Chapter 22: Biotechnology

What is a gene knockout? Is an animal or plant with a gene knockout a heterozygote or homozygote? What might you conclude if a gene knockout does not have a phenotypic effect?

A gene knockout is when one of an organism's genes is made inoperative. An animal with a gene knockout is a homozygote. If the gene knockout does not have a phenotypic effect we can conclude that: (1) the gene may only make a small contribution to an organism's phenotype, (2) it may involve a gene redundancy, where one type of gene is inactivated and another gene with a similar function may be able to compensate for the inactive gene, or (3) the effects of the knockout may be observed only under certain types of environmental conditions.

Which of the following was the first living organism to be patented? a. A strain of E. coli that makes somatostatin b. A strain of E. coli that makes insulin c. An oil-eating bacterium d. A strain of B. thuringiensis that makes an insecticide

A. A strain of E. coli that makes somatostatin

What is a recombinant microorganism?

An organism that contains a different combination of alleles than its parents.

What is a transgenic organism?

An organism that has received genetic material from another species

Which one of the following is the correct function of factor VIII? A. Simulate production of red blood cells B. Blood clotting factor C. Antioxidant D. Promotes glucose uptake by cells E. Lowers blood pressure

B. Blood clotting factor

Which one of the following statements was not presented as a viable explanation why a gene knockout produces no obvious phenotypic effect? A. The gene has a relatively minor/insignificant contribution to phenotype B. Dosage compensation C. Environmental conditions weren't such that the effects of the knockout would be observed. D. Gene redundancy

B. Dosage compensation

What is the specific function of the kanamycin in the T-DNA vector system of creating transgenic plants? A. Kills transformed plant cells B. Kills non-transformed plant cells C. Kills the A. tumefaciens cells that didn't receive the vector D. Kills that A. tumefaciens cells that received the vector

B. Kills non-transformed plant cells

What is the general function of Bt genes that are introduced into transgenic plants? A. Produce proteins that increase the rate of photosynthesis B. Produce toxins to kill insects C. Produce toxins to kill bacteriophage D. Produce proteins that increase starch storage

B. Produce toxins to kill insects

One strategy for producing a protein in the milk of a cow is to place the coding sequence of the gene of interest next to a __________ and then inject the gene into a _________. a. lac operon promoter, cow oocyte b. β-lactoglobulin promoter, cow oocyte c. lac operon promoter, cow mammary cell d. β-lactoglobulin promoter, cow mammary cell

B. β-lactoglobulin promoter, cow oocyte

Which one of the following could be used to treat anemia? A. TPA B. Factor VIII C. Erythropoietin D. Insulin

C. Erythropoetin

What was the intended long-term goal in creating GloFish? A. To produce an interesting pet for aquariums B. To produce recombinant pharmaceuticals C. To detect water pollution D. To detect the presence of certain aquatic microorganisms E. To introduce the GFP gene into native fish species.

C. To detect water pollution

In the experiments to create recombinant insulin, what was used (1 or 2 words) to cleave the fusion protein expressed in bacteria?

CNBr

In the procedure in Figure 22.1, why was it necessary to link the coding sequence for the A or B chains to the sequence for β-galactosidase? How were the A or B chains separated from β-galactosidase after the fusion protein was synthesized in E. coli?

Creating a fusion protein of beta-galactosidase and the A or B chain is necessary because the A and B chains rapidly degrade. The chains are separated by CNBr, which cleaves the fusion protein after a methionine that is found at the junction between beta-galactosidase and the A or B chain.

A gene "knockin" is most closely associated with: A. Silencing B. Modification C. Deletion D. Addition

D. Addition

Which one of the following is the correct function of insulin? A. Simulate production of red blood cells B. Blood clotting factor C. Antioxidant D. Promotes glucose uptake by cells E. Lowers blood pressure

D. Promotes glucose uptake by cells

True or False: A crown gall tumor forms with the use of T-DNA vectors.

False

True or False: The same phenomenon observed in Dolly's chromosomes has been observed in mice and cattle cloning experiments.

False

What genetic event (2 words) did we study in chapter 20.1 knockin that is used to accomplish the knockin?

Homologous recombination

In the study of plants and animals, it is relatively common for researchers to identify a gene using molecular techniques without knowing the function of the gene. In the case of mice, the function of the gene can be investigated by making a gene knockout. A knockout that causes a phenotypic change in the mouse may provide an important clue regarding the function of a gene. For example, a gene knockout that produced an albino mouse would indicate that the knocked-out gene probably plays a role in pigment formation. The experimental strategy of first identifying a gene based on its molecular properties and then investigating its function by making a knockout is called reverse genetics. Explain how this approach is opposite to (or the reverse of) the conventional way that geneticists study the function of genes.

In Mendel's work, and the work of many classical geneticists, an altered (mutant) phenotype is the initial way to identify a gene. For example, Mendel recognized a gene that affects plant height by the identification of tall and dwarf plants. The transmission of this gene could be followed in genetic crosses, and eventually, the gene could be cloned using molecular techniques. Reverse genetics uses the opposite sequence of steps. The gene is cloned first, and a phenotype for the gene is discovered later, by making a transgenic animal with a gene knockout.

In the case of molecular pharming, what is the most commonly used product from which to isolate the recombinant protein (one word)?

Milk

What is reproductive cloning? Are identical twins in humans considered to be clones?

Reproductive cloning is a method used to produce two or more genetically identical individuals. Technically, yes, twins are considered to be clones. This is a natural occurrence in nature.

What segment of DNA from the Ti plasmid is naturally tranferred from the bacterium to the infected plant cell?

T DNA

Recombinant bacteria can produce hormones that are normally produced in humans. Briefly describe how this is accomplished.

The human gene that encodes the hormone is manipulated in vitro and then transformed into a bacterium. In many cases, the coding sequence of the human hormone gene is fused with a bacterial gene to prevent the rapid degradation of the human hormone. The bacteria then express the fusion protein and the hormone is separated by cyanogen bromide.

What is molecular pharming? Compared with the production of proteins by bacteria, why might it be advantageous?

The term molecular pharming refers to the practice of making transgenic animals that will synthesize human products in their milk. It also refers to the manufacture of medical products by agricultural plants. It can be advantageous when bacterial cells are unable to make a functional protein product from a human gene.

As shown in Table 22.2, several medical agents are now commercially produced by genetically engineered microorganisms. Discuss the advantages and disadvantages of making these agents this way.

These medicines are difficult and expensive to purify from human sources. The advantage of genetically engineered organisms is they can produce a large amount of these medical agents at a fraction of the cost. There are some disadvantages. For example, a medical agent may require posttranslational modifications that do not occur in microorganisms. Public perception of genetic engineering may also be a problem, although it has usually not been a big problem in this particular area of genetic engineering.

True or False: All transgenics are GMOs but all not all GMOs are transgenic.

True

True or False: An ES cell is pluripotent.

True

True or False: Plant somatic cells are totipotent.

True

When a cloned gene is inserted into a noncritical site in the mouse genome by homologous recombination, the result is a. gene addition. b. gene modification. c. gene knockout. d. both a and b

a. gene addition

Which method (three words) of creating transgenic plant cells relies on the use of a "gene gun"?

biolistic gene transfer

During mammalian reproductive cloning, _________ is fused with __________. a. a somatic cell, a stem cell b. a somatic cell, an egg cell c. a somatic cell, an enucleated egg cell d. an enucleated somatic cell, an egg cell

c. a somatic cell, an enucleated egg cell

What plant cell component (2 words) creates a natural barrier to DNA entry?

cell wall

What two crops (one word each) have been widely manipulated using the Bt transgene?

corn; cotton

Which of the following uses of microorganisms is/are important in biotechnology? a. Production of medicines b. Food fermentation c. Biological control d. All of the above

d. All of the above Microorganisms are useful in the production of medicines, such as insulin. They aid in food fermentation, such as our beloved cheese, and microorganisms can be used as a biological control agent to help decrease pollutants in the environment.

What is the key reason why the A and B chains of insulin are made as fusion proteins with β-galactosidase? a. To make purification easier b. To prevent their degradation c. To be secreted from the cell d. All of the above are reasons for making the chains as fusion proteins

d. All of the above are reasons for making the chains as fusion proteins.

Which of the following is a key feature of stem cells? a. They have the ability to divide. b. They have the ability to differentiate. c. They are always pluripotent. d. Both a and b are true of stem cells.

d. Both a and b are true of stem cells. They have the ability to divide and differentiate into one or more specialized cells.

In the knockin proceedure, the regions of DNA that flank the cloned gene are ___________ (one word) to the sequences of the noncritical site.

homologous

What two antibiotics (one word each) are typically used in association with T-DNA vectors?

kanamycin; carbenicillin

A cell from what type of tissue (one word) was used as the source of the nucleus to produce Dolly?

mammary

The length of what part of the Dolly's chromosomes (one word) seemed to reflect premature aging from a genetic perspective?

telomeres

Typically, cloning is classified on the basis of its intended outcome. The two types of cloning are reproductive and __________

therapeutic

What one-word term is used to describe stem cells that possess all developmental options?

totipotent

What one-word term is used to describe stem cells that possess only one developmental option?

unipotent