Final Exam Flashcards
What best describes a symbiotic relationship in which both organisms benefit?
mutualism
Which of the following bacteria do NOT have a cell well?
mycoplasmas
Prokaryotic cells that move in response to nutrient levels are said to display
chemotaxis
Which of the following contains DNA or RNA but not both?
Viruses
An obligate halophile requires high
salt
In a chemical reaction, enzymes ___ the activation energy and ___ the reaction rate.
lower; increase
Which of the following is a direct counting method?
viable plate count
Psychrotrophs would be expected to grow
at refrigeration temperatures
Which of the following is NOT a bacterial shape or arrangement?
bacilli in chains
Which bactereial structure is primarily responsible for preventing bacteria from being destroyed by the hosts immune cells?
capsule
The initial step in the process of many bacterial infections is adhereence of the microbe to mucous membranes. The bacterial component that mediates adhereence is the
pilus
Plasma membranes are composed principally of
protein and phospholipid
Which type of organism gets energy from breaking down organic molecules and uses sugars as a carbon source?
chemoheterotroph
The difference between simple diffusion and facilitated diffusion is that simple ediffusion
does not require a protein
The breakdown of a protein into its building blocks (amino acids) is
catabolic and exergonic
Which of the following can be determined using simple stains?
size, shape and cellular arrangement
Microbes that primarily infect the lungs are likely to be classifed as
obligate aerobes
Certain antibiotics, such as streptomycin, inhibit bacterial protein synthesis by targeting the
70s ribosome
What is the difference between spirilla and spirochetes?
spirilla are rigid with external flagella; spirochetes are flexible with internal flagella
Helicobater pylori is a bacterial pathogen known to cause gastric ulcers and stomach cancer in humans. Which term best describes H. pylori?
mesophilic acidophile
Abiogenesis refers to the
spontaneous generation of organisms from nonliving matter
Lysozyme in tears is an effective mechanism for precenting bacterial conjunctivitis (pink eye), Which bacterial structure does lysozyme degrade?
peptidoglycan
Which of the following statements is FALSE regarding mitochondria?
mitochondria are not found in plant cells
What enables competitive inhibitors to bind to a specific enzyme?
competitive inhibitors have structures that resemble the enzyme’s substrate
Carbonic anhydrase is an enzyme that solubilizes CO2 so that it can be removed from human tissues. Zinc is required for this enzyme to function. Thus, zinc is best described as a(n) ___ that is required to form the functional ___
inorganic cofactor; holoenzyme
How does a noncompetitive inhibitor reduce an enzyme’s activity?
The inhibitor binds to a location other than the active site, changing the shape of the active site.
What is the advantage of the spiral movement of spirochetes?
It allows the cells to move more easily through viscous human tissues and fluids, such as mucus.
Catabolic and anabolic reactions are coupled (connected). Which statement best describes this relationship?
Catabolic reactions provide energy and smaller molecules required for anabolic reactions.
Mycobacterium tuberculosis is grown for 80 hours. During that time, they go through four generations of growth. What is the generation time in minutes?
80 hourts/ 4 generations = 20 hours * 60 minutes… 1200 minutes/generation
What. is the total number of bacteria produced if 10 bacteria undergo binary fission for. 5 generations?
10 x 2^5
What tube below. shos the. expected growth pattern for a facultative anaerobe?
B
Whichtube below shos the expected growth pattern for a microaerophile?
E
In the figure below, which represents a cell wall that possesses endotoxin?
B
In the figure below, which represents a cell wall sensitive to the antibiotic penicillin?
A
Which of the. following would you expect to find in Gram-ppositive cell walls?
Peptidoglycan…teichoic. acid
Which of the following include eukaryotic cells?
Fungi, animals, helminths
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After using an inoculating loop to transfer a culture from one medium to the next, what step should be taken next to avoid contamination?
Heat the inoculating loop with the bunsen burner flame until it becomes red hot.
Immersion oil should be cleaned off an objective with which product
lens paper
The 40x objective of a light microscope is also known as the __ objective
high-dry
You have just rotated the 40x objective into position after viewing the specimen with the 10x objective. What should be your next step?
adjust the fine focus knob
What is the purpose. of heat fixing your slide before staining?
Heat fixation adhere the cells to the slide and coagulates thebacterial proteins, effectively killing the bacteria
What does ubiquitous mean?
Everywhere or in large amounts q
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An inanimate object capable of being contaminated by infectious microbes is known as a(n)
fomite
Small, circular DNA molecules that replicate independently of bacterial chromosomes are called
plasmids
hich scientist is most responsible for finally disproving the. theory of spontaneous
Louis Pasteur
Some bacteria are obligate anaerobes. Which statement best explains this phenomenon?
They lack superoxide dismutase and catalase.W
hich is the acid-fast stain clinically useful?
It identifies the causative agents of leprosy and tuberculosis.
Which of the following steps in viral multiplication is only true of animal viruses?
uncoating
Which receptors of the influenza virus are responsible for binding to the host cell?
hemagglutinin
The region of DNA to which RNA polymerase binds to initiate transciption is called the
promoter
Transcription produces which of the following?
mRNA, rRNA, and tRNA
Corynebacterium. diphtheria is made virulent by incorporated prophage. genes encoding the diphtheria toxin. What term describes this process?
lysogenic conversion
Which of the following is NOT a characteristic of DNA replication?
new strands made in a 3’ -> 5’ direction
According to the operon model, a repressible enzyme will stop being produced when the
end-product is in excess
Deleterious mutations of ___ would result in the lac operon always being turned on.
repressor
RNA molecules. differ from DNA molecules because only RNA
All choices are correct
A gram-negative bacilli infection would be best treated with
aminoglycosides
Which viruses can cause gastroenteritis. with acute diarrhea?
Noroviruses and rotaviruses
Which of the following does NOT apply to shingles?
Occurs before chickenpox
Which of the following is NOT a chacteristic of the genetic dode?
all of the above are true of the genetic code
The analysis of the bases of the nucleic acid of a newly discoveredvirus showed 20% adenine, 40% G, 10% T and 30% cytosine. Thee viral nucleic acid is most likely
single-stranded DNA
Important charactereistics of antimicrobic drugs include all of the following EXEPT
has a low therapeutic index
The cellular basis for bactereial resistance to antimicrobics include
All these choices are correct
The most damaging type of mutation is a ___ mutation which can be caused by ___ mutations.
frameshift; deletion and insertion
Which of the following is FALSA regarding the lagging strand of DNA replication?
It is synthesized by DNA polymerase I instead of DNA polymerase III
Regarding both penicillins and quinolones, which one of the following tis the most accurate?
Both are bactericidal drugs
Which of the following is NOT true of measles?
Negri bodies can be found in the brainstem
Transmissible spongiform encephalopathies are
All the choices are correct.
Which of would be the first step in the biosynthesis of a virus with reverse transcriptase?
a complementary strand of DNA must be synthesized from an RNA template.
Bacteriophage replication differs from animal virus replication because only bacteriophage replication involese
injection of naked nucleic acid into the host cell.
All of the following pertain to virus eenvelopes EXPECT they
are located between the capsid and nucleic acid.
All the following are correct about polio, EXEPT
The Salk vaccine contains an attenuated (weakened) virus.
Which of the following is NOT a means of drug resistance in bacteria?
development of a superinfection
Rubella is
associated with congenital transmission causing miscarriage, deafness, and mental defects.
Which is incorrect about rabies?
all are correct statements.
When a virus enters a lysogenic phase, it means the
virus is integrated into the DNA of the host cell and is latent.
You are studying an unknown virus that does not perform transciption to make viral proteins. Which of the following characteristics must also be TRUE for this unkown virus?
The virus has a positive, sense-stranded RNA genome.
Which of the following is a correct statement about eukaryotic mRNA?
mRNA moves from the nucleus to the cytoplasm following RNA processing.
Which of the following statements is FALSE regarding smallpox as compared to chickenpox?
Chickenpox causes a vesicular rash, whereas smallpox causes a maculopapular rash.
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