chap 9 Flashcards
What is the end goal of PCR?
To quickly increase the number of copies of a specific DNA sequence
PCR stands for
polymerase chain reaction.
an application that uses PCR?
Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism
function of the primers in PCR?
hey provide a 3’ end for the DNA polymerase.
In which direction does DNA polymerase synthesize the new DNA strand?
5’ to 3’
What provides the energy for DNA polymerization in a PCR reaction?
Deoxyribonucleoside triphosphates
Why is DNA polymerase from Thermus aquaticus ideal for PCR?
It can withstand the high temperatures associated with PCR.
What is the temperature used for the extension step?
72 °C
How do the strands separate during PCR?
The high heat of the denaturation step breaks the hydrogen bonds between the two strands.
What is a thermocycler?
The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR
what is the sequence of the temperatures of a typical PCR reaction?
94 °C, 60 °C, 72 °C
If you used a broken thermocycler that could not heat above 75°C, which of the following problems could you expect?
You would not get any amplification of DNA.
The DNA strands would never separate, thus no amplification would occur.
Which of the following provides the specificity of the PCR reaction? A. primers B. Taq polymerase C. heating to 94°C D. separated DNA strands
primers
Primers bind to specific regions of the DNA and determine which area(s) will be amplified.
A new arrow labeled “lengthens” could be added between __________.
“Taq polymerase” → “primers”
How do restriction enzymes cut DNA sequences?
They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.
how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene?
To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene
To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene
DNA ligase
Why would a recombinant (genetically engineered) DNA molecule be inserted into a host cell?
It can be copied, transcribed, and translated into a desired protein.
Which statement best describes restriction enzymes?
Which statement best describes restriction enzymes?
property of useful vectors?
- They must be able to self-replicate.
- They must be small enough to allow them to be manipulated prior to injection.
- They must have properties that allow their survival in the host cell.
Foreign DNA can be inserted into cells using a variety of different methods. Which method involves the formation of microscopic pores in the cell’s membrane?
electroporation
Why is baker’s yeast useful for expressing genetically engineered genes?
Yeast cells are eukaryotic and so would likely be successful in expressing eukaryotic genes.
methods could be used to identify the source of an outbreak?
DNA fingerprinting
Recombinant DNA technology is commonly used to move DNA from one type of cell to another.
- It allows researchers to make protein products of a gene.
- It can be used to screen individuals for many different types of genetic diseases.
- It allows researchers to make many copies of a gene of interest.
Which of the following applications of recombinant DNA technology is NOT controversial (argument) ?
A. biological weapons development
B. genetic food modification
C. genetic screening
D. metagenomics
D. metagenomics=study of the structure of nucleotide sequences
You’d like to make a fluorescent bacterium (!). the correct sequence of procedures that you would use?
- Amplify the gene using PCR.
- Insert the gene into a plasmid vector.
- Transform the vector into the bacteria.
foreign genes can be inserted into plant cells
A. Scientists have created plants that are resistant to herbicides by using a mutant enzyme gene from Salmonella.
B. Scientists have created plants that produce an insect toxin originally found in bacteria.
D. Scientists have used gene silencing to create tomatoes with a longer shelf life.
The reaction catalyzed by reverse transcriptase is
mRNA → cDNA.
Biotechnology involves the
use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistanct crop plants.
The Human Genome Project, which was completed in 2003, was focused on
determining the nucleotide sequence of the entire human genome.
Self-replicating DNA used to transmit a gene from one organism to another is a
vector.
In the Southern blot technique,
A. restriction enzyme digestion of DNA
B. electrophoresis to separate fragments
C. transfer of DNA to nitrocellulose
D. addition of a labeled probe to identify the gene of interest
The Pap test for cervical cancer involves microscopic examination of cervical cells for cancerous cells. A new, rapid diagnostic test to detect human papilloma virus (HPV) DNA before cancer develops is done without microscopic exam. The steps involved in this FastHPV test are listed below. What is the second step?
A. add enzyme substrate.
B. Add enzyme-linked antibodies against DNA-RNA.
C. Lyse human cells.
D. Add an RNA probe for HPV DNA.
E. The order is unimportant.
Add an RNA probe for HPV DNA.
