In which phase of the bacterial growth curve is the Log (Exponential) Phase
doubling time constant and the cells most susceptible to
3 multiple choice options
the action of Beta-lactam antibiotics?
The remarkable heat resistance of bacterial endospores Calcium dipicolinate
is primarily attributed to the presence of which chemical
3 multiple choice options
complex in the core?
Microorganisms that are a major cause of food spoilage Psychrotrophs
in refrigerators because they can grow at 4°C but have
3 multiple choice options
an optimal growth temperature of 20-30°C are:
What is the fundamental principle behind the "Gram Differences in the thickness and cross-linking of the peptidoglycan layer
Stain," allowing the differentiation of bacteria into two
3 multiple choice options
large groups?
Which sterilization method uses moist heat under Autoclaving
pressure to achieve 121°C for 15 minutes, making it
3 multiple choice options
suitable for surgical instruments but not for heat-sensitive
plastics?
Which mechanism of genetic transfer involves a Transformation
"competent" bacterial cell taking up "naked" DNA from 3 multiple choice options
the surrounding environment?
Genetic elements that can move as a single unit from one Transposons
DNA location to another (e.g., from a chromosome to a 3 multiple choice options
plasmid) are known as:
Which type of mutation results in the creation of a Nonsense mutation
premature stop codon, leading to a truncated and usually
3 multiple choice options
non-functional protein?
In the Polymerase Chain Reaction (PCR), what occurs Specific primers hybridize to complementary sequences on the single strands at
during the "Annealing" step of the cycle? ~55°C.
3 multiple choice options
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, Portage Learning Microbiology Exam 6 - Exam Questions & Verified Answers
Which molecular subtyping method uses pulsed Pulsed-field gel electrophoresis (PFGE)
electrical fields to separate large macrorestriction DNA
3 multiple choice options
fragments and is the PulseNet "gold standard"?
To create recombinant DNA, which enzyme acts as the DNA ligase
molecular "glue" to seal gaps in the sugar-phosphate
3 multiple choice options
backbone?
The fungal cell wall is chemically unique because it Chitin
contains which structural polysaccharide?
3 multiple choice options
Fungi that exist as multicellular thread-like branching Molds; Yeasts
filaments are categorized as ______, while unicellular forms
3 multiple choice options
are ______.
A laboratory test that produces bubbles when 3% Catalase
hydrogen peroxide is added to a bacterial colony
3 multiple choice options
identifies the enzyme:
According to the Baltimore classification, Group III dsRNA
viruses are characterized by a genome of: 3 multiple choice options
Why are "Prions" considered unconventional acellular They consist exclusively of infectious protein and lack nucleic acids.
pathogens?
3 multiple choice options
What is the primary purpose of heating blood agar to To release growth factors X and V and inactivate V-factor destroying enzymes.
80°C to create "Chocolate Agar"? 3 multiple choice options
The functional protein-synthesizing machinery of a 70S Ribosome
bacterial cell is the:
3 multiple choice options
The time required for a bacterial population to double in Generation time
number is known as the:
3 multiple choice options
Which chemical mutagen is a base analog that replaces 5-bromouracil
thymine in DNA, leading to AT to GC transitions? 3 multiple choice options
Which class of antibiotics functions by binding to the 50S Macrolides
ribosomal subunit to inhibit protein synthesis?
3 multiple choice options
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