Lab2: 1-16 except 14 Flashcards
factors that affects resolution, shorter the wavelength of light used, ___________.-white light used in compound microscope limits resolution of structures smaller then 0.2mm
higher resolution
higher magnification inverse relationship to _________.
lower resolution
the objective lens magnifies the specimen to produce ____1_____ that is projected to ocular lens to produce the _____2_____.
1.real image2.virtual image
list 4 points regarding proper use and storage of microscopes. “just remember”
- use both hands when you carry a microscope to your table.2.plug in the lamp cord into electrical outlet, then turn on the main switch of microscope3. before storing microscope back, replace the low objective lens into working position4. always check before change objective lens to avoid slide breakage.
identify at least 4 differences between prokaryotes and eukaryotes.
prokarytoes:-non membranous-one circular chromosome-divided by binary fission-made of peptidoglycanEukaryotes:-separated from cytoplasm-both membranous & non-membranous-no peptidoglycan-divided by mitosis
what is the biochemical basis of cheek cell staining process, are the cheek cells prokaryotes or eukaryotes?
methylene blue is used to stain animal/human cells to make nuclei more visible under a microscope.-the cheek cell is a eukaryote, because eukaryotic cell contain a nucleus.
Staining:define primary stain
mainly stain all cells
Staining:define mordant
holds the dye down
Staining:define decolorizing
wash of primary stain
Staining:counterstain
color to cells that dont retain the primary stain
describe the principle of gram’s staining process, include the role of each chemical reagent used in the staining process.
To distinquish between two cell wall gram positive and negative.
advantages of the gram’s staining process
advantage:-it’s a relatively rapid and an extremely useful tool-the staining provides suggestive includes during the identification process-it provide valuable information so as to initiate course of antimicrobial treatment
disadvantages of the gram’s staining process
disadvantage:-often, disease causing bacteria, does not have distinct stain characteristic -the stain is not specific enough to diagnose the cause of most infection-some bacterial cells stain poorly or not at all
list 3 precaution for the gram’s stain
1.fixing2.staining3.timing
identify the 2 bacteria’s which characteristically produce spores. name the bacteria you did for that experiment.
1.spore has a thick wall2.is a metabolically inactive structureBacillus anthrasis or Clostridium tetanus
what is 5 features of spores and list spore position inside vegetative cells
- spore begin to isolate DNA replicate2. plasma membrane surround DNA3. spore septum surrounds isolated portion forming forespore4.peptidoglycan layer forms between membrane5.spore coat forms then endospore freed from cell
what are functions of spore?
are reproductive cells that must fuse in pairs in order to give rise to a new individual.
what are differentiate between spore and vegetative cells?
- endospores is form from vegetative cell2.vegetative cell response to environment signals
what is sporulation and germination?
1.sporulation- process of spore formation in a sequential event2.germination - bacterial spore transform into a vegetative cell upon return of favorable conditions by the metabolic process
name 2 bacteria’s which are acid fast positive and the associated disease they cause in humans.
Mycobacterium nocardia>Mycobacterium tuberculosis - causes chronic diseasesMycobacterium leprae - hansen’s diseases
describe the composition of the cell wall that is responsible for the acid fast properties of the cell.
Acid Fast Bacteria are Gram positve, peptidoglycan contain large amout of lipids (mycolic acid).
What is sterile transfer technique?
they incorporate procedures that minimizes chance of other organisms being accidentally introduced.
list 4 factors with regard to importance of the sterile transfer techniques.
- free from containing you or others2. prevent culture from contaminating you or others3.to isolate pure culture of microbes not considered4.prevents observing features of microbes
name 2 methods for pure culture isolation.
1.spreading plating on solid agar medium with a glass spreader.2.streaking plating with a loop
list 3 common errors in colony isolation by the streak process
1.label all media, tubes and cultures2.use a loop which is sufficiently cooled3. avoid aerosols4. disinfects work place
why pour plate technique needs to be done at a faster pace compared to the streak plate method
pour plate needs to be cooled enough before it solidify while streak plate doesn’t
what is peritrichous arrangement of flagella?
peritrichous - Multiple flagella may be randomly distributed over the entire bacterial cell
what is amphitrichous arrangement of flagella?
amphitrichous - A single flagellum (or multiple flagella; see below) can extend from both ends of the cell
what are spirochete?
are flexible, is a member of the phylum Spirochaetes, which contains distinctive diderm bacteria, most of which have long, helically coiled cells
name the disease that caused by the spirochete Borrelia burgdorferri
predominant causative agent of Lyme disease