LEC EXAM #3 worksheet Flashcards
Which of the following regarding the Ames test is true?
It is used to identify mutants with restored biosynthetic activity.
When the ribosome reaches a nonsense codon, which of the following occurs?
The polypeptide is released
The F plasmid is involved in which of the following processes?
Conjugation
The formation of pyrimidine dimers results from which of the following?
Exposure to ultraviolet radiation
Which of the following is an example of a frameshift mutation?
Deletion of one nucleotide
Which of the following refers to the mechanism of horizontal gene transfer naturally responsible for the spread of antibiotic resistance genes within a bacterial population?
Conjugation
An operon of genes encoding enzymes in a biosynthetic pathway is likely to be which of the following?
Constitutive
Which of the following conditions leads to maximal expression of the lac operon?
Lactose present, glucose absent
All of the following are processes used to introduce DNA molecules into bacterial cells except:
Transcription
The enzyme that uses RNA as a template to produce a DNA copy is called:
Reverse transcriptase
Which technique is used to separate protein fragments based on size?
Polyacrylamide gel electrophoresis
Which technique uses restriction enzyme digestion followed by agarose gel electrophoresis to generate a banding pattern for comparison to another sample processed in the same way?
RFLP
The insulin produced by recombinant DNA technology is:
Identical to human insulin produced in the pancreas.
Which of the following types of medical items requires sterilization?
Needles
Which of the following is suitable for use on tissues for microbial control to prevent infection?
Antiseptic
Which of the following best describes a microbial control protocol that inhibits the growth of molds and yeast?
Fungistatic
The decimal reduction time refers to the amount of time it takes to which of the following?
Reduce a microbial population by 90%
Which of the following terms is used to describe the time required to kill all of the microbes within a sample at a given temperature?
Thermal death time
Which of the following microbial control methods does not actually kill microbes or inhibit their growth but instead removes them physically from samples?
Filtration
Which of the following peroxygens is widely used as a household disinfectant, is inexpensive, and breaks down into water and oxygen gas?
Hydrogen peroxide
Which type of test is used to determine whether disinfectant solutions actively used in a clinical setting are being used correctly?
In-use test
Which of the following combinations would most likely contribute to the development of a superinfection?
Short-term use of narrow-spectrum antimicrobials
Which of the following routes of administration would be appropriate and convenient for home administration of an antimicrobial to treat a systemic infection?
Oral
Which clinical situation would be appropriate for treatment with a narrow-spectrum antimicrobial drug?
Treatment of strep throat caused by culture identified Streptococcus pyogenes
Which of the following terms refers to the ability of an antimicrobial drug to harm the target microbe without harming the host?
Selective toxicity
Which of the following is not a type of β-lactam antimicrobial?
Glycopeptides
Which of the following does not bind to the 50S ribosomal subunit?
Tetracyclines
Which of the following antimicrobials inhibits the activity of DNA gyrase?
Nalidixic acid
Which of the following is not an appropriate target for antifungal drugs?
Cholesterol
Which of the following drug classes specifically inhibits neuronal transmission in helminths?
Avermectins
Which of the following is a nucleoside analog commonly used as a reverse transcriptase inhibitor in the treatment of HIV?
Adenine-arabinoside
