102 terms

Chapter 15

Personal DNA testing?
identify a person's unique array of single-nucleotide polymorphisms - SNPs
This chip reveals which versions of 906,600 SNPs occur in the individual's DNA
Bacterial enzyme used to cut specific nucleotide sequences in DNA
restriction enzyme
Cloning DNA?
-Researchers use restriction enzymes to cut up DNA, then bond the fragments together using DNA ligase
-Fragments with complementary tails ("sticky ends") stick together when their matching tails base-pair
A DNA molecule that contains genetic material from more than one organism
recombinant DNA
DNA fragments from different organisms combine to make a hybrid molecule: recombinant DNA
Set of procedures that uses living cells to make many identical copies of a DNA fragment
DNA cloning
Of many bacteria and archaeans, a small ring of nonchromosomal DNA replicated independently of the chromosome
A DNA molecule that can accept foreign DNA, be transferred to a host cell, and get replicated in it
cloning vector
A viral enzyme that uses mRNA as a template to make a strand of cDNA
reverse transcriptase
DNA synthesized from an RNA template by the enzyme reverse transcriptase
Collection of cells that host different fragments of foreign DNA, often representing an organism's entire genome
DNA library
An organism's complete set of genetic material
- Short fragment of DNA labeled with a tracer such as a radioactive isotope
- Designed to hybridize with a nucleotide sequence of interest
Base-pairing between DNA or RNA from different sources
nucleic acid hybridization
Method that rapidly generates many copies of a specific section of DNA
polymerase chain reaction (PCR)
(The polymerase chain reaction (PCR) uses primers and heat-resistant DNA polymerase to mass-produce a particular section of DNA without having to clone it in living cells)
Short, single strand of DNA designed to hybridize with a DNA fragment
DNA libraries, hybridization, and PCR are techniques that allow researchers to isolate and make many copies of a fragment of DNA they want to study
Finding Needles in Haystacks
DNA sequencing?
-Method of determining the order of nucleotides in DNA
-DNA polymerase partially replicates a DNA template
-Produces a mixture of DNA fragments of different lengths
-Fragments are separated by electrophoresis
Technique that separates DNA fragments by size
How does electrophoresis work?
Electrophoresis separates fragments by length into bands
Electric field pulls DNA fragments through semisolid gel
Fragments of different sizes move at different rates
Shorter fragments move through the gel faster than longer fragments do
How may bases does the human genome consist?
about 3 billion bases
Who invented the faster methods of sequencing genomic DNA using supercomputers?
Craig Venter's company, Celera Genomics
When was the human genome sequence completed?
By 2003
What does DNA sequencing do?
- Sequencing reveals the linear order of nucleotides in DNA
- Comparing genomes offers insights into human genes and evolution
- An individual can be identified by unique parts of their DNA
-The study of genomes
-Includes whole-genome comparisons, structural analysis of gene products, and the study of small-scale variation
(provide insights into human genome function)
Identifying an individual by analyzing the unique parts of his or her DNA
DNA profiling
In chromosomal DNA, sequences of 4 or 5 bases repeated multiple times in a row
short tandem repeats
Process by which deliberate changes are introduced into an individual's genome
genetic engineering
Organism whose genome has been modified by genetic engineering
genetically modified organism (GMO)
(Bacteria have been modified to produce medically important proteins such as insulin)
Refers to a genetically modified organism that carries a gene from a different species
Researchers use _______ from bacteria as a vector to transfer foreign or modified genes into food crop plants such as soybeans, squash, and potatoes
a Tumor-inducing (Ti) plasmid
The most widely planted GMO crops?
corn, sorghum, cotton, soy, canola, and alfalfa
What do people call GMO crops?
Genetically modified (GM) animals are invaluable in medical research and other applications
Biotech Barnyards
Transplantation of an organ from one species into another
(Genetically modified animals may one day provide compatible organs and tissues for xenotransplantation into humans)
Transfer of a recombinant DNA into an individual with the goal of treating a genetic defect or disorder
Inserts an unmutated gene into an individual's chromosomes
gene therapy -- is now being tested as a treatment for heart attack, sickle-cell anemia, cystic fibrosis, hemophilia A, Parkinson's and Alzheimer's diseases, several cancers, and inherited diseases of the eye, ear, and immune system
______ is a severe X-linked disorder of the____, which codes for an immune-system receptor protein
(Affected children can't fight infections)
SCID-X1, IL2RG gene
Side effects of Gene therapy?
- Cancer can result
- Organs shut down and die
Idea of deliberately improving the genetic qualities of the human race
All human beings share approximately ________% of their DNA with the rest of the human population.
The genetic variation that exists among humans is mainly due to the differences that exist within their ________.
Which structure will restrict the growth of viruses?
Restriction enzymes
During genetic engineering small loops of DNA called ________ need to be shuffled from one organism to another.
A fragment of DNA or RNA, labeled with a tracer, used for genetic studies is called a ________.
Which technique is used to mass produce copies of a section of DNA outside of a cell?
Polymerase chain reaction
During ________ DNA fragments are separated based upon ________.
electrophoresis, size
When was the human genome officially sequenced?
What field of science compares the genomes of different organisms?
Chromosomes will break at particular spots and undergo several translocations. Which species has not undergone chromosome breakage and translocations?
All have undergone breakage and translocations: . Cows, Humans, Mice and Pigs
________are the most genetically modified organisms used by scientists.
________ is the process by which an organism's genome is deliberately modified.
Genetic engineering
What type of pressure is not placed upon the environment as crop production expands?
Additional habitat available for many species.
What product is being produced by genetically engineered golden rice?
B carotene
Which species is a potential source of organ transplantation to humans?
Which animals were the 1st to be genetically modified?
A challenge with scientific breakthroughs is that they are rarely accompanied by ________.
the discovery of the tools to study them
One of the main safety guidelines of DNA research is that ________.
the host organisms can only survive under a narrow range of laboratory conditions
________ is the transfer of recombinant DNA into an individual's body in an attempt to correct a genetic defect.
Gene therapy
Which is a risk that must be assumed when we genetically engineer a living individual?
Cancer may be the result of the inserted gene.
Development of an allergic reaction to the viral vector.
On which chromosome will the virus integrate the injected gene.
The inserted gene may disrupt the normal genetics of the

All are risks associated with gene therapy.
___ cut(s) DNA molecules at specific sites
Restriction Enzymes
A ____ is a small circle of bacterial DNA that contains a few genes and is separate from the chromosome
By reverse transcription, ____ is assembled on a(n) ____ template
For each species, all ____ in the complete set of chromosomes is the ____
DNA, genome
A set of cells that host various DNA fragments collectively representing an organism's entire set of genetic information is a_____
Genomic library
___ is a technique to determine the order of nucleotide bases in a fragment of DNA
DNA sequencing
Fragments of DNA can be separated by electrophoresis according to _____
PCR can be used
- To increase the number of specific DNA fragments
- in DNA fingerprinting
An individual's set of unique ____ can be used as a DNA profile
DNA sequences
Short tandem repeats
All above are correct
Which of the following can be used to carry foreign DNA into hose cells?
Lipid clusters
Blasts of pellets
A transgenic organism_____
- carries a gene from another species
- has been genetically modified
____ can be used to correct a genetic defect
gene therapy
Taq polymerase
cutting DNA
restriction enzyme
cDNA synthesis
reverse transcriptase
DNA sequencing
DNA polymerase
pasting DNA
DNA ligase
DNA fingerprint
a person's unique collection of short tandem repeats
Ti plasmid
used in some gene transfer
nucleic acid hybridization
base-pairing of DNA or DNA and RNA from different sources
selecting "desirable" traits
Single-nucleotide polymorphism
- alleles have them
- a nucleotide difference carried by a measurable percentage of a population, usually above 1 percent
having a foreign gene
genetically modified
About _____ percent of an individual's genes are the same as in the general population.
Restriction enzymes
- often produce staggered cuts in DNA that are useful in splicing genes.
- are like most enzymes in being very specific in their action.
- are natural defense mechanisms evolved in bacteria to guard against or counteract bacteriophages.
- are used along with ligase and plasmids to produce a DNA library.
Which of the following enzymes join the paired sticky ends of DNA fragments?
DNA ligase
- are self-reproducing circular molecules of DNA.
- are sites for inserting genes for amplification
- may confer the ability to donate genetic material when bacteria conjugate.
Because it has no introns, researchers prefer to use ____ when working with human genes.
RNA can manufacture DNA via the action of____
reverse transcriptase
cDNA is copied from___
Probes for cloned genes use___
complementary nucleotide sequences labeled with radioactive isotopes.
A collection of cells containing DNA fragments produced by restriction enzymes and incorporated into plasmids is called_____
a DNA library.
For the polymerase chain reaction to occur,_____
isolated DNA molecules must be primed, and the DNA must be separated into single strands.
The polymerase used in PCR was isolated from_____
Thermus aquaticus. Living in Hot Springs
The laboratory technique used to separate the DNA fragments produced by automated DNA sequencing is____
gel electrophoresis.
What is the purpose of the modified bases in DNA sequencing?
- DNA replication terminates when a modified base is added.
- They are easily recognized by the computer.
- They are added to the DNA chain just like the normal bases.
DNA fingerprinting is based on the slight differences that occur in ____ in the human genome.
short tandem repeats
E. coli that contains the genes for human insulin is____
- genetically engineered.
- transgenic.
- a GMO.
Bacteria have been engineered to___
- produce chymotrypsin.
- make human insulin.
- produce enzymes that increase shelf life of bread.
- produce enzymes that improve the taste and clarity of beer.
The Ti plasmid from which plant pathogen is used to transfer plant genes between species?
Agrobacterium tumefaciens
In 1972, Paul Berg and his colleagues were the first to make____
recombinant organisms.
Which of the following statements is false? NIH safety guidelines
have so far prevented accidental release of all GMOs.
In the SCID-X1 gene therapy trials, what problem later surfaced in three of the patients?
leukemia - a type of bone marrow cancer