Chapter 8 HW Microbiology
Which of the following statements regarding vectors is FALSE?
-Vectors are generally over 100,000 base pairs in size. A useful vector contains multiple restriction sites for insertion of DNA. Cloning vectors frequently contain sequences necessary for expression of inserted sequences. Vectors are usually autonomously replicating DNA molecules. Cloning vectors include a "marker" to facilitate identification of cells containing them.
Which of the following is NOT a goal of recombinant DNA technology?
-making it possible to clone humans eliminating undesirable traits from livestock or crops being able to remove or correct damaging traits in humans creating organisms capable of producing useful products combining genetic material from more than one organism to produce new useful organisms
If all the following DNA fragments were analyzed on an electrophoresis gel, which one would migrate farthest from the negative electrode?
250 base pairs
What is the temperature used for the extension step?
72 °C
What is the sequence of the temperatures of a typical PCR reaction?
94 °C, 60 °C, 72 °C
Which of the following statements concerning sticky-ended fragments is most likely to be true?
Complementary sticky-ended fragments were probably cut by the same restriction enzyme.
Which of the following attaches the target gene to a desired location?
DNA ligase
Synthetic nucleic acids are useful as
DNA probes, primers, and antisense RNAs.
If a researcher used Escherichia coli DNA polymerase instead of Thermus aquaticus DNA polymerase in the PCR procedure, what would be the result?
DNA replication would stop after one cycle.
How are restriction enzymes named?
Each is named with letters referring to the genus, species, and strain of the source prokaryote and a Roman numeral denoting the order of its discovery.
Why would a recombinant DNA molecule be inserted into a host cell?
It can be copied, transcribed, and translated into a desired protein.
To men may be the father of a child. the figure shows the results of a DNA fingerprint analysis to determine paternity. M is the mother, C is the child, A and B are the two men. What is the best interpretation of these results?
The man identified as B is probably the father.
All restriction sites are palindromic. What does this mean?
The nucleotide sequences at the restriction sites are the same when read forward or backward.
What process is used to "amplify" DNA, making large numbers of copies from a small sample?
Polymerase chain reaction
A researcher inserted DNA fragments from an organism into expression vector plasmids and introduced the modified plasmids into bacterial cells. Which of the following methods would be an effective means of identifying which clones contain a specific gene of interest?
Prepare and analyze restriction fragments of the plasmids.
A researcher mistakenly uses a heat-sensitive version of DNA polymerase in a PCR. Which of the following will occur?
The PCR will stop after one cycle.
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
How do restriction enzymes cut DNA sequences?
They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.
What action do restriction enzymes employ?
They cut DNA.
What role do restriction enzymes serve in the prokaryotes that produce them?
They destroy viral DNA.
Which of the following is NOT a reason why human proteins can be synthesized in bacteria or yeast through genetic engineering?
This approach is usually less expensive than traditional methods. -The protein produced by microbes works better than the original protein. Large quantities of the protein can be made easily. There is no risk of accidentally transferring pathogens.
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
Which of the following devices is used for PCR?
a thermocycler
Which of the following is generally NOT considered an ethical issue regarding recombinant DNA technology?
answering basic research questions
Subunit vaccines are safer than traditional vaccines because they
are acellular and do not pose a risk for causing the disease.
The restriction enzyme KpnII probably originated __________.
as the second discovered restriction enzymes from Klebsiella pneumoniae bacterium
What is the function of the high temperature step in PCR (polymerase chain reaction)?
break hydrogen bonds for strand separation
Put the following events in the construction of a recombinant DNA molecule in the correct order: a. ligation of desired gene to plasmid DNA b. introduction of the plasmid into bacteria c. restriction enzymes cut gene of interest and plasmid DNA d. growth of cells on an antibiotic-containing medium
c, a, b, d
Double strand DNA fragments are separated by size using
gel electrophoresis.
DNA encoding a normal gene is inserted into cells from a patient with a defective form of the gene. Recombinant cells are identified and isolated, and returned to the patient's body. This is an example of
gene therapy.
Replacing a patient's defective gene with a fragment containing a functional gene is
gene therapy.
Single-strand DNA molecules are fixed to a glass slide or nylon membrane for the production of
microarrays.
Which of the following is a product of recombinant DNA technology?
microbes that produce vitamins, insulin and vaccines
Some of the strongest opposition to the application of recombinant DNA technology concerns
modification of food crops.
Mutagens are useful in biotechnology research for
producing organisms with altered phenotypes
Which of the following enzymes can make specific cuts in DNA molecules?
restriction enzymes
Although blunt-ended DNA fragments are more difficult to join back together than are sticky ends, blunt ends have an advantage in that __________.
they can be recombined with blunt fragments produced by different restriction enzymes
In the laboratory, recombinant DNA technologists use restriction enzymes __________.
to cut specific genes from one organism for the purpose of inserting the genes into the DNA of another organism
What is the name of genetic tools that can deliver genes into a cells?
vectors
