Bio Chapter 12

what was the health of pigs measured over?

the short term (31 days), the medium term (110 days), and the normal generational life span

what is the second step of the PCR cycle?

the strands are cooled. As they cool, primer molecules hydrogen-bond to their target sequences on either end of the target DNA

what is genomics?

the study of complete sets of genes

what was the first eukaryote to have its full sequence determined?

Baker's yeast (Saccharomyces cerevisiae), a single-celled organism

what are all the genomes that have been sequenced a part of?

a larger effort to collect information on all of the genetic variations that affect human characteristics

what are comparisons with neanderthals and chimpanzees a part of?

a larger effort to learn more about the human genome

what was the human genome project (HGP)?

a massive, publically funded scientific endeavor to determine the nucleotide sequence of all DNA in the human genome and identify the location and sequence of every gene

what is STR analysis?

a method of DNA profiling that compares the lengths of STR sequences at specific sites in the genome

what was the initial path that the HGP proceeded along?

a methodical one that built on an earlier storehouse of human genetic information

from an evolutionary perspective, what is genetic variety?

a necessary ingredient for the survival of a species as environmental conditions change with time

what is another technique using nucleic acid probes?

a piece of filter paper is pressed against bacterial colonies (clones) growing on a petri dish

what is a common vector used to introduce new genes into plant cells?

a plasmid from the soil bacterium Agrobacterium tumefaciens called the Ti plasmid

what is the enzyme made by carrot cells in culture used to treat?

a rare human genetic condition called Gaucher's disease

what is the resulting plasmid?

a recombinant DNA molecule

what was the first human genome to be sequenced?

a reference genome compiled from a group of individuals

how can a researcher overcome the problem of wishing to clone eukaryotic genes—which usually contain stretches of non-coding introns—in prokaryotic cells, which lack the machinery to remove introns?

a researcher can use mRNA as the starting material for cloning

what happens when the current is turned off in gel electrophoresis?

a series of bands is left in each "lane" of the gel

what have scientists developed to guard against rogue microbes?

a set of guidelines, including strict laboratory safety and containment procedures, the genetic crippling of transgenic organisms to ensure that they cannot survive outside the laboratory, and a prohibition on certain dangerous experiments

what happens in machines that carry out next-generation sequencing?

a single template strand of DNA is immobilized, and DNA polymerase and other reagents are added that allow sequencing by synthesis of the complementary strand, one nucleotide at a time

what is third-generation sequencing?

a single, very long DNA molecule is sequenced on its own

what is the polymerase chain reaction (PCR)?

a technique by which a specific segment of a DNA molecule can be targeted and quickly amplified (copied in quantity) in the laboratory

what is a gel?

a thin rectangle of jellylike material often made from agarose, a carbohydrate polymer extracted from seaweed

what is Golden Rice?

a transgenic variety created in 2000 with a few daffodil genes, that produces yellow grains containing beta-carotene, which our body uses to make vitamin A

where can the DNA containing gene V come from?

a variety of sources, such as a different bacterium, a plant, a nonhuman animal, or even human tissue cells growing in laboratory culture

what did researcher infect the mice with (in the 2015 study)?

a virus carrying the Cas9/guide RNA complex

what does the National Center for Biotechnology Information (NCBI) maintain?

a website with many tools for accessing GenBank, its sequence database

what may researchers be able to do by observing the mutant cell or organism?

determine the function of the knocked out gene

since the birth of genomics, what have researchers used tools and techniques of DNA technology to do?

develop more and more detailed maps of the genomes of a number of species

what is DNA technology helping medical researchers do?

develop vaccines

when did DNA profiling first gain wide public attention?

during the highly publicized 1995 murder trial of former football star O. J. Simpson. DNA analysis proved that blood in Simpson's car belonged to the victims and that blood at the crime scene belonged to Simpson

what is the second main type of repetitive DNA?

each repeated nucleotide sequence is hundreds of bases long, and the copies are scattered around the genome

what can the CRISPR-Cas9 system be used to do other than knock out a gene?

edit a gene

what are some of the successes of gene therapy that have occurred from 200 to 2011?

gene therapy cured 22 children with severe combined immunodeficiency (SCID), a fatal inherited disease caused by a defective gene that prevents development of the immune system, requiring patients to live within protective "bubbles."

what could Golden rice do?

help prevent vitamin A deficiency, which causes blindness in a quarter million children each year

what do critics argue about using pigs as a model organism for human digestion?

human data are required to draw conclusions about the safety of dietary GMOs for people

what are mammalian cells also used to produce?

human erythropoietin (EPO), a hormone that stimulates the production of red blood cells; EPO can save lives as a treatment for anemia

as of 2016, what does GenBank include?

more than 200 billion base pairs

what have sheep been geneticallly modified to do?

produce a human protein called AAT. This protein can be supplied to patients to treat a hereditary form of emphysema

what does the rest of DNA that is not introns include?

some unique (single-copy) noncoding DNA, such as former genes that have accumulated mutations over a long time and no longer produce functional proteins

why wouldn't PCR be possible without a heat-stable polymerase?

standard DNA polymerases would denature (unfold) during the heating step of each cycle

what does the whole-genome shotgun method start with?

the cloning and sequencing of DNA fragments from randomly cut DNA derived from the entire genome

what is often the first choice eukaryotic organism for protein production?

the same yeast used in making bread and beer, Saccharomyces cerevisiae

what can DNA technology pinpoint?

microorganisms responsible for disease outbreaks

what is the CRISPR-Cas9 technique a highly successful way for researchers to do?

"knock out" (disable) a given gene

what did a 2012 animal study involve?

104 pigs that were divided into two groups: The first was fed a diet containing 39% GMO corn and the other a closely related non-GMO corn

what is the first step in gel electrophoresis?

A DNA sample from each source is placed in a separate well (hole) at one end of a gel

what is the first step in gene therapy?

A gene from a healthy person is cloned, converted to an RNA version, and then inserted into the RNA genome of a harmless virus

what is the third step in gel electrophoresis?

A negatively charged electrode from a power supply is attached near the end of the gel containing the DNA, and a positive electrode is attached near the far end

what is the simple process of PCR?

A repeated three-step cycle acts as a chain reaction that doubles the population of identical DNA molecules during each round

what is a restriction site?

A specific sequence on a DNA strand that is recognized as a "cut site" by a restriction enzyme

what enzyme is chosen to cut DNA in gene cloning?

An enzyme is chosen that cleaves the plasmid in only one place

what is one of the difficulties in conducting research on human safety?

Animal studies are of limited value, but human studies may be unethical

what is the third step in using mRNA as the starting material for cloning?

Another enzyme is added to break down the mRNA

why can agarose act as a molecular sieve?

Because agarose contains a tangle of cable-like threads

why do the DNA molecules all travel through the gel toward the positive pole?

Because all nucleic acid molecules carry negative charges on their phosphate groups

why must mammalian cells be used for making glycoproteins?

Because only mammalian cells can attach the sugars correctly

why does the DNA polymerase duplicate only the desired segments of DNA?

Because the primers only bind the sequences associated with the target

what is the second step in gene therapy?

Bone marrow cells are taken from the patient and infected with the recombinant virus

what are prime candidates for cells that multiply throughout a person's life?

Bone marrow cells, which include the stem cells that give rise to all the cells of the blood and immune system

what is the result of Cas9 being directed by RNA?

Cas9 cuts both strands of any DNA sequence that is complementary to the guide RNA

what was the uproar caused by the chinese schoolchildren study?

Chinese authorities called the study an unethical "scandal," complaining that U.S. scientists had used Chinese schoolchildren as laboratory subjects

what is one purpose of gene cloning?

Copies of the gene itself can be the immediate product, to be used in additional genetic engineering projects

what are plasmids key tools for?

DNA cloning, the production of many identical copies of a target segment of DNA

what did scientists discover that each spacer sequence corresponded to?

DNA from a particular virus that had infected the cell

what is the fourth step in using mRNA as the starting material for cloning?

DNA polymerase is used to synthesize a second DNA strand

what is the most important application to forensics?

DNA profiling, the analysis of DNA samples to determine whether they came from the same individual

what happens after Cas9 cuts both strands of its target?

DNA repair enzymes randomly insert nucleotides as they reconnect the target DNA, usually rendering the gene nonfunctional

what is the modern for of biotechnology?

DNA technology, modern laboratory techniques for studying and manipulating genetic material

what happens in one standard next generation sequencing procedure?

DNA to be analyzed is cut into fragments, and then each fragment is sequenced using automated machines

T or F: the size of genomes and number of genes depends on the organism's size, complexity, and appearance

F

T or F: there is general agreement among scientists that the GMO foods on the market are unsafe

F

T or F: there must be large, unaffected amounts of DNA present in the starting material of PCR?

F: Only miniscule amounts of DNA need to be present in the starting material, and the DNA can even be in a partially degraded state

T or F: genetically engineered animals are easy to produce

F: genetically engineered animals are difficult and costly to produce

T or F: biotechnology is a modern field

F: it dates back to the dawn of civilization

what is one gene that changed rapidly in the human lineage?

FOXP2, a gene implicated in speech and vocalization

what is the third step in DNA profiling?

Finally, the amplified DNA markers are compared, providing data about which samples are from the same individual

what is the third step in using the Ti plasmid to introduce new genes into plant cells?

Finally, the recombinant cell is cultured and grown into a plant

what is the first step in DNA profiling?

First, DNA samples are isolated from the crime scene, suspects, victims, or other evidence

what were some serious side effects of treating SCID with gene therapy?

Four of the treated patients developed leukemia, and one died after the inserted gene turned the patient's blood cells cancerous

what did the results lead researchers to conclude in the Chinese schoolchildren experiment?

GMO rice can indeed be effective in preventing vitamin A deficiency

today, what does most public concern about DNA technology center on?

GMOs used for food

what is the third step of the PCR cycle?

a heat-stable DNA polymerase builds new DNA strands by extending the primers

what happened involving insulin in 1982?

Humulin—human insulin produced by bacteria—became the first recombinant DNA drug approved by the U.S. Food and Drug Administration

what is a transgenic organism?

If a gene is transplanted from one organism into another, typically of another species

what is a nucleic acid probe?

In DNA technology, a radioactively or fluorescently labeled single-stranded nucleic acid molecule used to find a specific gene or other nucleotide sequence within a mass of DNA. The probe hydrogen-bonds to the complementary sequence in the targeted DNA.

what is going on in India involving GMOs?

In India, the insertion of a natural but rare salinity-resistance gene has enabled new varieties of rice to grow in water three times as salty as seawater, allowing food to be grown in drought-stricken or flooded areas

what is the second step in the whole-genome shotgun method?

Mapping software then assembles the millions of overlapping short sequences into a single, continuous sequence for every chromosome—an entire genome

what did the genomic analysis of the female neanderthal confirm?

Neanderthals were a separate species from us (Homo sapiens) and our closest relatives, much closer than chimpanzees

what is the second step in DNA profiling?

Next, selected markers from each DNA sample are amplified (copied many times), producing a large sample of DNA fragments

how do the primers work?

One primer is complementary to one strand at one end of the target sequence; the second primer is complementary to the other strand at the other end of the sequence. The primers thus bind to sequences that flank the target sequence, marking the start and end points for the segment of DNA being amplified

what makes plasmids ideal for manipulating genes?

Plasmids typically carry only a few genes, can easily be transferred into bacteria, and are passed from one generation to the next

how can CRISPR be used to edit a gene?

Researchers can introduce a segment from the normal (functional) gene along with the Cas9/guide RNA complex

what did researchers find when treating children affected with LCA?

Researchers found that a single injection—containing a virus carrying the normal gene—into one eye of affected children improved vision in that eye, sometimes enough to allow normal functioning

what happens to SCID patients unless they are treated with a bone marrow transplant, which is effective only 60% of the time?

SCID patients quickly die from infections by microbes that most of us fend off

what is the second step in using mRNA as the starting material for cloning?

Single-stranded DNA transcripts are made from the mRNA using reverse transcriptase, a viral enzyme that can synthesize DNA from an RNA template

what was one experiment conducted by Chinese and American scientists in 2012?

Sixty-eight Chinese schoolchildren were fed Golden Rice, spinach, or a capsule containing pure beta-carotene; Over 21 days, blood samples were drawn to measure how much vitamin A the body produced from each food source; The data show that the beta-carotene in both Golden Rice and the capsules was converted to vitamin A in the body with similar efficiency, while the beta-carotene in spinach led to significantly less vitamin A

T or F: DNA sequencing technology is rapid and inexpensive

T

T or F: The same restriction enzyme will always cut all copies of a particular DNA molecule at the same place

T

T or F: each of the 13 sites vary from person to person

T

T or F: products made from GMOs are required to be labeled in any way

T

T or F: until recently, Parkinson's disease was not known to have a hereditary component

T

what is the first step in using mRNA as the starting material for cloning?

The chosen cells transcribe their genes within the nucleus, producing mRNA. The researcher isolates the mRNA in a test tube

what are restriction enzymes?

The cutting tools that cut DNA that are bacterial enzymes

what is the fourth step in gene therapy?

The engineered cells are then injected back into the patient. The normal gene is transcribed and translated within the patient's body, producing the desired protein

what is the second step in gel electrophoresis?

The gel is immersed in liquid within a plastic holding tray

what is the biggest challenge in genetic engineering?

The gene of interest is one relatively tiny segment embedded in a much longer DNA molecule (hard to find)

what happens after the biologist cuts the DNA?

The source DNA, which is usually much longer in sequence than the plasmid, may be cut into many fragments, only one of which carries gene V

what is the third step in gene therapy?

The virus inserts a DNA version of its genome, including the normal human gene, into the cells' DNA

what advantage do plant cells provide over animal cells?

Their cells are easily grown in culture, requiring less precise conditions than animal cells, plant cells are unlikely to be contaminated by viruses that infect humans, a situation that helps to increase safety

what is the second step in using the Ti plasmid to introduce new genes into plant cells?

Then the recombinant plasmid is put into a plant cell, where the DNA carrying the new gene integrates into one of the plant's chromosomes

how can DNA technology serve as a diagnostic tool?

Through DNA analysis, many inherited diseases—including sickle-cell disease, hemophilia, cystic fibrosis, and Huntington's disease—can be identified in an individual before the onset of symptoms, even before birth

what do most multicellular eukaryotes have?

a huge amount of noncoding DNA; about 98.5% of human DNA is of this type

what is gene cloning?

When DNA cloning involves a gene-carrying segment of DNA

how reliable is DNA profiling?

When the standard CODIS set of 13 STR sites is used correctly, the probability of finding the same DNA profile in randomly selected, unrelated individuals is less than one in 10 billion

what are genetically engineered animals?

Whole animals that have been produced using recombinant DNA

what is the first step in using the Ti plasmid to introduce new genes into plant cells?

With the help of a restriction enzyme and DNA ligase, the gene for the desired trait is inserted into a modified version of the plasmid

what can be the result of cloning a genetically engineered animal?

a genetically identical herd—a grazing pharmaceutical "factory" of "pharm" animals that produce otherwise rare biological substances for medical use

what is a vaccine?

a harmless variant (mutant) or derivative of a pathogen—usually a bacterium or virus—that is used to stimulate the immune system to mount a lasting defense against that pathogen, thereby preventing disease

what is DNA ligase?

a "DNA pasting" enzyme that catalyzes the formation of covalent bonds between adjacent nucleotides, joining the strands

what happened at nearly the same time that the first human genome was sequenced?

a biotechnology company sequenced the genome of its president

what is each band in gel electrophoresis?

a collection of DNA fragments of the same length

in this clone, what does each bacterium carry?

a copy of gene V

in the US, what is the number of repeats at each site entered into?

a database called CODIS (Combined DNA Index System) administered by the Federal Bureau of Investigation

what did a 2009 gene therapy trial involve?

a disease called Leber's congenital amaurosis (LCA)

what are bacteria used for?

a wide variety of purposes, from producing valuable human drugs—including insulin, growth hormone, and cancer treatments such as Taxol and interleukin-2—to enzymes used in making cheese and processed fruit juices, and for breaking down cellulose for animal feeds

what do people with one form of LCA produce?

abnormal rhodopsin, a pigment that enables the eye to detect light

what will genomic studies do?

advance our understanding of all aspects of biology, including health, ecology, and evolution

what has PCR been used to do?

amplify fragments of DNA from a wide variety of sources

what is the genetic link between Parkinson's and Alzheimer's?

an altered version of the protein encoded by this Parkinson's gene has also been tied to Alzheimer's disease

what are carrot cells in culture used to make?

an enzyme involved in fat breakdown

what is one example of a disease-associated gene that has been identified using a complete map of the human genome?

an inherited type of Parkinson's disease, a debilitating brain disorder that causes tremors of increasing severity

when did Neanderthals appear and how long did they survive?

appeared at least 300,000 years ago in Europe and Asia and survived until about 30,000 years ago

how many nucleotide pairs does the haploid set of human chromosomes contain?

approximately 3 billion

How was CRISPR-Cas9 discovered?

as a natural component of prokaryotic cells

where are stretches of DNA with thousands of short repetitions prominent?

at the centromeres and telomeres (ends) of chromosomes, suggesting that this DNA plays a role in chromosome structure

more recently, what have scientists developed techniques to do?

augment or replace next-generation sequencing

what is DNA technology used to do today?

augment traditional breeding programs as scientists work to improve the productivity of agriculturally important plants and animals

what would tinkering with zygotes in gene therapy result in?

changes that are passed on to future generations, permanently altering the genetic lineage

what were the first targets of genomics research?

bacteria, which have relatively little DNA

what are often the best organisms to use in manufacturing a protein product?

bacteria-most commonly E. coli

why is a nucleic acid probe called a nucleic acid probe?

because it is used to find a specific gene or other nucleotide sequence within a mass of DNA

why may assembling and analyzing proteomes pose many experimental challenges?

because of the huge number of proteins and the myriad ways that their production can be controlled

why are GMOs used in crop production?

because they are more nutritious or because they are cheaper to produce

when did the HGP begin and when was it completed?

began in 1990 and was completed in 2003 with more than 99% of the human genome determined to 99.999% accuracy

what have the successes in the field of genomics encouraged scientists to do?

begin similar systematic studies of the full protein sets (proteomes) encoded by genomes, an approach called proteomics

what is a chemical treatment used to do to the bacteria on the filter paper?

break open the cells and separate the DNA strands

how has genetic engineering largely solved the problem of insulin?

by developing bacteria that synthesize and secrete the human form of insulin

how are agricultural researchers producing transgenic animals?

by genetically modifying the nuclei of embryos, either through gene cloning or through the CRISPR-Cas9 system->The engineered embryos are then surgically implanted into a surrogate mother. If an embryo develops successfully, the resulting animal will contain a new or modified gene

how may GMO crops be able to help a great many hungry people?

by improving food production, shelf life, pest resistance, and the nutritional value of crops

typically, how does a biotechnology company start producing a genetically engineered animal?

by injecting the desired DNA into a large number of animal embryos, which are then implanted into surrogate mothers

how have scientists been able to exploit the natural function of Cas9?

by introducing a Cas9-guide RNA complex into a cell they wish to alter

how does gel electrophoresis separate DNA fragments?

by length, with shorter molecules migrating toward the positive end faster

how can the bands in gel electrophoresis be made visible?

by staining, by exposure onto photographic film (if the DNA is radioactively labeled), or by measuring fluorescence (if the DNA is labeled with a fluorescent dye)

under the right conditions, how does a bacterium take up the plasmid?

by transformation

how can a scientist use PCR to create a DNA profile?

by using primers that match the nucleotide sequences flanking the STR sites-> The resulting DNA molecules are then compared by gel electrophoresis

what is treatment with human growth hormone a boon to?

children born with a form of dwarfism caused by inadequate amounts of this hormone

what happens to children with HGH deficiency because growth hormones from other animals are not effective in humans?

children with HGH deficiency historically have had to rely on scarce and expensive supplies extracted from human cadavers

what does one software program available on the NCBI website, called BLAST, allow the user to do?

compare a DNA sequence with every sequence in GenBank, base by base

what can another NCBI program do?

compare a collection of DNA sequences from different species and diagram them in the form of an evolutionary tree based on the sequence relationships

what can researchers now do using databases like GenBank?

compare genome sequences from many species, allowing hypotheses about evolutionary relationships between those species to be tested

what can forensic scientists do by focusing on STRs?

compare the tiny fraction of the genome that is most likely to be different

what does the current standard for DNA profiling in forensic and legal systems do?

compares the number of repeats of specific four-nucleotide DNA sequences at 13 sites scattered throughout the genome

what is the DNA that results from using mRNA as the starting material for cloning?

complementary DNA (cDNA)`

what is the guide RNA in the complex made to be?

complementary to a target DNA sequence, such as a gene

what did researchers alter live mice cells to do?

correct a faulty gene that causes tyrosinemia, a disease affecting metabolism of the amino acid tyrosine, which can lead to organ dysfunction and developmental disabilities

what can researchers exploit the principle of complementary base pairing to do?

determine the complete nucleotide sequence of small DNA molecules-> DNA sequencing

what do some critics worry that tampering with human genes will lead to?

eugenics, the deliberate effort to control the genetic makeup of human populations

despite the advantages of using bacteria, what it is sometimes desirable or necessary to use to produce a protein product?

eukaryotic cells

what are other research efforts doing?

extending genomic studies to other species

what can scientists do using DNA technology?

extract genes from one organism and transfer them to another, effectively moving genes between species

in 2014, what did researchers use the CRISPR-Cas9 sustem to do?

fix a genetic defect in mice

how is cDNA useful?

for studying the genes responsible for the specialized functions of a particular cell type, such as brain or liver cells

What is recombinant DNA?

formed when scientists combine pieces of DNA from two different sources—often different species—in vitro (in a test tube) to form a single DNA molecule

what do a great many DNA technology applications rely on?

gel electrophoresis, a method that separates macromolecules—usually proteins or nucleic acids—on the basis of size, electrical charge, or other physical properties

what can automated PCR do, starting with a minute sample?

generate billions of copies of a DNA segment in just a few hours, producing enough DNA to allow a DNA profile to be constructed

what does a recently developed transgenic rice strain harbor?

genes for milk proteins that can be used in rehydration formulas to treat infant diarrhea, a serious problem in developing countries

what are some genes that have evolved faster in humans than in chimpanzees?

genes involved in defense against malaria and tuberculosis and a gene regulating brain size

in humans, what is a small amount of our total DNA (about 1.5%) contained in?

genes that code for proteins, tRNAs, or rRNAs

what is recombinant DNA technology widely used for today?

genetic engineering, the direct manipulation of genes for practical purposes

what do scientists compare when comparing DNA samples?

genetic markers, sequences in the genome that vary from person to person

what have scientists produced many different varieties of?

genetically modified organisms (GMOs), organisms that have acquired one or more genes by artificial means

what are many proteins that mammalian cells normally secrete?

glycoproteins, proteins with chains of sugars attached

what are two products made using recombinant cells?

human insulin and human growth hormone

what is one potential benefit of having a complete map of the human genome?

hundreds of disease-associated genes have been identified

what can a bacterial protein called Cas associated with the repeats do?

identify and cut viral DNA, thereby defending the bacterium against infection

what else is possible through using DNA technology as a diagnostic tool?

identify symptomless carriers of these and other diseases caused by recessive alleles

what does the Centers for Disease Control and Prevention regularly use DNA technology to do?

identify the precise strain of bacteria that is causing a food poisoning outbreak, allowing officials to announce and implement more stringent food safety measures

what does a specialized chemical technique enable electronic monitors to do?

identify which of the four nucleotides is being added, allowing determination of the sequence

what did associated software with the nanopore sequencer allow?

immediate identification and analysis of the sequence

when did modern humans first appear?

in Africa around 200,000 years ago and spread into Europe and Asia around 50,000 years ago—meaning that modern humans and Neanderthals most likely comingled for a long time

where is the Parkinson's/Alzheimer's gene also found?

in rats, where it plays a role in the sense of smell, and in zebra finches, where it is thought to be involved in song learning

how is a particular Cas protein called Cas9 similar to restriction enzymes?

in that it cuts double-stranded DNA molecules

what is DNA profiling based on?

indirectly identifying differences in nucleotide sequences by determining the numbers of STRs for various short tandem repeats

what do maps of a variety of genomes help scientists do?

interpret the human genome by comparison

what does about one quarter of our DNA consist of?

introns (noncoding stretches of nucleotides; see Module 10.10) and gene control sequences, such as promoters, enhancers, and microRNAs

what does a biologist do to begin gene cloning?

isolates two kinds of DNA: a bacterial plasmid (usually from the bacterium E. coli) that will serve as the vector, or gene carrier, and the DNA from another organism ("foreign" DNA) that includes the gene that codes for protein V (gene V) along with other, unwanted genes

what happens after a restriction enzyme binds to its restriction site?

it cuts both strands of the DNA at precise points within the sequence, yielding pieces of DNA called restriction fragments

what are the benefits of the whole-genome shotgun approach?

it is fast and relatively inexpensive

what happens to the recombinant plasmid containing the targeted gene?

it is mixed with bacteria

what is a risk of insulin from slaughtered pigs and cattle?

it is not identical to human insulin and can therefore cause allergic reactions in some people

why is vaccination so important for many viral diseases?

it is the only medical way to prevent illness

what happens once a genetically engineered animal is successfully produced?

it may be cloned

what might be possible in people afflicted with disorders caused by a single defective gene?

it might be possible to replace or supplement the defective gene by inserting a normal allele into that person's cells->Once there, the normal allele might be expressed, potentially offering a permanent cure after just one treatment

what happens when a harmless mutant is used as a live vaccine?

it multiplies in the body and may trigger a strong immune response

what happens when a radioactive probe is added to a collection of DNA strands?

it tags the correct molecules by hydrogen-bonding to the complementary sequence in the gene of interest

what does the enzyme DNA ligase then do?

joins the two DNA molecules by way of covalent bonds

what is the current estimate of the number of genes in the human genome?

just below 21,000

what can bacteria be engineered to produce?

large amounts of particular proteins and, in some cases, to secrete the proteins directly into their growth medium, simplifying the task of collecting and purifying the products

why do longer DNA fragments move more slowly than the shorter fragments?

longer DNA fragments are held back by the thicket of polymer fibers within the gel

what did molecular biologists do in 1985?

made an artificial gene for HGH

what do research laboratories, private companies, and government-funded agencies do?

maintain databases and provide software with which scientists can analyze sequence data

what have researchers created plants that do?

make human proteins for medical use

what are recombinant cells and organisms used to do?

manufacture gene products, chiefly proteins

what can scientists do through DNA cloning?

mass produce many useful products

what have scientists genetically engineered bacteria to do?

mass-produce a variety of useful chemicals, from cancer drugs to pesticides

what has the development of high-throughput sequencing techniques resulted in?

massive increases in speed and decreases in the cost of sequencing entire genomes

what did a 2015 study involve?

mice that carried a mutation in a gene that codes for dystrophin, a protein essential for muscle function

what do GMO advocates counter?

no lasting or detrimental effects from such transfers have been demonstrated and that some GMOs can actively help the environment

what did the researchers report about the pigs?

no significant differences between the two groups and no traces of foreign DNA in the slaughtered pigs

what is insulin?

normally secreted by the pancreas, is a hormone that helps regulate the levels of glucose in the blood

what did the gene now do (2015 study)?

now lacking the mutation, produced dystrophin proteins that functioned normally, which allowed the muscles in the mice to function properly

what does repetitive DNA consist of?

nucleotide sequences that are present in multiple copies in the genome; much of the DNA that lies between genes in humans is of this type

what are some plants that have been completely sequenced?

one type of mustard (Arabidopsis thaliana) and a strain of rice (Oryza sativa, one of the world's most economically important crops)

what does cDNA represent?

only the subset of genes that had been transcribed into mRNA in the starting cells

what have some genes for desired human proteins been inserted into?

other mammals->In some cases, the protein encoded by the recombinant gene may then be harvested from the recombinant animal's milk

what do genomes hold the key to?

our genetic identity

who must inject insulin daily?

people with type I diabetes

what happens to the people with the form of LCA that causes them to produce abnormal rhodopsin?

photoreceptor cells gradually die, causing progressive blindness

what does the filter paper do?

picks up cells from each colony

what can also be used to produce recombinant drugs?

plants

what do biologists often use to manipulate genes in the laboratory?

plasmids, small, circular DNA molecules that replicate (duplicate) separately from the much larger bacterial chromosome

what is S. cerevisiae currently used to do?

produce a number of proteins used in medicines, including the hepatitis B vaccine, an antimalaria drug, and interferons used to treat cancer and viral infections

in addition to using recombinant cells, what can pharmaceutical researchers also do?

produce gene products on a large scale through the use of whole animals or plants

what can a molecular biologist do by transferring the gene for a desired protein into a bacterium, yeast, or other kind of cell that is easy to grow in culture?

produce large quantities of useful proteins that are otherwise difficult to obtain

what are some uses of DNA profiling?

prove innocence and guilt, identify victims, paternity tests, probe the origin of nonhuman materials (contraband animal products),

what have modern DNA technology methods done?

rapidly transformed the field of forensics, the scientific analysis of evidence for crime scene investigations and other legal proceedings

what were molecular biologists able to create using lab-made HGH?

recombinant E. coli that produce HGH

in editing a gene, what happens after Cas9 cuts the target DNA?

repair enzymes use the normal DNA as a template to repair the target DNA at the break point

what does much of the DNA between genes consist of?

repetitive DNA, nucleotide sequences present in many copies in the genome

what does the recombinant bacterium then do?

reproduces through repeated cell cycles to form a clone of cells, a population of genetically identical cells

what can law enforcement agencies around the world access CODIS to do?

search for matches to DNA samples they have obtained from crime scenes or suspects

what did scientists do in 2013?

sequenced the entire genome of a 130,000-year-old female Neanderthal found in a Siberian cave by analyzing DNA extracted from her toe bone

what is "high-throughput" DNA technology?

sequencing more than 2 billion nucleotides in one day

what have other mammals been modified to do?

serve as models for human diseases or to improve the health of livestock

what do scientists think that a typical human gene specifies?

several different polypeptides

what can critics of GMO crops point to?

several studies that do indeed show unintended gene transfer from engineered crops to nearby wild relatives

what does the repetitive DNA used in DNA profiles consist of?

short sequences repeated many times in a row; such a series of repeats is called a short tandem repeat (STR)

what may a researcher investigating a gene search for on BLAST?

similar regions in other genes of the same species or among the genes of other species

Since around 2001, what have "next-generation sequencing techniques been developed that can do?

simultaneously sequence thousands or hundreds of thousands of DNA fragments, each of which is typically 300 nucleotides long

before 1982, what were the main sources of insulin?

slaughtered pigs and cattle

what do the sequences of the first human genome to be sequenced and the biotechnology company's president serve as?

standards so that comparisons of individual differences and similarities can be made

what is "high-throughput" DNA technology the method of choice for?

studies where massive numbers of DNA samples—even representing an entire genome—are being sequenced

what must scientists do because proteins, not genes, actually carry out most of the activities of the cell?

study when and where proteins are produced in an organism and how those proteins interact to understand how cells and organisms function

what did further analysis of the female neanderthal reveal?

that Neanderthals and Homo sapiens interbred

what does analysis of the lactase gene suggest?

that Neanderthals, like the majority of modern humans, were lactose intolerant as adults

what did an analysis of chimp and human DNA reveal?

that a third of the human duplications are not present in the chimpanzee genome, and some of these duplications contain regions associated with human diseases

what did a 2014 study reveal?

that many present-day humans of European and Asian descent obtained Neanderthal-derived genes around 70,000 years ago that influence the production of keratin, a protein that is a structural component of hair, nails, and skin

what did the chinese schoolchildren project leaders argue against the uproar?

that proper permission and consent had been obtained in both China and the United States

what do some biotechnology advocates believe?

that similar demands were not made when "transgenic" crop plants produced by traditional breeding techniques were put on the market

what do comparisons of chimp and human DNA reveal?

that the genomes differ by only 1.2% in single-base substitutions, with a further 2.7% difference due to insertions or deletions of larger regions in the genome

what have cross-species comparisons revealed?

that the genomes of humans, rats, and mice contain almost 500 regions of noncoding DNA that are identical in sequence in all three species->this suggests that noncoding regions have important functions

what do Labeling advocates point out?

that the information would allow consumers to decide for themselves whether they wish to be exposed to GMO foods

what do advocates of a cautious approach toward GMO crops fear?

that transgenic plants might pass their new genes to related species in nearby wild areas, disturbing the composition of the natural ecosystem

what is a powerful new technique for gene editing?

the CRISPR-Cas9 system

what may differences between the FOXP2 gene in human and chimpanzee DNA play a role in?

the ability of humans, but not chimpanzees, to communicate by speech

what do mammals proved?

the cells of choice for making some gene products

what can happen once the researcher identifies a colony carrying the desired gene?

the cells of that colony can be grown further, and the gene of interest, or its protein product, can be collected in large amounts

what will ideally happen to the cells?

the cells will multiply throughout the patient's life and produce a steady supply of the protein, curing the patient

what do the single-stranded ends of the plasmid base-pair with?

the complementary ends of the target DNA fragment

what has the need to collate and analyze the flood of sequence data pouring in from genome projects led to?

the development of bioinformatics, the application of computational methods to the storage and analysis of biological data

what is one of the most significant advances in DNA technology in recent years?

the development of techniques that allow specific genes to be edited within living cells

what was a key prerequisite for automating PCR?

the discovery of an unusual DNA polymerase, first isolated from a bacterium living in hot springs, that could withstand the heat at the start of each cycle

what was the biggest surprise from the HGP?

the discovery that the human genome contains a comparatively low number of genes

what happens in each type of base in third-generation sequencing?

the electrical current is interrupted for a slightly different length of time, allowing the base sequence to be determined nucleotide-by-nucleotide

in 1995, what did a team of scientists determine the nucleotide sequence of?

the entire genome of Haemophilus influenzae, a bacterium that can cause several human diseases, including pneumonia and meningitis

what does comparative analysis provide invaluable insights into?

the evolutionary relationships among organisms

what do other sequenced animals include?

the fruit fly (Drosophila melanogaster) and the laboratory mouse (Mus musculus)

what can altering the nucleotide sequence of a gene inside a living cell reveal?

the function of the gene or even correct genetic mutations that cause disease

what has a gene for antithrombin—a human protein that helps prevent improper blood clotting—been inserted into?

the genome of a goat->The protein is later isolated from the animal's milk and then injected into patients, reducing the risk of life-threatening blood clots during surgery or childbirth

what did researchers complete in 2005?

the genome sequence for our closest-living relative on the evolutionary tree of life, the chimpanzee (Pan troglodytes)

in the 1970s, what was the field of biotechnology advanced by?

the invention of methods for making recombinant DNA in the lab

what is biotechnology?

the manipulation of organisms or their components to make useful products

the more similar in sequence the same gene is in two species...

the more closely related those species are in their evolutionary history

what did the virus infect (2015 study)?

the muscle cells of the mice and removed a region of the gene containing the dystrophin mutation

what would have to happen for gene therapy to be permanent?

the normal allele would have to be transferred to cells that multiply throughout a person's life

what are major advantages of bacteria?

the plasmids available for use as gene-cloning vectors and the fact that bacteria can be grown rapidly and cheaply in large tanks

what were early concerns about DNA technology focused on?

the possibility that recombinant DNA technology might create new pathogens

what is one reason to tamper with the human genome?

the potential of gene therapy—alteration of a diseased individual's genes for therapeutic purposes

what is the key to the high sensitivity of PCR?

the primers

what is another purpose of gene cloning?

the protein product of the cloned gene is harvested and used

what is the first step of each PCR cycle?

the reaction mixture is heated to separate the strands of the DNA double helices

what was the first multicellular organism to have its full sequence determined?

the roundworm Caenorhabditis elegans

what is one approach to vaccine production?

the use of genetically engineered cells or organisms to produce large amounts of a protein molecule that is found on the pathogen's outside surface

what is the key to amplifying one particular segment of DNA and no others?

the use of primers, short (usually 15-20 nucleotides long), chemically synthesized single-stranded DNA molecules with sequences that are complementary to sequences at each end of the target sequence

What are some examples of biotechnology?

the use of yeast to make beer and bread, and the selective breeding of livestock, dogs, and other animals

what has the method of using genetically engineered cells to produce vaccines been used to make?

the vaccine against hepatitis B, a disabling and sometimes fatal liver disease

in the US today, what are some examples of GMOs?

the vast majority of corn, soybean, cotton, and other staple products

what did scientists notice within bacterial genomes?

there were short repetitive DNA sequences with different stretches of "spacer DNA" between the repeats

what happens to the cut DNA from both sources?

they are mixed

what then happens to the DNA strands?

they are soaked in probe solution

once cut, what can happen to restriction fragments of DNA?

they can be pasted together by the enzyme DNA ligase

what is one application of nucleic acid probes?

they can be used in DNA microarrays to test the expression of many genes at once

what did scientists announce in 2015?

they had transferred 23 genes (from bacteria, plants, and animals) into yeast that allow the recombinant fungi to convert sugar into the painkiller drug hydrocodone

What will happen to any bacterial colonies carrying the gene of interest?

they will be tagged on the filter paper, marking them for easy identification

what was the first nanopore sequencer on the market?

this device is the size of a small candy bar and connects to a computer via a USB port

what do completed genomes include?

thousands of bacterial species (some of medical importance), more than 200 Archaea, and hundreds of eukaryotic species, including fungi, plants, and animals

what are recombinant mammalian cells growing in labaratory cultures currently used to produce?

tissue plasminogen factor (TPA), a drug administered after heart attacks

what is another way to use DNA technology in vaccine development?

to make a harmless, artificial mutant of the disease-causing pathogen by altering one or more of its genes

what is the idea of third-generation sequencing?

to move a single strand of DNA through a very small pore in a membrane (a nanopore) while administering an electrical current that will detect the nitrogenous bases one by one

how else have scientists used genetic engineering?

to transfer genes from bacteria into plants and from one animal species to another

what did molecular biologist J. Craig Venter do several years into the project?

took a different path when he set up a company (Celera Genomics) to sequence the entire human genome using an alternative strategy called the whole-genome shotgun method

what can DNA analysis help do?

track down and identify elusive viruses, such as HIV, which causes AIDS

what do most of the sequences in the second type of repetitive DNA seem to be associated with?

transposable elements ("jumping genes"), DNA segments that can move from one location to another in a chromosome and even between chromosomes

what does the biologist do after isolating the DNA in gene cloning?

treats both the plasmid and the gene V source DNA with an enzyme that cuts DNA

what does a scientist do to create a DNA profile?

uses PCR to specifically amplify the regions of DNA that include these STR sites

what does a newer strain of Golden Rice do?

uses corn genes to boost beta-carotene levels even higher

what do other pharmaceutical trials under way involve?

using modified corn to treat cystic fibrosis and duckweed to treat hepatitis

when do the ethical questions regarding gene therapy become much trickier?

when researchers contemplate the genetic manipulation of gamete-forming cells or zygotes, feats already accomplished in lab animals

how is Cas9 different from restriction enzymes?

while a given restriction enzyme recognizes only one particular DNA sequence, the Cas9 protein will cut any sequence to which it is directed by a molecule of RNA

how can a whole animal be produced?

with recombinant gene transfer when doing so is the only or optimal way to manufacture a needed pharmaceutical

what are some advantages of using yeast for protein production?

yeast cells are easy to grow, yeast cells are often better than bacteria at synthesizing and secreting eukaryotic proteins