Cells that are exposed to hypertonic environments will exhibit _______.
In microbiology, the term growth usually refers to ____.
an increase in the number of microbial cells
A cell that uses an organic carbon source and obtains energy from light would be called a ____.
An aquatic microbe that can grow only at the surface of the water is a _____.
Nitrogen is a growth limiting nutrient for many organisms because _________.
only a few microbes can extract it from the atmosphere, but all organisms require it for amino acid and nucleotide synthesis
At temperatures higher than the maximum growth temperature for an organisms _____.
hydrogen bonds are broken, proteins are denatured, and membranes become too fluid
The term barophile refers to which growth requirement?
A _____ plots the number of organisms in a growing population over time.
During which growth phase are bacteria more susceptible to antimicrobial drugs?
Another term for the logarithmic growth of bacterial cells is ____.
New cells are being produced at the same rate as other cells are dying during the _______ of growth.
When cells are metabolically active but not diving, they are in the ____.
Metabolic activity is at maximum level in the ____ of growth.
A fastidious organism might be grown on which type of media?
Obligate anaerobes may be cultured in the laboratory ______.
in a reducing medium
Joan wants to discover a microbe capable of degrading an environmental contaminant. Which process should she use?
MacConkey agar plates represent ________ medium.
both a differential and a selective
A clinical sample labeled as "sputnum" was collected from ____.
All of the following ingredients might be found in complex media EXCEPT:
Which of the following is found at the 5 end of a DNA strand?
a phosphate group
Which of the following types of plasmids allows a bacterial cell to kill its competitors?
Which of the following is NOT a characteristic of Okazaki fragments?
They are longer in eukaryotic cells.
Which of the following is a characteristic of prokaryotic genomes but not eukaryotic genomes?
T or F: Prokaryotic cells are diploid.
T or F: The structure of DNA explains both its ability to encode genetic information and the way in which it is copied during cell reproduction.
A _____ is a set of prokaryotic genes that are regulated and transcribed as a unit.
RNA polymerase initiates transcription by recognizing specific nucleotide sequences called ____.
Which of the following statements concerning transcription in bacteria is FALSE?
The same RNA polymerase transcribes primer RNA mRNA, tRNA, and rRNA.
Which of the following is involved in translation?
mRNA, rRNA, and tRNA are all involved.
A codon is a particular combination of three nucleotides. Therefore, there are ___ of the nucleotides A, C, G, and T.
64 possible combinations
A _______ is a mutant organisms that has different nutritional requirements from the original wild-type organism.
If the codon AAA is changed to AAG, it still codes for the amino acid lysine; this is an example of a _____.
Which of the following causes mutations by creating thymine dimers?
The Ames Test proves that a chemical is _______.
mutagenic in Salmonella
Which of the following are considered to be frameshift mutations?
Both deletions and insertions
DNA damage caused by ethidium bromide results in _______ mutations.
both insertion and deletion
Frederick Griffith discovered _______.
T or F: Most bacteria have a natural ability to take up DNA from their environment.
In conjugation, F+ cells ________.
contain an f plasmid
The horizontal transfer process known as transduction_____.
involved a virus
Another term for the palindromic sequence found at the ends of transposons is _______.
Transfer of DNA between cells by viruses is called _______.
Natural antiseptics such as pine or clove oil are examples of antimicrobial compounds called _______.
Which of the following statements about aldehydes is FALSE?
They are used only to preserve dead tissues.
A scientist develops a new medication that is a protein compound and that must be administered by injection. Which of the following would be the most effective and safest means of preparing a sterile solution of the new medication?
Which of the following would be used to sterilize a mattress?
Which of the following antimicrobial agents is the most toxic to humans?
Betadine is an example of which of the following groups of antimicrobial agents?
Which of the following was used in the past to prevent the transmission of gonorrhea from an infected mother to her newborn?
Which of the following is used to sterilize items that should not, or cannot, be exposed to heat or what?
The chemical agents known as "quats" are used for _______.
The compound ethylene oxide is used in ________.
T or F: Slow freezing is more damaging to microbial cells than quick freezing.
The process of incineration is used for _____.
The process of filtration is a ________.
Which of the following is used for microbial control in fresh fruits and vegetables?
Gamma irradiation is a process for ______.
The endospores of which of the following microbes are used to measure the effectiveness of autoclave sterilization?
Which of the following is the most appropriate pairing of microbe and biosafety level?
Methicili-resistant staphylococcus aureus (MRSA), BSL-2
T or F: Some viruses are inactivated by the same chemical or physical agents that damage cytoplasmic membranes.
Which of the following statements concerning microbial death is FALSE?
It is not an effective means of evaluating the efficacy of antimicrobial agents.
Aseptic means ______.
free of pathogens
A large percentage of antibiotics and semisynthetic drugs are produced by members of the genus ________.
Which scientist coined the term antibiotic?
Which of the following drugs specifically targets cell walls that contain arbinogalactan-mycolic acid?
Which of the following antibiotics disrupts cytoplasmic membrane function?
were the first widely used antimetabolic antimicrobial and indirectly inhibit nucleic acid synthesis
Which of the following pathways is specifically inhibited by sulfonamides?
The conversion of PABA to Dihydrofolic acid.
Antimicrobials that block protein synthesis by binding to mRNA are _________.
antisense nucleic acids
Trimethoprim is an example of antimicrobials which ___________.
inhibit metabolic pathways
The antimicrobial polymyxin ____________.
disrupts cytoplasmic membranes
Nucleotide or nucleoside ________ are antimicrobial agents that mimic the chemical structure of DNA building blocks.
The antimicrobials called quinolones act by ________.
inhibiting nucleic acid synthesis
Methicillin is an example of the B-lactam class of drugs which _____________.
inhibit cell wall synthesis
Most broad-spectrum antibiotics act by ________.
inhibiting protein synthesis
DIsruption of the normal microbiota can result in infections caused by which of the following microbes?
Candida albicans, myobacterium, and clostridium difficle
Which of the following can result when antibiotic therapy disrupts the normal microbiota?
Both pseudomembranous colitis and thrush
Which of the following is NOT a criterion by which all antimicrobial agents can be evaluated?
Their activity against cell walls
T or F: The outer membrane of Gram-negative bacteria enables many antimicrobial drugs to enter the cell more easily.
Which of the following statements concerning development of antibiotic resistance is FALSE?
Resistant cells grow more efficiently and quickly than susceptible cells.
The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid, a B-lactamase inhibitor, is known as ______.
B- Lactamase production is an example of which of the following types of resistance?
Inactivation of the drug
It is inappropriate to prescribe antibacterial agents to treat colds or flus because __________.
these deseases are caused by viruses.
Who discovered the first widely available antibiotic?