Biology - Chp 7, 8, 9

A restriction enzyme:

-is involved in chopping up the DNA from a donor organism. -targets a particular base-pair sequence on either side of the gene. -is usually involved in the first step of biotechnology. -usually recognizes a sequence that is four to eight base pairs long.

When Dolly the sheep was created using whole organism cloning, how many different sheep were involved in the process (excluding Dolly)?

3 (Three sheep were involved in creating Dolly. 1) An egg cell was isolated from one sheep and the nucleus of the cell was removed. 2) A mammary cell was taken from a second sheep, and the nucleus of that cell was implanted into the egg cell. 3) The embryo was transplanted into the uterus of a surrogate mother sheep, and the surrogate ultimately gave birth to Dolly.)

gene library

A collection of cloned DNA fragments; also known as a clone library.

clone library

A collection of cloned DNA fragments; also known as a gene library.

cell-cycle control system

A cyclically operating set of proteins that triggers and coordinates events in the eukaryotic cell cycle.

binary fission

A form of asexual reproduction in which one cell divides to form two identical cells.

cloning

A process in which a cell, cell product, or organism is copied from an original source.

asexual reproduction

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

plasmid

A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome

centrosome

A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. A centrosome has two centrioles.

polymerase chain reaction (PCR)

A technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.

Which of the following is not required to create a DNA fingerprint in a criminal case? A) CRISPR B) the suspect's DNA C) gel electrophoresis D) crime scene DNA E) polymerase chain reaction (PCR)

A) CRISPR (Recall that CRISPR is a gene-editing tool that allows for precise, efficient editing of genes. It would not be useful when creating a DNA fingerprint.)

Which of the following biotechnology tools is incorrectly matched with its purpose? A) restriction enzymes: inhibit DNA overgrowth B) PCR: amplification of DNA into larger quantities C) plasmids: insertion of DNA into a new cell D) cloning: transgenic organism creation E0 All of the above are incorrectly matched.

A) restriction enzymes: inhibit DNA overgrowth (Restriction enzymes cut the DNA into small pieces starting at a specific area of interest.)

Which of the following statements about DNA fingerprinting is true? A) The DNA used cannot possibly produce a banding pattern matching anyone else's. B) The DNA used must be taken from a highly variable region within the genome. C) The DNA used must be taken from a coding region of the genome. D) The DNA used must come from the most conserved (similar) regions of the human genome. E) The DNA used can come from anywhere in the human genome.

B) The DNA used must be taken from a highly variable region within the genome. (Analysis of DNA from a crime scene focuses on the parts of our DNA that differ.)

Which of the examples below is not a potential application of cloning? A) producing cows with increased milk production B) testing embryos for the presence of genes for certain diseases C) cloning tissues to use as grafts to replace damaged tissues D) growing transgenic E. coli containing the gene for human insulin E) producing rhu-EPO in cells, which were originally harvested from hamster ovaries

B) testing embryos for the presence of genes for certain diseases (This would not involve cloning because it would not result in the production of a genetically identical cell, tissue, or organism. See Section 7.9 of your textbook to learn about potential applications of cloning.)

Gene therapy: biotechnology can help diagnose and prevent diseases, but has had limited success in curing them.

Biotech tools have been developed to reduce suffering and reduce the incidence of diseases, but their use comes with potential costs. Gene therapy has had limited success in curing human diseases, primarily because of technical difficulties in transferring normal-functioning genes into the cells of a person with a genetic disease.

Explain how biotechnology can improve food nutrition and make farming more efficient and eco-friendly.

Biotechnology has led to important improvements in agriculture through the use of transgenic plants and animals to produce more nutritious food. Even more significant is the extent to which biotechnology has reduced the environmental and financial costs of producing food through the creation of herbicide-resistant and insect-resistant crops. The potential ecological and health risks of such widespread use of transgenic species are not yet fully understood.

Explain how biotechnology improves the treatment of diseases and production of medicines.

Biotechnology has led to some notable successes in treating diseases, usually by producing medicines more efficiently and effectively than they can be produced with traditional methods.

Which of the following scenarios best illustrates cloning? A) DNA from bacteria is inserted into the genome of soybean plants. B) An organism is produced with recombinant DNA technology. C) A bacterial cell divides, producing a genetically identical copy. D) A plasmid transfers a gene of interest into the genome of a different organism. E) Many identical copies of a fragment of DNA are amplified.

C) A bacterial cell divides, producing a genetically identical copy. (Bacterial cell division produces an exact copy of the original bacterial cell, which is considered a clone.)

Which of the following is not a step of the polymerase chain reaction (PCR)? A) DNA polymerase adds complementary bases to each single strand. B) Two identical copies of the original segment of DNA result. C) A segment of DNA is cooled, which causes it to separate into two single strands. D) Initially, DNA is heated to separate the double-stranded DNA into two single strands. E) DNA polymerase is added to the solution with free nucleotides, and the solution is cooled.

C) A segment of DNA is cooled, which causes it to separate into two single strands. (The DNA strands are actually separated by applying heat.)

Which of the following is the best example of how cloning can currently be used in medicine? A) Severe combined immunodeficiency disease (SCID) can be cured through cloning. B) Human children can be cloned. C) Hamster ovary cells can produce recombinant human erythropoietin. D) Cloning can be used to determine if a person will develop a genetic disease later in life. E) Cloning can be used to screen for the presence of the sickle cell anemia gene.

C) Hamster ovary cells can produce recombinant human erythropoietin. (Transgenic animals containing human genes are an important example of a medical application of cloning.)

Explain how CRISPR has the potential to revolutionize medicine.

CRISPR is a gene (DNA) editing system that brings greater precision and efficiency to gene editing. It is considered a significant breakthrough in biotechnology because the ability to target and snip the DNA of almost any species, at a specific sequence, opens the door to changing an organism's genes in almost any way imaginable.

centriole

Cell organelle that aids in cell division in animal cells only

Explain both opportunities and perils of cloning.

Cloning of individuals has potential benefits in agriculture and medicine, but ethical questions linger.

What are the uses and abuses of DNA fingerprinting?

Comparisons of highly variable DNA regions can be used to identify tissue specimens and determine the individual from whom they came.

Which of the following is not true about gene therapy? A) The organism used to transfer a "good" gene may infect the wrong cells in the recipient. B) Gene therapy has rarely, if ever, produced any clear successful cures. C) Not enough cells in the recipient may get a working copy of the gene. D) In the few cases where gene therapy produced a cure, the children of these patients were free of their parent's disease. E) There is some difficulty in getting a working gene into the specific cells that need it.

D) In the few cases where gene therapy produced a cure, the children of these patients were free of their parent's disease. (Even if gene therapy cures an individual, that person may still pass on the disease-causing genes to his/her children.)

For which of the following are transgenes most commercially utilized in the United States? A) transgenic Atlantic salmon B) rice crops that contain transgenes enabling beta-carotene biosynthesis C) seedless watermelons D) pest- and herbicide-resistant corn, cotton, and soybean crops E) featherless chickens

D) pest- and herbicide-resistant corn, cotton, and soybean crops (Pest- and herbicide-resistant genetically modified crops have become common in the US.)

Which of the following is not a product of recombinant DNA technology? A) recombinant human insulin B) recombinant human growth hormone C) recombinant human erythropoietin D) recombinant human diabetes E) All of the above are products of recombinant DNA technology.

D) recombinant human diabetes (Recombinant DNA technology can be used to manufacture human insulin, which is used by patients to treat diabetes.)

All of the following are required for CRISPR except: A) a plasmid. B) Cas9. C) RNA complementary to a gene of interest. D) restriction enzymes. E) a DNA sequence of interest.

D) restriction enzymes. (Although they are useful as a biotechnological tool, restriction enzymes are not part of the CRISPR gene-editing system. They are used to chop up DNA from donor organisms that exhibit traits of interest.)

Gene therapy can currently be used to cure which of the following conditions? A) dwarfism B) cystic fibrosis C) Tay-Sachs disease D) severe combined immunodeficiency disease (SCID) E) type 1 diabetes.

D) severe combined immunodeficiency disease (SCID) (SCID is currently the only disease that can be cured using gene therapy.)

Which development in biotechnology has been used to clear many innocent people of crimes that they were accused of committing?

DNA fingerprinting (DNA fingerprinting is used in forensic science to match a suspect's DNA to DNA found at a crime scene. Many innocent people who were initially convicted of crimes have been since exonerated because their own DNA failed to match DNA evidence found at the scene of a crime.)

What property of DNA allows it to be moved between two electrodes during electrophoresis?

DNA is negatively charged. (The negative charge of the DNA molecule carries it toward the positive electrode during electrophoresis)

This is how we do it: How do we determine whether GMOs are safe?

Determining whether genetically modified foods are safe is a complex and difficult challenge for scientists. We can, however, ask specific questions about potential dangers and use experimental approaches to collect evidence bearing on these questions. Although the issue of the safety of genetically modified food continues to be debated, there is growing consensus that GMOs carry no more risk than non-GMOs in the human diet.

Which of the following is a legal or philosophical argument against human cloning? A) issues of safety for the mother and child B) concerns of identity and individuality C) inability of cloned individual to give consent D) exploitation of women E) All of the above.

E) All of the above. (As the textbook points out, cloning has many potential benefits for medical research and agriculture. However, cloning a human being remains a touchy subject of debate.)

Which of the following statements about polymerase chain reaction (PCR) is false? A) Heat is used to separate a fragment of double-stranded DNA into two single strands. B) The number of copies of the DNA segment of interest doubles with each cycle. C) Each new copy of DNA includes one old strand and one newly synthesized strand. D) Each copy made is identical to the DNA segment of interest added at the beginning. E) DNA polymerase is needed to separate the DNA strands at the beginning of each cycle.

E) DNA polymerase is needed to separate the DNA strands at the beginning of each cycle. (DNA polymerase adds complementary bases to each single strand of DNA to build two identical double-stranded pieces of DNA.)

Examine the following lists, and choose the one that includes the components necessary to carry out PCR. A) DNA, restriction enzymes, a plasmid vector, and bacterial cells B) DNA, an RNA guide molecule, Cas9, and a plasmid vector C) DNA, restriction enzymes, a viral vector, and bacterial cells D) DNA, DNA polymerase, restriction enzymes, and free nucleotides E) DNA, DNA polymerase, primers, and free nucleotides

E) DNA, DNA polymerase, primers, and free nucleotides (The polymerase chain reaction requires the DNA of interest, the enzyme DNA polymerase, primers to direct the enzyme to the intended location, and free nucleotides to build new complementary DNA strands.)

Which of the following is not a possible scenario resulting from genetic engineering? A) Genetically modified featherless chickens are vulnerable to mosquitoes and parasites. B) Genetically engineered corn remains untouched in one field, while insects attack wild corn in an adjacent field. C) Genetically engineered, herbicide-resistant soybean plants can be sprayed with a chemical that kills weeds but does not harm the soybeans. D) Genetically engineered salmon escape from their breeding facilities and outcompete native salmon. E) Genetically engineered, herbicide-resistant rice is completely killed by application of that herbicide.

E) Genetically engineered, herbicide-resistant rice is completely killed by application of that herbicide. (This is not a plausible scenario. Herbicide-resistant rice would not be harmed by the application of herbicide. However, it is plausible that wild rice could be harmed by application of herbicide.)

Two healthy parents (asymptomatic) have a child with Tay-Sachs disease. Which of the following best explains this phenomenon and its possible screening? A) This phenomenon is not possible, since both parents are asymptomatic. B) The phenomenon occurred because both parents were gene carriers, but there is no testing available at this point for a disease such as Tay-Sachs. C) The phenomenon occurred because the dominant Tay-Sachs gene was active in the child, but not in the parents. D) The phenomenon occurred due to a point mutation that occurred during fertilization, but testing could have informed the parents of the disease in their unborn child. E) The phenomenon occurred because the parents are both carriers of the gene for the disease, but with screening of the parents combined with genetic counseling and embryo testing, the phenomenon could have dramatically been reduced.

E) The phenomenon occurred because the parents are both carriers of the gene for the disease, but with screening of the parents combined with genetic counseling and embryo testing, the phenomenon could have dramatically been reduced. (Individuals with only a single copy of the disease-causing gene never fully show the disease, but they may pass on the disease gene to their children.)

Which of the following could be used to transfer DNA into the genome of an organism? A) CRISPR B) polymerase chain reaction (PCR) C) bacteria D) restriction enzymes E) plasmids

E) plasmids (Bacterial plasmids—and, in some cases, viral vectors—can be used to transfer genetic material into a target organism's genome.)

restriction enzyme

Enzyme that cuts DNA at a specific sequence of nucleotides

How has recombinant DNA technology improved treatment of dwarfism?

Human growth hormone (HGH) can now be produced using transgenic bacteria. (Transgenic bacteria containing the gene for HGH can now produce the hormone at a much lower cost than harvesting it from cadavers.)

What is the function of Cas9 in the CRISPR process?

It cuts the target sequence into small pieces. (Cas9 is a restriction enzyme that functions to cut the target DNA during the CRISPR process.)

Rewards, with risks: what are the possible risks of genetically modified foods?

More and more genetically modified foods are being created through modern methods of recombinant DNA technology. For the public, however, numerous legitimate fears remain about the potentially catastrophic risks of these foods, given that their development relies on such new technology, and about the long-term financial advantages they offer.

Why should you be skeptical when you hear claims about biotechnology "breakthroughs" in the media?

Often what is reported as a breakthrough is only an early research finding. (Scientific discovery is a lengthy process. Early findings, although promising, are not necessarily the huge victories for biotechnology that media reports often make them out to be.)

transgenic organism

Organisms that contain functional recombinant DNA from a different organism

centromere

Region of a chromosome where the two sister chromatids attach

A researcher isolates a small segment of DNA. She heats the DNA in solution, causing its two strands to separate. What is the next step in this process?

She would cool the solution in the presence of DNA polymerase, primers, and free nucleotides. (Based on the brief description, the researcher is amplifying DNA through the process of PCR. After the solution is cooled and DNA polymerase, primers, and free nucleotides are added to the solution, DNA polymerase adds complementary bases to every single strand of DNA, creating two identical copies of the original DNA segment.)

What important processes underlie many biotechnology applications?

Some common technologies, techniques, or tools are employed in the applications of biotechnology. 1. Chopping up DNA from a donor organism 2. Amplifying DNA pieces into more useful quantities 3. Inserting foreign DNA into the target organism 4. Growing bacterial colonies that carry the DNA of interest: cloning

chiasmata

The X-shaped, microscopically visible region representing homologous chromatids that have exchanged genetic material through crossing over during meiosis.

What aspect of STRs is particularly useful in human identification?

The high degree of variability in the number of repeats at each location. (The level of variability in the number of repeats present at each STR location makes them extremely powerful in distinguishing the DNA fingerprints of different people, especially when analyzed across multiple STR locations.)

gene therapy

The insertion of working copies of a gene into the cells of a person with a genetic disorder in an attempt to correct the disorder

A farmer uses the same set of genetically modified crop plants every year. What risk will he encounter because of this practice?

The plants will be more susceptible to environmental conditions, pests, and diseases because of their limited genetic diversity. (Lack of genetic diversity can result in crops being more vulnerable to various stresses.)

What is biotechnology and what does it promise?

The use of technology to improve human health and agriculture is nothing new— neither is the basic idea behind biotechnology, or modifying organisms, cells, or molecules for use and application. However, with increasing knowledge of the structure and function of DNA, biotechnology has advanced greatly.

How does a restriction enzyme recognize the correct location to make cuts in a DNA sample?

They recognize a specific sequence of DNA and cut when they encounter that sequence. (Each restriction enzyme recognizes and cuts a different, specific sequence of bases in DNA. They can cut DNA from any source, as long as a specific four- to eight-base sequence is present.)

Which of the following statements about transgenic plants is true? A) Transgenic plants take many years to produce. B) Transgenic plants have been used successfully for insect resistance but not herbicide resistance. C) Transgenic plants contain genes from more than one species. D) All transgenic plants are dangerous to humans and animals and should never be consumed. E) Intermediate species are required for transgenic plants to be produced.

Transgenic plants contain genes from more than one species. (Any transgenic organism is one that has DNA inserted from a different species.)

What is a plasmid?

a circular piece of DNA that can be incorporated into the genome of a bacterium (This also allows for bacteria to adapt to environmental changes.)

genetically modified organism (GMO)

an organism produced by copying genes from a species with a desirable trait and inserting them into another species

Biotechnology has had limited success in what?

curing diseases (Although it has been effective in diagnosing and preventing diseases, biotechnology's efficacy has been limited in terms of curing diseases.)

Without the Cas9 enzyme, researchers would not be able to:

cut DNA at a precise location. (Cas9 is a DNA cutting enzyme that can be employed by researchers to cut a sequence of target DNA at a very precise location.)

cancer

disorder in which some of the body's cells lose the ability to control growth

Diabetes is to insulin as _________ is to _________.

dwarfism; human growth hormone (Insufficient human growth hormone (HGH) production, usually due to pituitary malfunctioning, leads to dwarfism. Individuals with dwarfism experience additional growth when treated with supplemental HGH.)

The manipulation of organisms' genetic material by adding, deleting, or transplanting genes from one organism to another is known as:

genetic engineering. (Genetic engineering is the general term for manipulating the genome, making changes that involve adding, removing, or transplanting DNA.)

recombinant DNA technology

has sped up this process, enabling the combination of DNA from two or more sources into a product.

"Genetically modified foods are unnatural; therefore, they are harmful." This argument is:

invalid; when evaluating if something is either beneficial or harmful, there is no value in knowing whether it is natural or unnatural. (The argument is invalid because there are numerous "natural" things in our world—from diseases to poisons—that cause harm. By the same token, there are "unnatural" things, such as vaccines, that are immensely beneficial.)

When creating a DNA fingerprint using gel electrophoresis, the smallest fragments of DNA:

move the most quickly across the gel. (Having fewer repeats, smaller pieces of DNA move across the gel more quickly.)

Polymerase chain reaction (PCR) allows:

multiple copies of DNA to be made. (PCR allows scientists to take a single piece of DNA and duplicate it, repeatedly.)

chromatid

one half of a duplicated chromosome

Human growth hormone is produced by the ______________, and erythropoietin is produced by the __________________.

pituitary gland; kidneys (Under normal circumstances, the pituitary gland produces human growth hormone, and the kidneys produce erythropoietin. Recombinant DNA technology has been used to successfully produce both human growth hormone and erythropoietin.)

What farming practice might have prevented the Irish Potato Famine?

planting multiple varieties of potato (Genetic diversity in potato crops could have prevented the widespread devastation that occurred because only the variety planted was susceptible to a disease.)

apoptosis

programmed cell death

A human growth hormone gene is placed into a bacterial plasmid. This is an example of:

recombinant DNA. (Recombinant DNA includes genetic material from two or more sources. In this example, a human growth hormone gene has been inserted into bacterial DNA.)

cell cycle

series of events that cells go through as they grow and divide

Which of the following has been successfully treated using gene therapy? A) heart disease B) Alzheimer's disease C) severe combined immunodeficiency disease (SCID) D) blindness due to vitamin A deficiency E) type 1 diabetes

severe combined immunodeficiency disease (SCID) (Several dozen cases of SCID have been cured using gene therapy. Two patients did, however, die from illness related to treatment.)

What is the target cell type for gene therapy to cure severe combined immunodeficiency disease (SCID)?

stem cells (Stem cells from the bone marrow of patients with SCID can be removed, modified, and reinserted during gene therapy.)

checkpoints

stop to the cell cycle to check for damage

genetic engineering

the manipulation of organisms' genetic material by adding, deleting, or transplanting genes from one organism to another

anaphase

the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles

biotechnology

the use of technology to modify organisms, cells, and their molecules to achieve practical benefits. The primary areas in which biotechnology is applied include agriculture, human health, and forensic science.

In which of the following laboratory situations would a restriction enzyme be the best tool to use?

to cut out a fragment of DNA from a bacterial genome that contains a gene coding for Bt crystals (Restriction enzymes are used to cut DNA.)

Recombinant human growth hormone and recombinant human erythropoietin are two examples of products produced by:

transgenic organisms. (Both are examples of products created by inserting human genes into bacterial cells (recombinant human growth hormone) and hamster cells (recombinant human erythropoietin).)

stem cell

unspecialized cell that can give rise to one or more types of specialized cells