Genetic Engineering

Question 1

What is genetic engineering?

Answer 1

The artificial manipulation and alteration of genes.

Question 2

What was the first organism to be genetically modified?

Answer 2

An E. coli bacterium.

Question 3

What was the first animal to be genetically modified?

Answer 3

A mouse.

Question 4

How many steps are involved in genetic engineering?

Answer 4

5.

Question 5

What is the first step of genetic engineering?

Answer 5

Isolation

Question 6

What is isolation?

Answer 6

Isolation is the process of removing DNA from a cell.

Question 7

(2 points)

How is DNA isolated from cells?

Answer 7

• DNA is isolated from cells by splitting the cells open using a mild detergent and gentle agitation.
• Protease are also added to remove proteins (histones) associated with the DNA.

Question 8

What is the second step of genetic engineering?

Answer 8

Cutting and ligation

Question 9

What is cutting?

Answer 9

The removal of a gene of interest from a piece of DNA using restriction enzymes.

Question 10

(4 points)

How does the process of cutting occur?

Answer 10

• Cutting is carried out by restriction enzymes.
• Restriction enzymes will act only on a particular sequence of DNA and cut it open only at that site.
• Once the gene of interest has been cut from its position, it is inserted into another piece of DNA called a vector.
• The same restriciton enzyme that is used to cut out the gene if interest is used to cut open the vector DNA.

Question 11

What is a vector?

Answer 11

A piece of DNA (e.g. a bacterial plasmid) that will carry the gene of interest into a host cell.

Question 12

What vectors are normally used in genetic engineering?

Answer 12

Bacterial plasmids are usually used, but viruses can also be used.

Question 13

(2 points)

What are plasmids?

Answer 13

• Plasmids are circular pieces of DNA that most bacteria possess in addition to their normal DNA.
• This extra piece of DNA contains number of additional genes that usually give the bacteria an adaptive advantage, such as an ability to tolerate the presence of antibiotics.

Question 14

What can a host cell be?

Answer 14

A host cell can be another bacterium or a eukaryotic cell, such as animal or plant cells.

Question 15

What is ligation?

Answer 15

The joining of a gene to a vector using DNA ligase.

Question 16

(2 points)

What is the name of the new piece of DNA as a result of cutting and ligation, and what is it a combination of?

Answer 16

• The new piece of DNA is called recombinant DNA.
• The new piece of DNA is a combination of the desired gene and a plasmid of piece of viral DNA.

Question 17

What is recombinant DNA?

Answer 17

A piece of genetically modified DNA that contains DNA from two or more different species.

Question 18

What is the third step of genetic engineering?

Answer 18

Transformation/Transfection/Transduction.

Question 19

What is transformation?

Answer 19

The uptake of recombinant DNA into a bacterial cell.

Question 20

What is transfection?

Answer 20

Refers to the process of eukaryotic cells, such as animal and plant cells, taking up a recombinant bacterial plasmid.

Question 21

What is transduction?

Answer 21

Refers to the process of any cell taking up a recombinant viral vector or piece of viral DNA.

Question 22

What is the fourth step of genetic engineering?

Answer 22

Selection and cloning.

Question 23

What is selection?

Answer 23

The process of killing any cells that did not take up the recombinant DNA.

Question 24

What percentage of cells usually take up a vector?

Answer 24

Less than 1%.

Question 25

# (3 points) How is selection carried out?

Answer 25

* A vector is usually designed to carry an antibiotic-resistant gene. Any cells that took up the vector will be able to tolerate the presence of an antibiotic. * During the selection process, all cells are exposed to an antibiotic. Only those that were transformed will survive. * The cells containing the gene are then given a number of days to reproduce themselves (cloning).

Question 26

What is cloning?

Answer 26

The process of producing identical copies of a cell.

Question 27

What is the fifth step of genetic engineering?

Answer 27

Expression.

Question 28

# (2 points) What is expression?

Answer 28

* The stimulation of a cell to produce a product of a particular gene. * The product of a gene (a protein) can then be purified if needed.

Question 29

What is one application of genetic engineering in plants?

Answer 29

Corn grown in Spain has been genetically modified to be herbicide and- and insect- resistant. Certain corn strains have also been genetically enhanced to express 168 times the normal amount of vitamin, six times the normal content of vitamin C and twice as much folic acid.

Question 30

What is one application of genetic engineering in animals?

Answer 30

Mosquitoes were genetically modified to be resistant to malaria. This may have significant health benefits for people living in regions where malaria is widespread.

Question 31

What is one application of genetic engineering in microorganisms?

Answer 31

Biotechnology companies have genetically modified certain strains of E. coli bacteria to produce human insulin and human growth hormone. These hormones are then purified and given to patients. The patient's immune system does not react against the hormone because the hormones are human hormones, even though they are produced by bacteria. This is especially important for type 1 diabetics.