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141 terms

Micro Exam 3

STUDY
PLAY
Among the microorganisms, various genomes can include
All of the choices are correct (chromosomes, plasmids, mitochondrial DNA, chloroplast DNA)
The duplication of a cell's DNA is called
replication
RNA molecules differ from DNA molecules because only RNA
All of the choices are correct (has ribose, has, uracil, is typically one strand of nucleotides, does not have thymine)
If a codon for alanine is GCA, then the anticodon is
CGU
A mutation that changes a normal codon to a stop codon is called a
nonsense mutation
If the DNA sequence is ATTCCGGA, the mRNA transcript would
UAAGGCCU
The use of an organism's biochemical processes to create a product is
A. genetic engineering
biotechnology
The various techniques by which scientists manipulate DNA in the lab is called
genetic engineering
The deliberate removal of genetic material from one organism and combining it with the genetic material of another organism is a specific technique called
recombinant DNA
Labeled, known, short stretches of DNA used to detect a specific sequence of nucleotides in a mixture are
gene probes
A technique that separates a readable pattern of DNA fragments is
gel electrophoresis
Analysis of DNA fragments in gel electrophoresis involves
All of the choices are correct (larger fragments move slowly and remain closer to the wells, DNA has an overall negative charge and moves to the positive pole, DNA fragments are stained to see them, an electric current through the gel causes DNA fragments to migrate)
Gene probes can be labeled for detection with
All of the choices are correct (enzymes, fluorescent dyes, radioisotopes)
Amplification of DNA is accomplished by
polymerase chain reaction
The Western Blot technique detects
proteins
The primers in PCR are
synthetic DNA oligonucleotides
When patient tissues are transfected with viruses carrying a needed, normal human gene, the technique is called
gene therapy
Both DNA sequencing and polymerase chain reactions require special __________ to initiate synthesis of a new DNA molecule.
primers
When DNA is heated to just below boiling (90oC - 95oC),
the two DNA strands separate completely
All species of Staphylococcus
lack spores
The toxin of Staphylococcus aureus strains that causes blisters and desquamation of skin in scalded skin syndrome is
exfoliative toxin
A common food intoxication is caused by enterotoxin-producing strains of
Staphylococcus aureus
This pathogen is the most common cause of neonatal pneumonia, sepsis, and meningitis in the United States:
Streptococcus agalactiae
This organism is associated with commonly causing urinary tract infections in sexually active young adult and adolescent females:
Staphylococcus saprophyticus
The most common site where carriers of Staphylococcus aureus carry this pathogen is
A. all over the skin.
The most common site where carriers of Staphylococcus aureus carry this pathogen is
anterior nares (nostrils)
Infections caused by Staphylococcus aureus include all the following except
sore throat
Staphylococci can be differentiated from streptococci by the
catalase test
Streptococcus pneumoniae is
a gram positive diplococcus with a capsule
Neisseria gonorrhoeae is
All of the choices are correct (the cause of ophthalmia neonatorum, the cause of gonorrhea, called the gonococcus, virulent due to pili, and a protease that inactivates IgA)
All of the following pertain to Neisseria meningitidis except
it is a common cause of bacterial pneumonia
The instillation of antibiotics in newborn's eyes will prevent ophthalmia neonatorum in newborns. This disease is caused by
Neisseria gonorrhoeae
The majority of otitis media in children is mainly due to infection with
Streptococcus pneumoniae
Which chemical, produced by S. aureus is also known as "spreading factor"?
hyaluronidase
Which chemical, produced by S. aureus, digests blood clots?
staphylokinase
All of the following are correct about Staphylococcus aureus except
the body's most powerful defense against it lies in the T-cell response
The Five I's of studying microorganisms include all of the following except
infection
All of the following are examples of different types of microbiological media except
petri dish
The term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is
inoculation
Which of the following is essential for development of discrete, isolated colonies?
solid medium
Which method often results in colonies developing down throughout the agar and some colonies on the surface?
pour plate
A common medium used for growing fastidious bacteria is
blood agar
A nutrient medium that has all of its chemical components identified and their precise concentrations known and reproducible, would be termed
synthetic
Which type of medium is able to distinguish different species or types of microorganisms based on an observable change in the colonies or in the medium?
differential
For which bacterial genus is mannitol salt agar selective?
Staphylococcus
The specimen preparation that is best for viewing cell motility is
hanging drop
The primary purpose of staining cells on a microscope slide is to
add contrast in order to see them better
The Gram stain, acid-fast stain and endospore stain have the following in common:
are differential stains
A microbiologist makes a fixed smear of bacterial cells and stains them with Loeffler's methylene blue. All the cells appear blue under the oil lens. This is an example of
simple staining
Bacteria that require special growth factors and complex organic substances are called
fastidious
A media is designed that allows only Staphylococci to grow. In addition, S. aureus colonies have a yellow halo around them and other staphylococci appear white. This type of media is
both selective and differential
All of the following are examples of basic dyes except
crystal violet
Which type of media can be used to determine if a bacteria is motile?
SIM
Which of the following media is useful for cultivating fungi?
Sabouraud's agar
Which of the following puts the Five "I"s in their correct order?
inoculation, incubation, isolation, inspection, identification
Why is oil of immersion often used when viewing specimens under the microscope?
to increase the resolution
All bacterial cells have
a chromosome
The outcome of the Gram stain is based on differences in the cell's
cell wall
Which structure protects bacteria from being phagocytized?
capsule
If bacteria living in salty seawater were displaced to a freshwater environment, the cell structure that would prevent the cells from rupturing is
cell wall
Peptidoglycan is a unique macromolecule found in bacterial
cell walls
A procaryotic cell wall that has primarily peptidoglycan with small amounts of teichoic acid and lipoteichoic acid is
gram positive
A bacterial genus that has waxy mycolic acid in the cell walls is
Mycobacterium
All of the following pertain to endotoxins except they
are found in acid fast bacterial cell walls
The difference in cell wall structure of Mycobacterium and Nocardia compared to the typical gram positive bacterial cell wall structure is
predominance of unique, waxy, lipids
Lipopolysaccharide is an important cell wall component of
gram negative bacteria
The function of bacterial endospores is
protection of genetic material during harsh conditions
Chemical analysis of a bacterial cell structure detects calcium dipicolinic acid. What is the identity of this structure?
endospore
Bacterial endospores are not produced by
Staphylococcus
What is the correct sequence for a Gram stain?
crystal violet, Gram's iodine, alcohol, safranin
Lysozyme, an enzyme found in tears, provides a natural defense against bacteria by
hydrolyzing peptidoglycan in cell walls
In the Gram stain, the mordant is
iodine
Which cell structure is an important agent in modern genetic engineering techniques?
plasmids
All of the chemical reactions of the cell are called
metabolism
Enzymes are
proteins that function as catalysts
Formation of peptide bonds between amino acids to build a polypeptide would be called
anabolism
When enzyme action stops due to a buildup of end product this control is called
negative feedback
Mixed acid fermentation
produces acids plus CO2 and H2 gases
The process of alcoholic fermentation produces
alcohol and carbon dioxide
Microorganisms require small quantities of this nutrient for enzyme function and maintenance of protein structure:
water
An organic nutrient that cannot be synthesized by the organism and must be provided is called a/an
growth factor
The term phototroph refers to an organism that
uses CO2 for its carbon source
The term autotroph refers to an organism that
uses CO2 for its carbon source
The term chemotroph refers to an organism that
gets energy by oxidizing chemical compounds
Diffusion of water through a semipermeable membrane is called
diffusion
The movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and use energy is called
osmosis
Which of the following microorganisms would find hypotonic conditions most detrimental?
protozoa
Which of the following require the cell to use ATP?
endocytosis
Cultures of a bacterial species were incubated on the shelf of a refrigerator, out on a lab benchtop, on the shelf of a 37 C incubator and on the shelf of a 50 C incubator. After incubation, there was no growth at 37 C and 50 C, slight growth out on the benchtop, and abundant growth at refrigeration. What term could be used for this species?
psychrophile
Cultures of a bacterial species were incubated out on the incubator shelf, in an anaerobic jar and in a candle jar. After incubation there was moderate growth of cultures in the candle and anaerobic jars, but heavy growth of the culture on the incubator shelf. This species is a/an
facultative anaerobe
A microorganism that does not have catalase or superoxide dismutase would find it difficult to live in an environment with
oxygen
The majority of organisms live or grow in habitats between
pH 6 and 8
Barophiles are microorganisms able to tolerate
high atmospheric pressure
Which of the following methods of enumerating cells is the only one to detect live cells?
viable plate count
You inoculate a culture into a test tube containing broth and take it out of the incubator the next day. You see the culture is growing equally throughout the broth. You conclude the culture must be
facultative anaerobe
You inoculate a culture into a test tube containing broth and take it out of the incubator the next day. You see the culture is growing at the bottom of the tube. You conclude the culture must be
anaerobic
Facultative anaerobes usually possess
both catalase and superoxide dismutase
Filamentous fungi are called
molds
All of the following pertain to monkeypox except
the virus has shown a trend in becoming less virulent, with fewer outbreaks in humans
Herpes simplex-2 (HSV-2) causes
All of the choices are correct (genital lesions; intensely sensitive vesicles on or near the genitals; symptoms that include urethritis, cervicitis, and itching; infection in neonates that have contact with lesions in the birth canal)
An occasional serious complication of herpes simplex-1 is
encephalitis
Which of the following antivirals is not used for treatment of HSV-1 and HSV-2?
interferon
Chickenpox
All of the choices are correct (is transmitted by inhalation of respiratory secretions, is transmitted by skin lesion contact or airborne spread of lesion material, has an incubation of 10 to 20 days, has fever, and vesicular rash that occurs in successive crops)
Herpes whitlow is a deep set herpes simplex virus infection of the
finger
If a person who has never been infected with the varicella-zoster virus comes in contact with a person who has shingles, they will come down with
chickenpox
Epstein-Barr virus has the following characteristics except
it infects the respiratory epithelium
Symptoms of infectious mononucleosis include
sore throat, fever, cervical lymphadenopathy, and splenomegaly.
The patients at greatest risk for severe cytomegalovirus infection include all the following except
individuals with hypertension
Cytomegalovirus
All of the choices are correct (is among the most common of human infections; is transmitted by saliva, respiratory mucus, milk, urine, semen, and cervical secretions; can be sexually transmitted; is commonly carried in the latent state)
Human herpesvirus 6 (HHV-6) has the following characteristics except
it causes Kaposi's sarcoma
Inflammation of the liver with necrosis of the hepatocytes and swelling due to a mononuclear response is a disease called
hepatitis
Hepatitis B virus
All of the choices are correct (is principally transmitted by blood; transmission risks include shared needles, anal intercourse, and heterosexual intercourse; is transmitted to the newborn from chronic carrier mothers; has many chronic carriers)
Hepatitis B infection
increases risk for hepatocellular cancer
Adenoviruses are
All of the choices are correct (nonenveloped, double-stranded, DNA viruses; transmitted by respiratory and ocular secretions; causes of conjunctivitis, common cold, and an acute hemorrhagic cystitis in children; causes of outbreaks among military recruits)
When bilirubin accumulates in the blood and tissues, it causes
jaundice
Viruses have all the following except
metabolism
The core of every virus particle always contains
either DNA or RNA
Which of the following represents a virus family name?
Herpesviridae
The correct sequence of events in viral multiplication is
adsorption, penetration, replication, maturation, assembly, release
In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's _____.
nucleus, cytoplasm
The virus-induced, specific damage to the host cell that can be seen in a light microscope is called
cytopathic effects
Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called
plaques
Which of the following is a type of cytopathic effect?
All of the choices are correct (inclusions in the nucleus; multinucleated giant cells; inclusions in the cytoplasm; cells round up)
Viruses that consist of only a nucleocapsid are considered
naked viruses
DNA polymerases used in PCR
include Taq polymerases and Vent polymerase
Which PCR step causes the denaturation of double-stranded DNA?
heat target DNA to 94 C
Which PCR step synthesizes complimentary DNA strands?
add DNA polymerase and nucleotides at 72⁰ C
Which step involves transformation?
cloning host receives plasmid
Which step can occur even more rapidly by PCR?
gene is amplified by multiplication of cloning host
This is often used in forensic science to distinguish one sequence of DNA from another by comparing the sequence of the strands at specific loci:
DNA fingerprinting
The Southern Blot technique detects
DNA
This molecule is synthesized as a copy of a gene on the DNA template strand:
messenger RNA
Influenza vaccines include all the following except
provides lifelong immunity
Influenza infection can be treated with
All of the choices are correct (amantadine; rimantadine; zanamivir; oseltamivir)
Parainfluenza virus
causes croup, bronchitis, and bronchopneumonia
Rubella is
associated with congenital transmission causing miscarriage, deafness, and cardiac and mental defects
All arboviruses involve
arthropod vectors
Encephalitis caused by arboviruses involve
All of the choices are correct (fever, headache, and rash; coma, convulsions, paralysis in severe cases; myalgia and orbital pain; muscle aches and joint stiffness)
Documented transmission of HIV involves
unprotected sexual intercourse and contact with blood/blood products
The worldwide, primary viral cause of morbidity and mortality from diarrhea is
Rotavirus
Spongiform encephalopathies are
All of the choices are correct (associated with abnormal, transmissible, protein in the brain; chronic, fatal infections of the nervous system; caused by prions; Creutzfeld-Jacob disease, kuru, and Gertsmann-Strussler-Scheinker syndrome)
The main route for transmission of HIV in most parts of the world is through
heterosexual sex