More Math
If the magnification of the ocular lens is 15X and the magnification of the objective lens is 40X, what is the total magnification?
600X
Are antibiotics resistant to bacteria or are bacteria resistant to antibiotics?
bacteria are resistant to antibiotics
What is the chemical equation for the reaction produced by catalase enzymes?
H2O2 --> H2O + 1/2 O2
What is the default state of a repressible enzyme?
on (needs to be turned off)/produced unless something prompts it to stop
True or false? Protozoa are not capable of photosynthesis.
true
If the individual dilution factors for a serial dilution are 10-1, 10-1, 10-2, 102, 10-1, what is the total dilution factor?
10-7
What does MRSA stand for, and what settings is it typically spread in?
methicillin-resistant Staphylococcus aureus is typically spread in hospitals and nursing homes
What is the natural substrate that reacts with beta-galactosidase?
lactose
Is the lac operon an example of an inducible or repressible gene?
inducible
True or false? Protists are prokaryotic organisms.
false
If the limit of resolution for a particular objective lens is 320 nm, the numerical aperture of the objective lens is 1.50, and the numerical aperture of the condenser lens is 0.25, what is the wavelength of light being used?
560 nm
If the intermediate zone diameter is 12-14 mm for streptomycin and 13-17 mm for chloramphenicol, and E. coli has a ZOI of 15 mm for streptomycin and 16 mm for tetracycline, which antibiotic should be used to treat an E. coli infection?
streptomycin
If there is coliforms present in a culture that aren't E. coli, what color will the colilert test be in normal lighting and what color will it be under UV light?
yellow in normal lighting, will NOT turn blue fluorescence under UV light
What substrate does amylase break down?
starch
_____ are asexual spores that form at the end of hyphae.
conidia
Calculate the mutant cell density if the number of mutant colonies counted on a plate was 34, the total dilution factor was 100, and the plate volume was 1.25 mL.
27.2 CFUs/mL
What are two things that contribute to increasing antibiotic resistance?
- overuse and misuse of antibiotics
- not finishing the full coarse of antibiotics that are prescribed
What are the two substrates used in the colilert test and what enzymes do they react with?
- DNPG (beta-galactosidase)
- MUG (glucuronidase)
If both starch and glucose are present, will amylase be produced and will a zone of clearing be present?
amylase will not be produced; a zone of clearing will not be present
What is the difference between protophyta and protozoa?
protophyta are "plant like" and protozoa are "animal like"
Calculate the original cell density of a culture if the following were obtained
- plate 1: 33 colonies, 10-8 TDF, 0.1 mL plate volume
- plate 2: 24 colonies, 10-9 TDF, 0.1 mL plate volume
- plate 3: 159 colonies, 10-3 TDF, 0.1 mL plate volume
1.65 x 1010 CFUs/mL
Explain how antibiotic resistance develops in bacteria.
mutant bacteria that are resistant to a particular antibiotic survive when the antibiotic is used to kill other non-resistant bacteria, and then go on to pass the mutant trait on to future generations
MacConkey agar contains which substrate that can be fermented and subsequently produce a reaction with the indicator dye that is present?
lactose
Why are some enzymes inducible/repressible?
to save energy; if the enzymes aren't needed all the time, a lot of energy would be wasted producing the enzymes
when distinguishing fungal and bacterial cells microscopically, fungi have a ______, whereas bacterial cells do not. When distinguishing fungal and bacterial colonies on agar, fungi appear ______, whereas bacteria cells do not.
nucleus/nuclei; fuzzy