Chapter 9 and 10 Quiz

What provides the energy for DNA polymerization in a PCR reaction

Deoxyribonucleoside triphosphate

When a patient is treated with antibiotics,

the drug will kill or inhibit the growth of all the sensitive bacterial cells.

In which direction does DNA polymerase synthesize the new DNA strand?

5' to 3'

What is the temperature used for the extension step?

72 degrees C

What is the sequence of the temperatures of a typical PCR reaction?

94 degrees C, 60 degrees C, 72 degrees C

Which of the following best describes a clone in the context of genetic modification procedures?

A culture of genetically identical cells

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 the gene for hGH was inserted into bacteria so obtaining it was not only from human cadaver brains- The bacteria now produces hGH protein that is harvested and purified for a safe and relatively inexpensive source of hGH

Which of the following best describes why a vector is used in genetic modification procedures?

Cells usually won't copy an isolated gene sequence

What is meant by selective toxicity?

Chemotherapeutic agents should act against the pathogen and not the host

Quinolones and fluoroquinolones act against what bacterial target?

DNA gyrase

Which of the following attaches the target gene to a desired location?

DNA ligase

Membrane transport proteins are required for which modes of antibiotic resistance?

Efflux pumps, beta-lactamases, and modification of porins all utilize membrane transport proteins

Why are chemotherapeutic agents that work on the peptidoglycan cell wall of bacteria a good choice of drug?

Humans and other animal hosts lack peptidoglycan cell walls

The typical genetic modification procedure in order:

Isolate bacterial plasmid Select gene of interest + insert into plasmid Plasmid taken up by bacterium Bacteria replicate Cloned gene/ protein product harvested from bacteria

Why is polymyxin only used on the skin?

It can also damage living human cell membranes, but the drug is safely used on the skin where the outer layer of cells are dead

Why would a recombinant DNA molecule be inserted into a host cell?

It can be copied, transcribed, and translated into a desired protein

Why is DNA polymerase from Thermus aquatics ideal for PCR?

It can withstand the high temperatures associated with PCR

Bacteria that are resistant to sulfonamide have enzymes that have a greater affinity for what?

PABA

Which antibiotic is overcome by beta-lactamases?

Penicillin

Why would an efflux pump for penicillin located on a bacterial cell membrane not be effective at providing resistance to the drug?

Penicillin disrupts the cell wall, which is located outside of the cell membrane

Recombinant DNA techniques typically involve generating a clone. Why?

Producing a clone generates many copies of the gene of interest

How might efflux pumps increase antibiotic resistance in bacteria?

Resistant bacteria can have more efflux pumps, and can have less specific efflux pumps

Which of the following mutations would not result in antibiotic resistance?

Silent mutation

What is meant when a bacterium is said to become "resistant" to an antibiotic?

The bacterium is neither killed nor inhibited by the antibiotic

How do the strands separate during PCR?

The high heat of the denaturation step breaks the hydrogen bonds between the two strands

What is 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 is the function of the primers in PCR?

They provide a 3' end for the DNA polymerase

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 undesireable gene, or replace a defective gene with a functioning gene

Why is it difficult to find good chemotherapeutic agers against viruses?

Viruses depend on the host cell's machinery so it is hard to find a viral target that would leave the host cell unaffected

R-plasmids are most likely acquired via

bacterial conjugation.

The process of acquiring antibiotic resistance by means of bacteriophage activity is called

transduction