Which of the following is an example of "recombinant DNA technology?
introducing a human gene into a bacterial plasmid; Recombinant DNA technology involves combining DNA from different sources into a single molecule, such as inserting a gene from one species into a plasmid from another.
In recombinant DNA experiments, what is used to cut pieces of DNA and what joins the resulting fragments to form recombinant DNA?
a restriction enzyme ... DNA ligase; Restriction enzymes cut DNA molecules at specific points; in most cases, the restriction fragments have sticky ends that can base-pair with complementary sticky ends. The joined segments are then covalently fused by DN
Which of the following tools of recombinant DNA technology is incorrectly paired with its use?
DNA ligase-cutting DNA, creating sticky ends of restriction fragments
In recombinant DNA methods, the term vector can refer to
a plasmid used to transfer DNA into a living cell.
A researcher is preparing to insert a human gene of interest into a bacterial plasmid in order to clone the human gene. She has genetically engineered the plasmid to carry a gene amp R , which confers resistance to the antibiotic ampicillin. She will incl
Recombinant bacteria that have taken up the plasmid can be recognized because they are able to survive in the presence of ampicillin.
Which "ingredients" for PCR and for the dideoxy chain-termination method of DNA sequencing are the same?
free nucleotides, DNA polymerase, DNA primers; If DNA polymerase encounters a DNA template strand with a primer attached to it, and free nucleotides are available, DNA synthesis will proceed.
cDNA is synthesized from what molecule using an enzyme known as what?
mRNA ... reverse transcriptase; Reverse transcriptase is a viral enzyme that can synthesize DNA from an RNA template.
Gel electrophoresis separates DNA fragments on the basis of what characteristic?
length; As the DNA fragments move through the gel, longer fragments are impeded more than shorter fragments, producing characteristic banded patterns in the gel.
If a restriction enzyme is combined with a piece of DNA that contains its restriction site, the result will be restriction fragments.
A restriction site on a piece of DNA contains the specific base sequence that is recognized by the restriction enzyme. Once the cut is made, the resulting smaller pieces are called restriction fragments.
To create a molecule of DNA, which of the following is cut with a restriction enzyme?
To create a molecule of recombinant DNA, both the target DNA (shown in red in the figure) and the starting DNA (blue) are cut with the same restriction enzyme. This allows the sticky ends to hydrogen bond into the final recombinant DNA molecule.
To make r
Cloning a Gene in Bacteria
We can use the techniques of DNA technology to recombine and copy genes. A restriction enzyme is used to cut open a plasmid, a small circular DNA molecule obtained from a bacterium. The plasmid serves as a cloning vector. The restriction enzyme cuts only
What enzyme forms covalent bonds between restriction fragments?
DNA ligase-catalyzes the formation of covalent bonds between restriction fragments.
Transformation
Transformation is the process by which a bacterium takes up a plasmid from the surrounding solution.
cloning
Cloning occurs with the replication of a recombinant plasmid.
The unpaired nucleotides produced by the action of restriction enzymes are referred to as
They are called sticky ends since they will "stick" to a complementary single-stranded sequence.
what information can not be obtained from the sequence of a gene?
Whether the gene is methylated. Although the gene's sequence may reveal the presence of methylation targets like cytosine (C), it does not give information about whether such bases have been methylated.
What is the polymerase chain reaction (PCR)?
A method to amplify a fragment of DNA. PCR is an in vitro DNA synthesis reaction that produces many copies of a single DNA fragment.
Comparison of the sequences of the same gene across species can give some insight into the existence of a common ancestor with that gene.
true; DNA sequence comparisons are a powerful tool by which to estimate how closely related different species are along the evolutionary timeline.
True or false? The Taq enzyme is a type of DNA polymerase that allows researchers to separate the DNA strands during the annealing step of the PCR cycle without destroying the polymerase.
false; Taq polymerase is derived from a species of bacteria living in hot springs, which makes it stable at the high temperature required for the denaturation step of PCR.
How many DNA molecules would there be after four rounds of PCR if the initial reaction mixture contained two molecules?
32; Thirty-two DNA molecules are produced if two molecules are doubled four times.
During which step in the PCR cycle are nucleotides used?
extension; Nucleotides are used to synthesize the complementary strand to the DNA template during the extension step.
During which step in the PCR cycle do primers form bonds with a single-stranded template?
annealing; Primers form hydrogen bonds with the single-stranded DNA template during the annealing step.
Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. How could they obtain sufficient DNA for an analysis of the ancient human's genes?
Use the polymerase chain reaction. PCR is a method of DNA amplification.
You are a member of the jury for a murder case. The prosecution has presented DNA evidence linking the defendant to the crime scene. The defense claims that DNA evidence using STR analysis with 13 markers is not sufficient to reliably distinguish between
The prosecution is right. STR analysis with 13 markers gives a 1 in 10 billion or greater chance that two people will have the same pattern. This person was at the crime scene. Given the current population of the Earth, STR analysis with 13 markers should
A paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo (a bird). To compare a specific region of the DNA from the sample with DNA from living birds, which of the following would be most useful for increasing
polymerase chain reaction (PCR)
Which of the following would not be true of cDNA produced using human brain tissue as the starting material?
It could be used to create a complete genomic library
Expression of a cloned eukaryotic gene in a bacterial cell involves many challenges. The use of mRNA and reverse transcriptase is part of a strategy to solve the problem of
post-transcriptional processing.
Cold case detectives are investigating a homicide that took place 30 years ago. In reexamining the evidence, they find a tiny spot of blood on the victim's clothing that was likely left by the murderer. The DNA in the blood has partially degraded over tim
They would use PCR to amplify the DNA. PCR is impressive in the speed and specificity with which it amplifies DNA. Only minute amounts of DNA need be present in the starting material, and this DNA can be in a partially degraded state, as long as a few mol
what defect causes pituitary dwarfism?
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