Application of techniques

What is a genetically modified organism (GMO)?

An organism that has had its genome altered by the addition of a gene or genes from another organism.

What is a transgenic organism (TGO)?

An organism that has had its genome altered by the addition of a gene or genes from another organism of a different species.

Give an example of a transgenic organism.

Glofish® are transgenic organisms because their genome includes genes from jellyfish, coral, or sea anemones that code for fluorescent proteins.

What is the pGLO plasmid?

An engineered plasmid that contains the GFP gene from Aequorea victoria and the gene for Beta-lactamase, which digests ampicillin.

What is the function of green fluorescent protein (GFP)?

GFP glows with bright green fluorescence under ultraviolet light and is used as a reporter to detect gene expression in transgenic organisms.

How does AraC regulate gene expression in the pGLO plasmid?

The AraC repressor protein blocks transcription of the GFP gene when arabinose is absent, but allows transcription when arabinose is present.

What is the role of arabinose in the pGLO system?

Arabinose binds to the AraC repressor protein, altering its shape to allow transcription of the GFP gene.

What is the purpose of using plasmids as vectors in genetic engineering?

Plasmids carry target genes into bacterial cells, allowing those cells to express the added genes and produce specific proteins.

What is the significance of antibiotic-resistance genes in plasmids?

They allow for the easy identification of bacterial cells that contain the recombinant plasmid.

How is human insulin produced using recombinant DNA technology?

By creating recombinant plasmids that carry the insulin genes and transforming bacterial cells to produce insulin.

What are the two strains of bacteria used in insulin production?

One strain carries the plasmid with the Insulin A gene, and the other carries the plasmid with the Insulin B gene.

What is cDNA and how is it produced?

cDNA is complementary DNA made from mature mRNA using reverse transcriptase, followed by amplification with PCR.

What is the process for creating recombinant DNA?

The target gene is cut with a restriction enzyme, the plasmid is cut with the same enzyme, and the gene is inserted into the plasmid.

What role does DNA ligase play in recombinant DNA technology?

DNA ligase re-joins the sugar-phosphate backbone of the DNA after the target gene is inserted into the plasmid.

What are regulatory genes and how do they function?

Regulatory genes control the timing of expression of target genes and can be activated by inducers like sugars or metal ions.

What are the methods used to transform bacterial cells?

Heat shock and electroporation are methods used to induce the uptake of recombinant plasmids by bacterial cells.

What is the purpose of selection and screening in recombinant DNA technology?

To identify bacterial cells that have successfully taken up the recombinant plasmids containing the target gene.

Why is it important to isolate mature mRNA when producing cDNA?

Mature mRNA lacks introns, ensuring that the cDNA produced will only contain the coding sequences needed for protein production.

What happens if a plasmid closes without accepting the target gene?

The plasmid will not produce the desired protein, and only transformed cells with the target gene will be capable of producing it.

What is the significance of having multiple copies of plasmids in a bacterial cell?

It increases the likelihood of producing the desired protein, as one cell can replicate several copies of the plasmid.

What is the role of the Beta-lactamase gene in the pGLO plasmid?

It provides resistance to the antibiotic ampicillin, allowing for the selection of transformed bacteria.

How do restriction enzymes facilitate gene cloning?

They cut DNA at specific sequences, allowing for the insertion of target genes into plasmids.

What is the relationship between insulin A and insulin B in human insulin production?

Both A and B subunits are required for functional insulin, and they are produced separately before being combined.

What is the purpose of PCR in the context of cDNA?

PCR is used to amplify the cDNA, producing many copies for further use in cloning or expression.

What does the term 'transformed' refer to in bacterial cells?

It refers to bacterial cells that have successfully taken up recombinant plasmids.

What is the significance of using a sticky-end restriction enzyme?

Sticky ends allow for easier ligation of the target gene into the plasmid due to complementary base pairing.

What gene allows for the screening of transformed bacteria?

A gene for antibiotic resistance, such as ampR for ampicillin resistance.

What happens to non-transformed bacteria on ampicillin agar?

They do not survive.

What color do colonies of transformed bacteria appear when using X-gal?

White, because they cannot produce β-galactosidase.

What is the function of the lacZ gene in plasmid transformation?

It produces β-galactosidase, which digests X-gal to produce a blue product.

What is one application of transforming bacteria with the INS gene?

To produce human insulin.

Name a protein that can be synthesized using recombinant DNA technology for cancer therapy.

Interleukin-2.

What is the purpose of creating transgenic plants?

To increase crop productivity and provide resistance to disease.

What is the role of Agrobacterium tumefaciens in making transgenic plants?

It transfers desired genes into plant cells' DNA.

What is one benefit of herbicide-resistant canola?

It allows herbicide use for weed control without killing canola plants.

How does salt-tolerant wheat improve agricultural productivity?

It increases the land area that can be used for growing wheat.

What does Bt cotton produce to protect against insect predation?

Insecticidal proteins that damage the digestive systems of pests.

What is a concern regarding the use of Bt crops?

Potential effects on non-target species, such as monarch butterflies.

What ethical principle focuses on maximizing benefits and minimizing risks?

Beneficence.

What does the principle of non-maleficence entail?

Avoiding the causation of harm.

What ethical concept ensures fair distribution of benefits?

Justice.

What are the three approaches to bioethics?

Consequences-based, duty-based, and virtues-based approaches.

What is the consequence-based approach in bioethics?

It focuses on maximizing positive outcomes and minimizing negative outcomes.

What does the duty-based approach emphasize?

Following ethical rules, regardless of the consequences.

What is the virtues-based approach in bioethics concerned with?

The moral character and behaviors a good person would seek to achieve.

What is the significance of the INS gene in recombinant DNA technology?

It allows for the production of human insulin in transformed bacteria.

What are some examples of proteins that can be synthesized through recombinant DNA technology?

Epidermal growth factor, antibodies for immunotherapy, and enzymes for food processing.

What ethical implications arise from the development of GM canola?

Concerns about the relationship between the company producing GM canola and the herbicide it sells.

What is the role of the salt-tolerant gene in wheat?

It codes for a protein that removes sodium from leaves, allowing normal water transport.

What is the impact of Bt cotton on pesticide use?

It reduces the need for sprayed pesticides, decreasing environmental impact.

What is a potential risk of transgenic crops?

They could cause allergies in individuals sensitive to certain proteins.