Chapter 9 (Homework + Voicethread)
What is the end goal of PCR?
To quickly increase the number of copies of a specific DNA sequence
Why is DNA polymerase from Thermus aquaticus ideal for PCR?
it can withstand the high temperatures associated with PCR
How can genomes from microbes that are not able to grow in the lab still be studied?
metagenomics
PCR stands for
polymerase chain reaction
They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences.
restriction enzymes
Explain how DNA replication and PCR are similar.
--Both synthesize DNA --5' to 3' direction --Double stranded DNA is separated in both with template strand
Describe key features of a restriction enzyme.
--cuts DNA sequences at recognition sites between nucleotides --can create sticky ends or blunt ends
Vector properties
--mostly contain more than one gene --allows them to survive in host cells --self-replication --small enough to be manipulated
In which direction does DNA polymerase synthesize the new DNA strand?
5' to 3'
Which statement regarding agricultural biotechnology is FALSE?
Agricultural biotechnology is extremely limited because foreign genes cannot be inserted into plant cells.
Scientists like to use fluorescent proteins for various types of recombinant DNA procedures. You have a very small amount of the gene for a fluorescent protein. You'd like to make a fluorescent bacterium. Which of the following represents 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.
Which of the following best describes how recombinant DNA technology currently helps patients who do NOT produce adequate amounts of growth hormone (hGH)—a condition that otherwise leads to stunted growth?
Bacteria now produce hGH.
Why is a vector is used in genetic modification procedures?
Cells usually won't copy an isolated gene sequence.
Which of the following methods could be used to identify the source of an outbreak?
DNA fingerprinting
Which of the following pairings of recombinant DNA techniques and applications does NOT match?
Gene silencing; production of subunit vaccines Gene silencinguses siRNA to silence expression of a gene.
Why would a recombinant DNA molecule be inserted into a host cell?
It can be copied, transcribed, and translated into a desired protein.
Which of the following statements about recombinant DNA technology is FALSE?
It has limited application because genes of interest cannot be moved from one type of cell to another.
Recombinant DNA techniques typically involve generating a clone. Why?
Producing a clone generates many copies of the gene of interest.
Which of the following is an application that uses PCR?
Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism
How do restriction enzymes cut DNA sequences?
They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.
What is the function of the primers in PCR?
They provide a 3' end for the DNA polymerase.
Which of the following best describes a clone in the context of genetic modification procedures?
a culture of genetically identical cells
Subunit vaccines
consisting only of a protein portion of a pathogen, made by genetically modifying yeasts.
What provides the energy for DNA polymerization in a PCR reaction?
deoxyribonucleoside triophosphates
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
How is cDNA made?
from mRNA by reverse transcriptase
Which technology uses DNA probes to detect DNA fragments?
southern blotting
Which of the following attaches the target gene to a desired location?
DNA ligase
In general, 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
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.
What does a vector, like PUC19, contain in order to easily take an insert and transform a cell?
it can self-replicate, it's size can be small to be manipulated, DNA molecule's circular form protects vector DNA. Foreign DNA can be inserted at the restriction enzyme sites.
Which of the following applications of recombinant DNA technology is NOT controversial?
metagenomics study of DNA from environmental samples