Micro tests combined
the event of binary fission are I. the cell doubles in size II. the DNA is replicated III. the cell forms a septum IV. the daughter cells are separated what is the correct order?
I., II., III., IV
grams iodine in the gram staining procedure serves as:
a chemical mordant
what is a virion?
a mature virus
Koch's postulates are criteria used to establish that:
a specific microbe is the cause of a specific disease
which of the following organisms would be most likely to contaminate a jar of pickles
acidophile
what of the following statements is incorrect about helminths
adulthood and mating of parasitic helminths occur in the same intermediate host
how should the agar plates be incubated? Why?
agar plates should be incubated upside down to avoid mixing of colonies that might happen because of condensed water drops on the lid
how is air contamination prevented when an inoculating loop is used to introduce or take a bacterial sample to/from an agar plate?
air contamination is prevented by holding the lid at an angle
agar is a complex polysaccharide that comes form a/an
algae
analysis of a urine sample from a patient suffering from bacterial urinary tract infection detected an ammonium release and shift of the urine pH towards more ___ values
alkaline
which statement is false about bacteria
all bacteria are cocci by their shape
important characteristics of antimicrobial drugs include: 1. low toxicity for human tissue 2. high toxicity against microbial cells 3. stability and solubility in body tissues and fluids 4. all of the above
all of the above
sterilization can be achieved by: 1. flash pasteurization 2. boiling water 3. steam autoclave 4. all of the above
all of the above
the mechanism of action of antimicrobial agents include damaging of: 1. cell wall 2. cell membrane 3. protein synthesis 4. all of the above
all of the above
peptone
alternative carbon source provided to support the growth of organisms that do not catabolize sugars
groups of three bases along the DNA of a gene have the code for one ___
amino acid
the property of organism to integrate catabolic and anabolic pathways to improve cell efficiency is called:
amphibolism
if you observe in a starch agar plate zones not colored by iodine in 24-48 hours around inoculated bacteria, that means that these bacteria:
amylase-positive
which of the following is correct about making a smear?
an adequate smear is one that is thin enough to see small groups of cells or individual cells
the alcohol wipe used on a patient's skin before an injection is an example of
antisepsis
the use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is:
antisepsis
___ is a type of microbes that can be found in extreme conditions such as EX a boiling hot spring or highly acidic environment
archaea
acidic dyes:
are negatively charged
the methanogens require environments that
are with hydrogen gas and CO2
a microorganism grows in the lab on medium containing mineral salts but no organic compounds. The organism is likely to be a(n):
autoproph
what antibiotic is mixed with neomycin and polymyxin to make an antibiotic ointment for superficial skin infections?
bacitracin
list the three recognized by current taxonomy proposed by Carl Woese
bacteria archaea Eukaryotic
what are the two types of prokaryotic cellular organisms?
bacteria and archaea
which term best describes an agent that kill microbes as opposed to temporarily inhibiting their growth and reproduction?
bactericidal
viruses that infect bacteria are specifically called:
bacteriophages
placing organisms at 4 degrees Celsius is ___
bacteriostatic
bacteria living in freshwater stream that are transferred to ocean water would
become dehydrated due to loss of water
what type of antimicrobial agents work by inhibiting the formations of the peptidoglycan layer in the bacterial cell wall?
beta-lactams
what is the name of the process in which larger molecules are broken down into smaller products to release energy?
catabolism
you added hydrogen peroxide to a sample of bacteria and observed rapid bubble formation. these bacteria are:
catalase-positive
what is binary fission
cell growth followed by division to produce two daughter cells
the microorganisms that recycle nutrients by breaking down dead matter and wastes are called:
decomposers
a nutrient medium that has all of its chemical components identified ant their precise concentrations known and reproducible is termed:
defined
phenol red
detects changes in pH based upon the production of acidic or basic productions
which type of medium distinguishes different types of microorganisms based on an observable change in the colonies or in the medium?
differential
the use of a physical or chemical process to destroy vegetative pathogens on inanimate objects is:
disinfection
surfacants work by:
disrupting membrane integrity
the process by which a cell uses ATP to enclose a substance in its membrane, by forming a vacuole and engulfing it:
endocytosis
The blood agar is ___ medium
enriched and differential
which of the following is not associated with every virus?
envelope
each of the following affect cell walls except: 1. penicillin 2. vancomycin 3. erythromycin 4. cephalosporin
erythromycin
which of the following antimicrobial agents is most toxic to humans
ethylene oxide
which of the following is a serilizing agent?
ethylene oxide
according to current taxolog, algae belong to:
eukaryotes
a certain type of archaea live in a lake with pH 3.0 based on their pH preference, they are considered the be alkalinophiles (true/false)
false
a selective medium contains one or more substances that inhibit growth of some microbes to facilitate the growth of other desired microbes (true/false)
false
all animal cells have a cell wall (true/false)
false
all bacterial cells contain double stranded RNA (true/false)
false
all fungi are unicellular (true/false)
false
amylase is an endoenzyme in bacteria (true/false)
false
an obligate anaerobe requires oxygen for growth (true/false)
false
mixed cultures are also referred to as contaminated culture (true/false)
false
the ability of a microscope lens to gather light is referred to as its magnification (true/false)
false
the specimen preparation technique that is best for viewing cell motility is the streak-plate technique (true/false)
false
to induce an aerobic condition in the oxidation-fermentation test tube we would add mineral oil to the top of media (true/false)
false
What is the purpose of flaming the loop before and after use?
flaming the loop before use insures that it is sterile, whereas flaming the loop after use prevents contamination of counter tops and additional cultures
when it is important to count the number of cells, determine cell size and differentiate between dead and live cells, ___ is used
flow cytometer
which of the following statements correctly determines the process when following the scientific method?
formulate question, conduct research, propose hypothesis, test hypothesis
psychrophile is an organism that grows optimally at temperatures ranging:
from 0 to 15 degrees Celsius
Hyphae are associated with
fungi
when humans manipulate the genes of microorganisms, the process id called:
genetic engineering
which of the following statements concerning glycolysis is true
glucose is catabolized into pyruvate. ATP is produced
what is an external structure of prokaryotic cells that helps them to form a biofilm on a surface?
glycocalyx
which of the following prokaryotic cells contain an outer membrane
gram-negative bacteria only
is a microbiology lab student left the safranin out of the gram stain procedure (but all previous steps were completed), what would be the results?
gram-positive cells would be purple and gram-negative cells would be colorless
what is the purpose of heat fixing the smear
heat fixing kills the bacteria
which of the following is an example of pasteurization?
heat is used to kill potential pathogens in apple juice
inoculating loops and needles are made of Nichrome or platinum because these metals:
heat rapidly
once flamed. inoculating loops and needles should be cooled by
holding it and waiting briefly
which of the following describes the transfer of genetic information within the same generation?
horizontal transmission
host cells of viruses may include
humans and animals, plants and fungi and bacteria
physical agents for controlling microbial growth include all of the following except: 1. hydrogen peroxide 2. ultraviolet radiation 3. boiling water 4. pasteurization
hydrogen peroxide
where the electron transport chain occurs in prokaryotic cells?
in the cytoplasmic membrane
in lab, inoculating loops are sterilized using:
incineration
newly inoculated cultures must be ___ at a specific temperature and time to encourage growth
incubated
The five I's of studying microorganisms include all of the following except: identification isolation infection inoculation incubation
infection
the mechanism of action of erythromycin:
inhibition of protein synthesis
the event that occurs in bacteriophage multiplication that does not occur in animal virus replication is:
injection of only the viral nucleic acid into the host cell
the term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is:
inoculation
the correct microbial term for the tiny sample of specimen that is put into a nutrient medium in order to produce a culture is the:
inoculum
which of the following best describes the mechanism of action of strptomycin?
it inhibits protein synthesis by targeting the 30s ribosome
which of the following is not true about anaerobic respiration?
it uses the same final electron acceptor as aerobic respiration
what determines the genotype of a cell?
its DNA
which of the following is a fermentation product useful in the manufacture of yogurts
lactic acid
the phase of the bacterial growth curve in which newly inoculated cells are adjusting to their new environment, metabolizing but not growing at an exponential rate:
lag phase
pathogenic microbes that grow at human body temperature are classified as:
mesophiles
viruses exhibit all the following except
metabolism
which of the following are not considered microorganisms?
microbiome
a measurement of a bacteria is reported as 1 x 10^-6 m, also known as:
micrometers
which of the following characteristics is not observable when simple staining is preformed?
motility
Eosin-methylene blue agar is a commonly used bacteriological medium for growing gram-____ bacteria from complex environments. It contains two dyes, eosin and methylene blue, as well as the sugar ____. The medium is ____
negative, lactose,selective and differential
a naked virus only has a/an
nucleocapsid
what is the main structural feature that eukaryotic cells possess, but prokaryotic cells lack?
nucleus
in general, most DNA viruses multiply in the host cell's ___, while most RNA viruses multiply in the host cell's___
nucleus, cytoplasm
magnification is achieved in a compound microscope through the initial magnification of a specimen by the ___ lens. This image is then projected to the ___ lens that will further magnify the specimen to form a virtual image received by the eye.
objective, ocular
what type of microbes must possess the enzyme superoxide dismutase
obligate aerobes
The DNA fragments that constitute the lagging strand during DNA replication are called:
okazaki fragments
a pure culture contains
only one identified species of microorganism
a microorganism that does not have catalase or superoxide dismutase would find it difficult to live in an environment with:
oxygen
which of the following statements regarding antimicrobial resistance is most accurate?
pathogens can become resistant to multiple antimicrobial agents
an organism that produces catalase is protected from the harmful effects of:
peroxide anion
which type of microscopy transforms the subtle variations in cell density into differences in light intensity, allowing for increased internal detail without staining?
phase-contrast
predominant lipids found in the cytoplasmic membranes of all eukaryotic cells are:
phospholipids
the lipid group that is the major component of cell membranes is the:
phospholipids
an organism that uses light energy to form ATP and can only grow on organic carbon sources is called:
photoheterotroph
an aquatic microbe that can grow only near the surface of water is probably which of the following?
phototroph
each of the following targets bacterial ribosomes, except: 1. polymyxins 2. tetracycline 3. erythromycin
polymyxins
which of the following microorganisms is most resistant to antimicrobial agents?
prions
to retrieve a sample from a culture tube with an inoculating loop, the cap of the tube is:
removed and held with the last two fingers of the loop hand
a microscope's ability to distinguish between two objects that are close together is called a:
resolution
which cellular structures translate messenger RNA (mRNA) molecules into polypeptides?
ribosome
a halophile would grow best in
salt lakes
which of the following represents the use of osmotic pressure as a microbial control method?
salting of meat
a ___ derives its nutrients and energy from the organic matter of dead organisms, whereas a ___ lives in or on another living organism and derives its nutrient and energy from that living organism
saprobe, parasite
carbohydrate source
serves as the primary energy source, used to detect fermentation
Ideally, the bunsen burner flame:
should be blue
if the codon AAA is changed to AAG, it still codes for the aa lysine; this is an example of a:
silent mutation
If pathogen A is more resistant to an erythromycin disc on a Kirby-Bauer plate compared to pathogen B, then pathogen A will have a/n ___ zone of inhibition compared to pathogen B
smaller
the thee physical forms of laboratory media are
solid, semisolid and liquid
the three physical forms of laboratory media are:
solid, semisolid and liquid
what is defined as the removal of all microbes in or on an object?
sterilization
antibiotics such as ___ are highly effective against most gram-negative bacteria
streptomycin and tetracycline
a drug that inhibits folic acid synthesis:
sulfonamide
DNA polymerase III______
synthesizes new DNA only in the 5' to 3' direction
which of the following groups of drugs can become incorporated into the teeth enamel?
tetracycline
the formation of citric acid occurs in
the Krebs cycle
enteric bacteria are facultative anaerobes, meaning they are capable of both aerobic and fermentative metabolism. What results would you expect to see in both sealed and unsealed O-F tubes inoculated with such bacterium?
the aerobic tube would be yellow and the anaerobic tube would be yellow
a microbiologist inoculated Staphylococcus epidermis and Escherichia coli into a culture medium. Following incubation, only the E. coli grows in the culture. What is the most likely explanation?
the culture medium was selective
In the experiments constructed by Pasteur to disprove spontaneous generation, swan-necked flasks were used. Why was this shape used in this experiment?
the glass necks needed to be open to the air, yet constructed so that bacteria would settle in the lower part of the neck.
why must the loop be cool before you touch it to a culture?
the loop must be cool to avoid scalding the microbial cells
which statement regarding prokaryotic chromosomes is incorrect?
there are two copies of the chromosomes so that cells are diploid
what type of microorganism would you find living near hot springs?
thermophiles
which is not a characteristic of plasmids
they are always found in the nucleoid
which of the following statements about algae is false?
they are important in the degradation of dead plants and animals
which of the following is not a characteristic of protozoa?
they are photosynthetic
what type of medium is used to demonstrate oxygen requirements of microbes?
thiogylcollate
which of the following is a function of the cytoplasmic membrane?
to control the passage of substances into and out of the cell
which of the following is not a reason why scientists use stains to view microbes?
to observe the specimen while it is still alive
what term describes the process of copying DNA to RNA
transcription
The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called:
transfer RNA
select the type of microscope that allows for the visualization of intracellular organelles and viruses in thinly sliced specimen preparations
transmission electron microscopy
durham tube
traps gas that is potentially produced during fermentation
In scientific method, a hypothesis must be tested many times before it can be considered a theory (true/false)
true
anabolic reactions can be characterrized as forming larger molecules from smaller molecules (true/false)
true
dry heat is less efficient than moist heat (true/false)
true
enzymes act as a catalyst to lower the activation energy of a chemical reaction (true/false)
true
horizontal gene transfer between bacteria spreading R (resistance) plasmids can result in development of drug resistance in bacterial populations (true/false)
true
lithoautotrophs use inorganic nutrients for carbon and energy sources (true/false)
true
mycology is a study of fungi. (true/False)
true
potential number of ATP molecules produced per molecule of glucose via fermentation process is substantially lower than via aerobic respiration (true/false)
true
the Kirby-Bauer test uses an agar surface seeded with the test bacterium, and a small disc containing a specific concentration of an antibiotic is placed on the surface (true/false)
true
the degree of turbidity in a culture correlates to the amount of cell growth (true/false)
true
the structure of amino acids does not include phosphate group (true/false)
true
which of the following is not used to culture viruses?
typtic soy agar
which of the following causes mutations by creating thymine dimers?
ultraviolet light
which of the following is used for microbial control in fresh fruits and vegetables?
ultraviolet light
the process of dissolving the envelope and capsid to release the viral nucleic acid is:
uncoating
DNA includes the following nitrogenous bases except
uracil
the metabolic processes called fermentation
use an organic molecule as a final electron acceptor
infectious naked strands of RNA that affect plants are called
viroids
among the types of microorganisms, the ____ are non cellular.
viruses
Eukaryotic cells are larger than bacterial or archaeal cells; all cells are larger than macromolecules. Where do viruses fit on this scale?
viruses are smaller than bacterial or archaeal cells, but larger than macromolecules
all of the following are true about viruses except
viruses can exist only in an intracellular state
an enzyme that joins together fragments of DNA is called:
DNA ligase
which activity is an example of biotechnology?
Escherichia coli producing human insulin
viral nucleic acid types include which of the following? 1. double stranded DNA 2. single stranded DNA 3. double stranded RNA 4. single stranded RNA
1. double stranded DNA 2. single stranded DNA 3. double stranded RNA 4. single stranded RNA ALL OF THE ABOVE
which of the following are types of cytopathic effects? 1. inclusions in the nucleus 2. multinucleated giant cells 3. inclusions in the cytoplasm 4. all of the choices are correct
1. inclusions in the nucleus 2. multinucleated giant cells 3. inclusions in the cytoplasm 4. ALL THE CHOICES ARE CORRECT
binary fission occurs every 30 mins, started with 10 cells, how many cells they give in 2 hours
10 x2^4 = 160
characteristics exhibited by all cellular microbes include all of the following except: 1. cytoplasmic membrane 2. nucleus 3. nucleic acid 4. ribosomes
2. nucleus
a loop is preferable more than a needle for inoculating bacteria in all procedures except: 1. inoculating a petri plate 2. inoculating a test tube with broth 3. inoculating a slant 4. inoculating a test tube with semisolid media
4. inoculating a test tube with semisolid media
which of the following is essential for development of discrete, isolated colonies? 1. broth medium 2.differential medium 3. selective medium 4. solid medium
4. solid medium
aseptic technique is important for all the following reasons except: 1. aseptic technique prevents the introduction of unwanted microorganisms into our culture chambers 2. aseptic technique prevents us from transferring microbes to ourselves 3. aseptic technique reduces environmental contamination 4. aseptic technique protects the supporting staff from potential sickness 5. aseptic technique helps to increase the number of cells that are members of the normal microbiota
5. aseptic technique helps to increase the number of cells that are members of the normal microbiota
which of the following is a universal start codon?
AUG
Mannitol salt agar is selective for
Staphylococcus
which scientific name is written correctly?
Staphylococcus aureus (italicized)