chapter 12

Question 1

What is genetic engineering?

Answer 1

The use of in vitro techniques to alter genes in the lab.

Question 2

What is biotechnology?

Answer 2

The use of living organisms for industrial or commercial applications

Question 3

What is molecular cloning?

Answer 3

The isolation and incorporation of a piece of DNA into a vector so it can be replicated and manipulated.

Question 4

What is recombinant DNA?

Answer 4

DNA that has been altered by incorporating genetic material from another organism.

Question 5

What is gel electrophoresis?

Answer 5

A method used to separate DNA, RNA, or proteins based on their size and charge.

Question 6

What is PCR (Polymerase Chain Reaction)

Answer 6

A technique used to amplify a specific segment of DNA, creating millions of copies

Question 7

What is quantitative PCR (qPCR)

Answer 7

A variation of PCR that allows for the measurement of DNA amplification in real-time.

Question 8

What is RT-PCR (Reverse Transcriptase PCR)?

Answer 8

A technique that converts RNA into complementary DNA (cDNA) for amplification and analysis.

Question 9

What is RT-PCR?

Answer 9

A technique to amplify RNA by converting it to cDNA.

Question 10

what does Southern blotting detect?

Answer 10

DNA sequences using hybridization.

Question 11

What is hybridization?

Answer 11

Using probes to pair known sequences with targets in a sample.

Question 12

What is the difference between Taq and Pfu polymerases?

Answer 12

Taq is heat-stable; Pfu is proofreading and corrects errors.

Question 13

What is the first step in molecular cloning?

Answer 13

Isolation and fragmentation of source DNA (genomic DNA, RNA, or PCR fragments).

Question 14

What is used to digest genomic DNA during cloning?

Answer 14

Restriction enzymes.

Question 15

What are cloning vectors typically derived from?

Answer 15

Plasmids or viruses.

Question 16

What enzyme joins DNA fragments in molecular cloning?

Answer 16

DNA ligase.

Question 17

What method is often used to introduce recombinant DNA into a host organism?

Answer 17

Transformation.

Question 18

How is the correct clone detected in molecular cloning?

Answer 18

Using ampicillin resistance and blue/white screening.

Question 19

What do blue colonies indicate in blue/white screening?

Answer 19

The colonies do not have the vector with foreign DNA inserted

Question 20

What do white colonies indicate in blue/white screening?

Answer 20

The colonies have the foreign DNA inserted into the vector

Question 21

What is insertional inactivation in molecular cloning?

Answer 21

The lacZ gene is inactivated by the insertion of foreign DNA

Question 22

Why do inactivated lacZ genes not produce a blue color in colonies?

Answer 22

Inactivated lacZ cannot process Xgal, so the blue color does not develop.

Question 23

What are expression vectors used for

Answer 23

To control the expression of cloned genes.

Question 24

How do expression vectors achieve high levels of protein expression?

Answer 24

By using strong promoters, efficient operators, and effective transcription terminators

Question 25

What is the role of transcription terminators in expression vectors?

Answer 25

To prevent the expression of other genes on the plasmid

Question 26

How are cloned genes controlled in expression vectors using T7 promoter

Answer 26

Cloned genes are placed under control of the T7 promoter and regulated by T7 RNA polymerase.

Question 27

What E. coli strain is used with PET T7 expression vectors for induction by IPTG?

Answer 27

BL21 E. coli strains are designed to work with PET T7 expression vectors.

Question 28

Why does T7 RNA polymerase only transcribe cloned genes?

Answer 28

T7 RNA polymerase only recognizes T7 promoters, so it transcribes only the cloned genes.

Question 29

How does T7 RNA polymerase limit transcription to cloned genes?

Answer 29

T7 RNA polymerase is highly active and uses most RNA precursors, limiting transcription to the cloned genes.

Question 30

What happens to the cells when using T7 RNA polymerase for expression?

Answer 30

Cells stop growing, and translation primarily yields the protein of interest

Question 31

How is genetic engineering used to express eukaryotic genes in prokaryotes?

Answer 31

Genetic engineering allows expression of eukaryotic genes in prokaryotes by cloning the gene via mRNA or finding the gene via the protein

Question 32

What is an example of a eukaryotic gene expressed in bacteria through genetic engineering?

Answer 32

An example is the expression of the insulin gene in bacteria.

Question 33

What are transgenic organisms?

Answer 33

Transgenic organisms (GMOs) are genetically engineered organisms that contain a gene (transgene) from another organism.

Question 34

Where are transgenic organisms commonly used?

Answer 34

Transgenic organisms are commonly used in agriculture and aquaculture

Question 35

What is Agrobacterium tumefaciens used for?

Answer 35

It transfers DNA into plants using the Ti plasmid.

Question 36

What does the Ti plasmid do?

Answer 36

It causes virulence and mobilizes DNA for plant transfer.

Question 37

What is T-DNA?

Answer 37

It's the Ti plasmid segment transferred to plants, with foreign DNA inserted.

Question 38

Why are herbicide- and insect-resistant plants created?

Answer 38

To improve resistance to herbicides, insects, and microbial diseases, and enhance product quality.

Question 39

What are some examples of GM crops?

Answer 39

Soybeans, corn, cotton, canola

Question 40

How are herbicide-resistant plants engineered?

Answer 40

By making crops like soybeans resistant to herbicides like glyphosate (Roundup™).

Question 41

How are plants made resistant to insects?

Answer 41

By inserting the Bt toxin from Bacillus thuringiensis, which is toxic to moth and butterfly larvae

Question 42

What other insects does B. thuringiensis target?

Answer 42

Beetles, flies, and mosquitoes.

Question 43

What is a challenge with Bt-transgenic plants?

Answer 43

Insect resistance to Bt toxin is emerging, such as in rootworms.