GBIO 107 Ch. 11

PCR is a technique used to amplify trace amounts of ___________ to be used in scientific and forensic analyses.

DNA

What are steps in preimplantation genetic diagnosis?

Eggs are fertilized in vitro, DNA is extracted from an embryonic cell and amplified by PCR, amplified DNA is exposed to a DNA probe for a disease- causing allele, and an embryo with DNA that does not contain disease-causing alleles can be implanted into t

Order the steps of the polymerase chain reaction.

1.) Add target DNA, heat-stable DNA polymerase, primers, and nucleotides to reaction mixture.
2.) Heat to separate strands of target DNA.
3.) Cool to allow primer attachment.
4.) DNA polymerase adds nucleotides to the primers and synthesizes copies of the

The cloning technique that was used to create the first cloned mammal (a sheep named Dolly) was called ____________ cell nuclear transfer.

somatic

____________ stem cells are more differentiated and produce a limited number of cell types.

Adult

A(n) _____________ _____________ is a type of a protein that can cut double-stranded DNA at specific base sequences.

restriction enzyme

Order the steps of somatic cell nuclear transfer to create a clone of an adult mammal.

1.) Obtain nucleus from a somatic cell of a donor individual.
2.) Insert the somatic nucleus into a denucleated egg cell.
3.) Cell divides by mitosis to form an embryo.
4.) Implant the embryo into a surrogate mother.
5.) Embryo undergoes development and i

Order the steps for using a DNA probe to indicate the presence of a disease allele, beginning with the first step at the top.

1.) Synthesize a probe, a single-stranded piece of DNA that is complementary to part of a disease allele.
2.) Label the probe with a radioactive isotope or fluorescent tag.
3.) Immobilize the single-stranded source DNA and expose it to the probe.
4.) The

____________ therapy is the process of adding a healthy gene that supplements the function of a faulty gene in a person's cells.

Gene

What type of organism is one that receives and expressed recombinant DNA?

transgenic

What are the current uses of transgenic bacteria and yeasts?

Degradation of pollutants, production of milk curding enzymes for the cheese industry, and production of phenylalanine.

Order the steps of creating a transgenic organism.

1.) Acquire source DNA and cloning vector.
2.) Cut source and vector DNA with the same restriction enzyme.
3.) Mix donor DNA and vector DNA and seal segments together.
4.) Insert recombinant DNA into a recipient cell.

The fact that different species use the same genetic code means that a(n) _____________ from one organism can be transcribed and translated in a different organism.

gene

Some restriction enzymes produce ______________ ends in both the source DNA and plasmid DNA, and these ends can stick to each other by _____________.

Single-stranded; complementary base pairing

The process of determining the order of DNA nucleotides in a stretch of DNA is called

DNA sequencing

What are the disadvantages of cloning humans?

Obtaining eggs from a woman's ovaries is costly and risky, embryos would have to be destroyed, and most clones do not develop normally or die in early development.

An undifferentiated cell that can give rise to specialized cell types is called a(n)

stem cell

Order the steps in DNA profiling.

1.) Extract source DNA.
2.) Amplify STR sites of DNA with PCR incorporating a fluorescent label.
3.) Use electrophoresis and fluorescence imaging to determine number of repeats at each STR site.
4.) Use statistical analysis to compare source DNA to other

A common type of cloning vector is a(n) _________________, which is a small circle of double-stranded DNA separate from the cell's chromosome.

plasmid

What is routinely done to screen for phenylketonuria (PKU) in newborns?

genetic testing

Why might adult stem cells be better for use in stem cell therapy than embryonic stem cells?

Adult stem cells can be derived from the patient's own tissues, using adult stem cells would not involve human embryos, and a patient's immune system would not reject its own tissues.

Methods that involve the manipulation of genes or specific sequences of DNA are part of a broad category of research and practical applications called DNA

technology

What can be sources of DNA used to create a transgenic organism?

Plant, bacterium, and animal

To create a transgenic organism, researchers must use a cloning ______________, such as a plasmid, to carry source DNA into a recipient cell.

vector

In biotechnology, the process of analyzing variable parts of a genome to detect genetic differences between individuals is called

DNA profiling

What enzyme is used to make cDNA, an intron-free DNA copy of mRNA?

reverse transcriptase

As determined by the Human Genome Project, the human genome includes approximately 25,000 protein-encoding

genes

What are applications of the amplification of DNA using the polymerase chain reaction (PCR)?

Identify human remains, DNA profiling to determine guilt of a suspect, and establish family relationships

What describes cloning as a method of reproduction?

At least some organisms in each kingdom reproduce by cloning and cloning is essentially asexual reproduction.

What are the steps that researchers used to make transgenic rice that expresses high amounts of a "booster gene" that allows them to survive herbicide treatment?

1.) Isolate rice DNA.
2.) Use a restriction enzyme to cut out the gene of interest.
3.) Attach the gene to a promoter that makes the gene "always on."
4.) Insert the gene and promoter into a plasmid.
5.) Use Agrobacterium to transfer the plasmid to rice c

What is required for the polymerase chain reaction?

DNA polymerase, DNA sequence to be replicated, primers, and regular nucleotides

A bacterium that has received recombinant DNA containing the gene for human insulin will

produce human insulin along with the other proteins it normally produces.

What are potential ethical issues in using genetic testing?

PGD is expensive and may only be possible for the wealthy, parents may use genetic testing to select for desirable traits in embryos, and tests that reveal a high risk of cancer may cause anxiety or depression.

Transferring genes to enhance appearance or performance and transferring genes to germ-line cells are two moral and ethical issues associated with what DNA technology?

gene therapy

How do researchers prepare an intron-free copy of a eukaryotic gene for use in creating transgenic bacteria?

Use reverse transcriptase to make cDNA from mature mRNA

Why are short tandem repeats (STRs) useful in DNA profiling?

They are genetically variable

What composes 98.5% of the human genome that does not encode proteins?

repetitive sequences, transposons, enhancers, DNA that codes for rRNA and tRNA, and pseudogenes

What pharmaceuticals can be produced using transgenic bacteria?

fertility hormones, blood clotting factors, and insulin

Order the steps of DNA sequencing.

1.) Place primers, replication enzymes, unknown sequence, normal nucleotides, and terminator nucleotides into reaction mixture.
2.) DNA polymerase adds nucleotides to primers.
3.) DNA replication stops each time a terminator nucleotide is added.
4.) Sampl

What are applications of DNA technology?

manipulate gene expression to treat diseases, study evolutionary relationships among species, and modify crop plants to be insect-resistant

What are ways that genetic testing can be used in adults?

Indicate if individuals are heterozygous carriers of disease alleles, test for alleles that code for targets of disease therapy, and test for presence of disease allele common in family.

The possible termination of embryos or fetuses with mild conditions or less desirable traits is a moral and ethical dilemma associated with

genetic testing

If source DNA is extracted from a eukaryotic organism and used to create transgenic bacteria, why will the mRNA transcribed from the recombinant DNA encode a defective protein in the bacteria?

Eukaryotic DNA contains introns, which bacteria cannot remove.

What bacterium enters plants at a wound site and injects a plasmid into the plants' cells, causing a tumorlike gall to grow where the bacteria can live?

Agrobacterium tumefaciens

What are applications of creating transgenic plants?

Viral resistance, enhanced nutrients, herbicide resistance, and insecticide production

What aspects of gene transfer therapy that differ from the process of creating a transgenic organism?

In gene therapy, inserted genes are from the same type of organism, and gene therapy patients do not pass the gene on to their offspring.

What are the applications of transgenic animals?

Provide a model for disease development, production of human proteins in the milk of farm animals, and increase yield for human consumption.

What portions of the noncoding human genome that have functions for the cell?

enhancers and sequences that encode tRNA, rRNA, and microRNA

A _______________ is a self-replicating genetic structure that will carry source DNA into a recipient cell.

cloning vector

Unlike creating a transgenic organism, in gene therapy,

genes are only inserted into the cell type that needs correction.

What type of transgenic organisms can be produced to contain extra nutrients, to survive harsh conditions, or to degrade leftover explosives at military installations?

transgenic plants

What diseases are caused by mutated alleles of genes and that can be detected and possibly treated using DNA technology?

hemophilia, Tay-Sachs disease, sickle cell disease, and cystic fibrosis

What are applications of stem cell technology?

Provide specific cells for drug testing, replace injured or damaged tissue, and treat incurable diseases

RNA interference can silence a disease-causing gene because

complementary mRNA binds to the gene's mRNA, preventing translation.

The same gene is able to code for different proteins depending on the combinations of introns removed from a(n) ________________ molecule.

mRNA

The bacterium Bacillus thuringiensis produces __________________ that is toxic to insects and can be inserted into plants using recombinant DNA.

Bt protein

Within the noncoding portion of the human genome, ___________________ are DNA sequences that resemble protein-encoding genes, but their mRNA is not translated.

pseudogenes

DNA technology is especially useful in detecting and treating what types of human diseases?

diseases associated with a single gene

What type of technology could be used to produce new cells of a specific type to help treat diseases?

stem cell technology

What correctly describes the structure and function of DNA?

DNA is a double helix of nucleotides, DNA encodes a cell's proteins, and DNA is copied before a cell divides.

What describes a use of DNA technology that can help solve crimes, match parents with offspring, or otherwise identify particular individuals?

DNA profiling

What nonhuman mammals have been cloned by somatic cell nuclear transfer?

cattle and sheep, dogs and cats, and mice

What potential problems must be overcome in gene therapy?

Genes must be delivered only to cells that express the faulty alleles, virus vectors can trigger an immune reaction, and the new DNA can induce mutations that cause cancer.

What are applications of DNA profiling using mitochondrial DNA?

verifying relationships between woman and child and revealing patterns of human evolution

What ways can a baby be born with a disease despite preimplantation genetic diagnosis?

PCR is extremely sensitive such that stray DNA can indicate a false result, technicians can make an error, and only the most common mutations causing a disease are detected.

What is the advantage of producing transgenic organisms called Bt crops?

Farmers can reduce the use of insecticides

What technology can be used to block the translation of mRNA and therefore silence a cancer-related gene?

RNA interference

One way that a cell can produce many proteins from few genes is by removing different combinations of ________________ from an mRNA molecule.

introns

What are potential disadvantages of creating genetically modified organisms?

Genes are combined in ways that don't occur in nature and the costs of producing and testing transgenic plants are high.

DNA sequences that are very similar to protein-encoding genes but are not translated are called ___________________, which may be remnants of old genes that once functioned in ancestors.

pseudogenes

What are applications of comparing DNA sequence similarities?

trace inheritance of alleles in families and reveal evolutionary relationships among species

What are all the problems associated with cloning mammals?

Details of reproduction and gene regulation mechanisms are hard to replicate, success rate for cloning is low, and lifespan of clones is sometimes abnormally brief.

The use of cuttings from stems, roots, or leaves to produce new plants is an example of

cloning.

What are ethical concerns associated with the use of transgenic organisms?

Replacement of wild species by transgenics and new protein combinations could trigger allergies

Adult stem cells are ___________________, are able to give rise to a limited set of cell types, whereas embryonic stem cells are ___________________, able to give rise to ALL cell types.

pluripotent; totipotent

What recent technique holds promise for reducing the drawbacks to using stem cell therapy?

inducing differentiated cells to behave like stem cells

How do scientists create transgenic animals?

using viruses to carry recombinant DNA into a gamete or egg cell

What ways can the cloning vector with recombinant DNA be inserted into a recipient cell?

Opening the recipient bacterial cell with electricity, allowing a virus attached to the DNA to infect a recipient cell, using gene guns to shoot DNA-coated pellets into cells, packaging recombinant DNA into a liposome that fuses with the cell membrane.

What type of DNA is exclusively passed from mother to offspring and can sometimes be used in DNA profiling when nuclear DNA is degraded?

Mitochondrial DNA

ATTCGATTCG repeated many times, the number varying from person to person, is a type of noncoding DNA called a ____________ and is often used in DNA profiling.

tandem repeat

What aspect of DNA allows scientists to trace inheritance and even evolutionary history between species?

similarities and differences in nucleotide sequences

Using gene guns, liposomes, or infective viruses are ways to conduct what step in creating a transgenic organism?

inserting recombinant DNA into the recipient cell

Researchers may be able to induce adult cells to behave like ____________, an important advance in stem cell therapy.

embryonic stem cells

In creating transgenic animals, what cloning vector is often used to transfer recombinant DNA?

viruses

Embryonic stem cells are totipotent and able to _________________. However, adult stem cells are pluripotent and able to ________________.

Produce all cell types of the body; produce a limited subset of cell types.