biol101 ch22

Biotechnology is broadly defined as the use of living organisms, or their products, to achieve what purpose?

To benefit humans.

Approximately when did biotechnology begin through the domestication of plants and animals?

12,000 years ago.

What is the specific term for an organism that has integrated recombinant DNA into its genome?

Transgenic.

Which specific technology has allowed molecular genetics to improve the use of organisms since the 1970s?

Recombinant DNA technology.

According to Table 22.1, which microorganism is used to synthesize human insulin?

Recombinant $E. coli$.

In the context of biological control, how do nonpathogenic microorganisms prevent plant disease?

By competing effectively against pathogens for nutrients or space.

What antibiotic produced by $Agrobacterium radiobacter$ is used to prevent crown gall disease?

Agrocin 84.

Why were researchers forced to find $A. radiobacter$ strains with conjugation-deficient plasmids for commercial use?

To prevent the transfer of synthesis and resistance genes to the pathogen via conjugation.

What is the primary physiological mechanism by which $Bacillus thuringiensis$ (Bt) toxins kill caterpillars and beetles?

The toxins paralyze the insect's digestive tract.

The use of microbial enzymes to transform the structure of toxic pollutants is known as _____.

Biotransformation.

How does biodegradation differ from general biotransformation in bioremediation?

Biodegradation specifically results in the breakdown of toxic pollutants into nontoxic metabolites.

Which pharmaceutical agent produced by recombinant microorganisms is used to dissolve blood clots during heart attacks?

Tissue plasminogen activator (TPA).

What medical condition is treated using Erythropoietin produced by recombinant microorganisms?

Anemia (by stimulating the production of red blood cells).

Insulin regulates glucose uptake specifically into which two types of human cells?

Fat cells and muscle cells.

What specific cells in the pancreas are defective in individuals with insulin-dependent diabetes?

$\beta$ cells.

In biotechnology logic, what is the fundamental difference between gene addition and gene modification?

Gene addition involves inserting a cloned gene into a genome, while gene modification alters the existing sequence of a gene.

What is a 'gene knockin' in the context of mouse models?

A gene of interest is inserted into a particular site in the mouse genome.

Xenotransplantation involves using tissues or organs from _____.

Different species.

Why are the surface molecules of pig cells often altered when engineering animal models for human transplantation?

To make the cells less immunogenic and reduce the chance of immunorejection.

Which human protein produced in cow milk is used as an iron supplement in infant formula?

Lactoferrin.

For what medical purpose is human $\alpha1$-Antitrypsin produced in the milk of transgenic sheep?

Treatment of emphysema.

In the protocol for expressing human genes in animal milk, where must the human gene be inserted in the plasmid vector?

Next to a milk-specific promoter.

What is the specific role of the $\beta$-lactoglobulin promoter in the production of transgenic sheep milk?

It ensures the gene is functional only in mammary cells so the protein is secreted into the milk.

In Reproductive Cloning, why were mammals historically thought to be 'unfit' for cloning from somatic cells?

It was believed that somatic cells underwent irreversible genetic changes.

What was the landmark year for the first successful cloning of a mammal (Dolly the sheep)?

1997

Identify the two types of cells fused via electrical pulses to create the embryo that became Dolly.

A diploid mammary cell and an enucleated oocyte.

The Data Decoder: At 3 years of age, Dolly's telomeres were consistent with a sheep of what age range?

9 to 10 years old.

What was the likely cause of the premature shortening of Dolly's telomeres?

The telomeres were already shortened in the 6-year-old donor sheep from which the somatic cell was taken.

Microarray studies of cloned mice revealed that what percentage of genes were not expressed normally?

4%.

How did the telomere results of cloned mice and cattle produced after Dolly compare to her specific telomere data?

The telomeres in cloned mice and cattle appeared to be the correct length.

What is a significant agricultural disadvantage of maintaining a genetically homogeneous herd of livestock?

The herd may be more susceptible to rare diseases.

Transgenic plants expressing pokeweed antiviral protein demonstrate resistance to _____.

Viral pathogens.

Why is the production of transgenic plants considered easier than transgenic animals?

Some somatic plant cells are totipotent, allowing an entire organism to be regenerated from a single cell.

What does the 'Ti' in Agrobacterium's Ti plasmid stand for?

Tumor-inducing.

When modifying a Ti plasmid for use as a transgenic vector, which specific genes are deleted to ensure plant safety?

The genes that cause gall tumors.

What is the function of the $kan^R$ gene in the production of transgenic plants via T-DNA vectors?

It serves as a selectable marker by conferring kanamycin resistance.

During T-DNA mediated gene transfer, which antibiotic is used to specifically kill $A. tumefaciens$ cells after infection?

Carbenicillin.

Besides $Agrobacterium$ infection, what is the second most common method for producing transgenic plants?

Biolistic gene transfer (using a 'DNA gun').

In biolistic gene transfer, the 'microprojectiles' shot into the plant cells are coated with _____.

DNA.

Which gene therapy method involves the use of liposomes to deliver DNA into target cells?

The nonviral approach.

What are the three most common types of viruses used as vectors in the viral approach to gene therapy?

Retroviruses, adenoviruses, and parvoviruses.

Severe Combined Immunodeficiency (SCID) can be caused by a defect in which enzyme involved in purine metabolism?

Adenosine deaminase (ADA).

Why is a deficiency in Adenosine deaminase (ADA) fatal to the immune system?

Deoxyadenosine accumulates and is toxic to B and T cells.

In the first human gene therapy trial for ADA-SCID, what type of cells were removed from the patient to be transfected?

Lymphocytes.

During the ADA-SCID gene therapy protocol, how does the retrovirus ensure the normal ADA gene is passed on during cell division?

The retrovirus inserts its DNA into the host cell chromosome.

Interpreting the Data: Why were the initial results of the first human ADA gene therapy considered 'not conclusive'?

The ADA gene was expressed in only a small percentage of cells, and drug treatment was still needed.

What severe complication arose in clinical trials for SCID caused by a mutant $\gamma_c$ cytokine receptor?

Patients developed leukemia.

Troubleshooting: What molecular event caused leukemia in gene therapy patients treated for the mutant $\gamma_c$ receptor?

The retroviral vector integrated into the host genome next to a particular gene that triggered uncontrolled growth.

What process involves using microscopic-sized needles to inject DNA directly into a cell?

Microinjection.

In bioremediation, what is the term for the degradation of toxic pollutants into nontoxic metabolites?

Biodegradation.

Which hormone produced by $\beta$ cells is synthesized by recombinant $E. coli$ to treat diabetes?

Insulin.

According to the graph of Bt usage since 1996, which crop generally shows a higher percentage of Bt-integrated acreage: corn or cotton?

Bt cotton.

In the 'viral approach' to gene therapy, what must happen to the viral RNA genome after it is released into the cytosol?

It must be reverse-transcribed into DNA.

Which antioxidant agent is produced by recombinant microorganisms to minimize tissue damage after heart attacks?

Superoxide dismutase.

What is the primary treatment for hemophilia types caused by Factor VIII or Factor IX deficiency?

Recombinant Factor VIII or Factor IX replacement therapy.

Under what condition is a DNA-liposome complex taken into a target cell during gene therapy?

Endocytosis.

What happens to a liposome once it is inside the endosome of a target cell?

The liposome is degraded, and the DNA is released into the cytosol.

The production of a crown gall tumor by $A. tumefaciens$ is driven by genes located within the _____.

T-DNA.

In the T-DNA vector method, why are both carbenicillin and kanamycin added to the medium during selection?

To kill $A. tumefaciens$ cells and plant cells that have not taken up the T-DNA, respectively.

What is the specific host used to produce human Factor IX for the treatment of hemophilia in milk?

Sheep.

Why is the use of recombinant microorganisms considered a field with high negative public perception?

Safety concerns regarding the release of genetically modified organisms into the environment.

In the context of SCID, what is the consequence of deoxyadenosine toxicity on purine metabolism?

The destruction of B and T cells.

Which method of ADA deficiency treatment involves coupling the enzyme to polyethylene glycol (PEG)?

Purified ADA injection therapy.

The first human gene therapy clinical trial for ADA deficiency was approved in what year?

1990

Which transgenic animal overexpressing growth hormone is shown in Figure 22.2?

Salmon.

What was the name of the first cloned pet, introduced in 2002?

Carbon Copy (also called Copy Cat).

In plant biotechnology, the ability to regenerate an entire plant from a single somatic cell is known as _____.

Totipotency.

The synthesis of antibodies to combat specific infectious diseases has been successfully achieved in the milk of which host animal?

Cattle.

Which gene therapy vector is notorious for causing leukemia due to its integration site in some SCID trials?

Retroviral vector.

What are the three main approaches currently used to treat Adenosine deaminase (ADA) deficiency?

Bone marrow transplant, PEG-ADA injections, and gene therapy.