Lab Practical 1 Flashcards
The ability of a microscope to differentiate two closely spaced objects as being distinct from one another:
resolving power
This is the fourth factor that affects the operation of the microscope…the distance between the objective lens and the slide specimen when the lens is in focus:
working distance
What effect does a reduction of illumination have on resolving power?
decreasing illumination tends to increase the contrast and reduce the resolving power of a lens
Term indicating what is in focus under low power should be nearly in focus under the immersion lens also:
parfocal
What is the magnification of the oil immersion lens?
100x
What kingdom are fungi in?
kingdom fungi
Are fungi domain prokaryote or eukaryote?
Domain: Eukarya
Can fungi photosynthesize?
No. They are nonphotosynthetic
Define dimorphic as it applies to fungi:
some are yeast and some are mold
fungal mass or meshwork of furry growth is called:
mycelium
Individual filaments or strands that form the mycelium of fungi is called:
hyphae
How do fungi reproduce?
spores
fungi sexually reproduce with:
zygospores
fungi asexually reproduce with:
sporangiospores, budding, conidiospores
Diseases caused by Candida:
vulvovaginitis, oral thrush
Rhizopus, Aspergillus, and Penicillium cause:
pulmonary infections
What kingdom are Protozoa in?
Protista
What domain are Protozoa in?
Eukarya
Are Protozoa eukaryotic or prokaryotic cells?
eukaryotic
Do protozoa grow in multicellular form?
no, they are single celled heterotrophs
Plasmodium causes:
malaria
The vector for plasmodium:
anopheles mosquito
Toxoplasma causes:
toxoplasmosis
host for Toxoplasma:
cats (pregnant women are vulnerable–can cause birth defects or miscarriage)
What disease does Trypanosoma cause?
Chagas disease and African Sleeping Sickness
Vector of transmission for Trypanosoma:
tsetse fly
What disease is caused by Trichomonas?
STD
What disease is caused by Leishmania?
leishmaniasis
What is the vector for Leishmania?
sand fly
Giardia causes…
severe gastroenteritis by way of fecal-oral route
Balantidium causes…
colitis (fecal-oral route)
What are two ways to contract toxoplasmosis?
feces of cats and eating undercooked or raw meat
What are two medical problems associated with congenital toxoplasmosis?
hydrocephaly, microcephaly, heart defects, blindness
What are fomites?
nonliving surfaces
hemolysis is the….
destruction of red blood cells
What is a blood agar plate made of?
TSA and 5% sheep’s blood
Gamma hemolysis is:
no hemolysis (growth, but still normal red color)
Alpha hemolysis is:
partial hemolysis (produces green pigment/green halo)
Beta hemolysis is:
complete hemolysis (clear halos)
Routes of transmission:
droplets, vectors, airborne (aerosols, dust spores), direct contact, bloodborne, food and water borne, fecal-oral route
What is a pure culture?
a culture of any microorganism that contains only cells of that microorganism
asepsis means…
without any microorganisms
Term for the transfer of microorganisms from one medium to another:
inoculation
What is the purpose of flaming the openings of the test tubes?
prevents contamination by keeping airborne microbes out of the tube
What are two methods of inoculation completed with an inoculating look?
transferring a loopful of liquid suspension of microorganism to a solid surface medium (petri dish of agar or agar slant) or to another liquid medium.
What does nutrient broth contain?
peptone, beef extract, distilled water
sterile means…
free from bacteria or other living microorganisms
How is growth detected in broth?
cloudiness (turbidity)
Agar deeps are stabbed with…
inoculating needle
How is a slant prepared?
liquid agar is poured in tubes and sterilized in the steam sterilizer, then it is allowed to solidify on a tilted board so that the agar surface is on a slant
What is an agar deep?
Agar media that is allowed to solidify while the tubes are upright so that it form a solid plug of medium
What is the solidifying agent in deeps and slants and petri dishes?
agar
Steps for performing aseptic transfer:
flame loop or needle at an angle slowly until it glows red hot, allow loop to cool so it doesn’t kill microbes, flame the lip of the test tube 2x quickly, flame test tube opening and return cap, transfer microbe to agar, flame loop or needle to sterilize.
What kind of stain uses only one dye?
simple stain
What kind of stain uses multiple dyes?
differential stain
What are some examples of basic dyes?
crystal violet, safranin, methylene blue, carbolfushin, malachite green
The lens that one looks through is called (microscope):
Ocular/eyepiece
Vector for African Sleeping Sickness (Trypanosoma brucei)
Tsetse fly
Transmission of Trypansoma cruzi (Chagas disease):
Feces of reduviid bug
What’s an example of an acidic stain?
Nigrosine and India Ink
What does a good quality smear look like?
Hazy/cloudy
What is the charge on a negative stain and what kind of dye is used?
Negative; acidic stain (nigrosine)
Why is a negative stain useful?
To identify morphology
Do you heat fix a negative stain?
No, you do not heat fix so there is NO distortion of the cell morphology
For smear prep and staining, what kind of dye do you generally use for bacteria?
Basic dye
Does a basic stain have a positive or negative charge?
Positive
Why does a negative stain look the way it does?
Because the dye and cytoplasm are both acidic, the dye does not bind to the cell and only the background is stained.
What’s another name for the Schaeffer-Fulton Procedure?
Endospore stain
By what process do endospores form?
Sporogenesis from the sporangium
Term for the change of a spore from the dormant stage to the metabolically active stage…
Germination
As an endospore forms, it accumulates…
Calcium and dipicolinic acid
Where are endospores formed?
Within the vegetative cell
Endospores contain the genus:
Bacillus and clostridium
Aerobic bacteria that form endospores are found in the genus:
Bacillus
Anaerobic bacteria that form endospores are found in the genus:
Clostridium
What kind of dye is used to stain the endospore?
Malachite green
Endospores are resistant to:
Heat
Is a decolorizer used in an endospore stain?
No
Name the primary and secondary stains for an endospore stain:
Primary: malachite green ; Secondary: safranin
What color do endospores stain? What color do the vegetative cells stain?
ES: green; Veg. Cell: pink
In staining procedures, what distorts cell morphology?
Heat fixing
What are two chemicals responsible for endospore resistance?
Calcium and dipicolinic acid
Is endospore formation a method of cell division?
No
What are cardinal temperatures?
Minimum, optimum, maximum
Anti-septics are used on:
Living tissue
Disinfectant is used on:
Non-living surfaces
Give an example of a common resident flora:
Staphylococcus epidermis
Corneybacterium
Proprionibacterium
Give an example of common transient flora:
Staphylococcus aureus
Coliforms (fecal material)
Clostridia
What are TSA plates made of?
Tryptic soy agar
Describe two body mechanisms used to eliminate transient flora:
Lysozyme from sweat glands and low pH of the skin
T/F: coliforms are an example of transient flora.
True
Who established the importance of hand washing to reduce puerperal sepsis?
Semmelweis
Describe a hazard psychotropics present during refrigeration:
They grow at 0 degrees C which allows them to grow in the fridge
Describe a temperature dependent process in Serratia marcescens:
Pigment production
