a cloned gene in a bacterial cell?

Accepted Answer

Producing HGH from a cloned gene in a bacterial cell allows for larger quantities of the hormone to be produced than would be possible from human sources. This is because bacteria can be easily grown in large quantities in fermentation tanks, whereas isolating HGH from human tissue sources would be a more complex and limited process.

Question 10

What is a "cloning vector"?

Accepted Answer

A cloning vector is a DNA molecule that serves as a vehicle to carry foreign DNA into a host cell where it can be replicated and expressed. This vehicle can be a plasmid or a viral genome that has been genetically modified to include the desired gene or DNA fragment. Once the DNA has been inserted into the cloning vector, it can be introduced into a host cell, usually bacterial or yeast, where it will be replicated along with the host's DNA.

Question 11

What roles do plasmids play in biotechnology?

Accepted Answer

Plasmids are often used in biotechnology as vectors for transferring genes between organisms. They can be modified to carry specific genes of interest and then introduced into target cells, where they can replicate and express those genes. This is a common technique used in genetic engineering and the production of recombinant DNA.

Question 12

What property of restriction enzymes allows DNA from different organisms to be combined?

Accepted Answer

If the same restriction enzyme cuts two different DNAs, the ends are complementary. This means that the ends of the cut DNA sequences will have the same overhanging or sticky ends, allowing them to fit together like puzzle pieces when mixed. This property is essential for combining DNA from different organisms using restriction enzymes.

Question 13

It is beneficial for children in underdeveloped countries to eat genetically modified "golden rice," rather than regular rice, because golden rice:

Accepted Answer

Golden rice is genetically modified to produce beta-carotene, a precursor to vitamin A, which is lacking in the diets of many children in underdeveloped countries. Vitamin A deficiency can lead to blindness, so consuming golden rice can be beneficial in preventing this problem. The other choices are not relevant to the benefits of golden rice.

Question 14

Restriction enzymes are mainly derived from:

Accepted Answer

Restriction enzymes are mainly derived from bacteria, specifically from their immune system to defend against foreign DNA.

Question 15

Biotechnology can be defined as the:

Accepted Answer

Biotechnology refers to the use of technology to control biological processes in order to meet societal needs. While the other options involve the use of technology and biology, they do not accurately define biotechnology.

Question 16

"Golden rice" is a transgenic form of rice because it:

Accepted Answer

"Golden rice" contains two foreign genes, one from a bacterium and one from a daffodil, which allows it to produce beta-carotene, a precursor to vitamin A.

Question 17

"Bacterial transformation" is a bacterium's ability to:

Accepted Answer

Bacterial transformation refers to a bacterium's ability to take up DNA from its surroundings, which can potentially alter its genetic makeup. This process is frequently used in genetic engineering, where foreign DNA is introduced into bacteria in order to produce desired proteins or other products. Therefore, choice A is the best answer as it describes the central process of bacterial transformation. The other choices (B, C, and D) do not accurately describe bacterial transformation.

Question 18

Much of the food crops in the United States are transgenic. This primarily has been done to give the crops what properties?

Accepted Answer

The primary reason for genetically modifying food crops in the United States is to give them the ability to resist insects and herbicides. This is done through genetic engineering that inserts genes from other organisms to create desirable traits, such as insect and herbicide resistance. This allows for greater crop yields and reduces the need for harmful pesticides and herbicides, making farming more environmentally sustainable.

Question 19

What is the most common way of introducing recombinant DNA into bacterial cells?

Accepted Answer

Transformation is the most common way of introducing recombinant DNA into bacterial cells. This process involves treating cells with calcium or heat shock, which increases the permeability of the bacterial membrane and allows for the uptake of foreign DNA. Viral vectors are typically used for introducing recombinant DNA into eukaryotic cells, and PCR is a technique used for making multiple copies of a specific DNA sequence. Gel electrophoresis is a technique used to separate and visualize DNA molecules based on size.

Question 20

Why are restriction enzymes that produce sticky ends valuable?

Accepted Answer

Sticky ends have overhanging sequences that can hydrogen bond with complementary sequences of DNA from any source, making them valuable for DNA cloning and recombination experiments.

Quiz 15: The Future Isnt What It Used to Be: Biotechnology