Biol 151 lab Exam #1

What are the three types of PPE used in this course?

lab coat, nitrile gloves, & protective eyewear

What is the sample conversion from kilogram to grams?

1 Kilogram = 1000 grams

What is the sample conversion from grams to centigrams?

1 gram = 100 centigrams

What is the sample conversion from centigrams to milligrams?

1 centigram = 10 milligrams

What is the sample from milligrams to micrograms?

1 milligram = 1000 micrograms

What is the placements for the P-20 micropipette? (from top to bottom)

tens, ones, tenths

What is the placements for the P-200 micropipette? (from top to bottom)

hundreds, tens, ones

What is the placements for the P-1000 micropipette? (from top to bottom)

thousands, hundreds, tens

What is the % error formula?

(expected weight - actual weight) / expected weight (x100)

What is the dilution factor formula?

DF = vol. sample / (vol. sample + vol. diluent)

What is the independent variable of an experimental design?

variable(s) being manipulated in an experiment

What is the dependent variable of an experimental design?

response to variable(s) being tested (usually what is measured)

What is the controlled variable of an experimental design?

variables that are unchanged or constant between treatments or samples

What is the formula for total dilution factor (TDF)?

TDF = Df₁ x Df₂ x Df₃

On a graph what axis does the independent variable go on?

on x-axis

On a graph what axis does the dependent variable go on?

on y-axis

What are the elements of a graph?

• Descriptive title

• axis titles

• data

• statistics

• A key/legend if needed

What is the field of view (FOV)?

The circle of light that is observed while looking through the microscope

What is magnification?

using the microscope to make something look bigger than actually is

What is resolution?

The ability to distinguish two separate points as being distinct

What is total magnification?

product of magnification of the object lens and the magnification of the ocular (zoom)

What is the formula for total magnification (TM)?

eyepiece magnification x objective magnification

What is the formula for calculating FOV (μm)?

FOV = field number of ocular ÷ objective magnification (1000)

What is contrast?

Depth differ object from its background

What is the components of microscopic observations?

• detailed drawing of specimen

• name of specimen

• labels (if applicable)

• properly calculated scale bar

• total magnification

• detailed scientific observations of microscopic specimen

What is the max resolution of 10x objective lens?

0.2

What is the max resolution of 40x objective lens?

0.5

What is the max resolution of 100x objective lens?

1.0

What is the max contrast of all objective lens?

0.1

What technique was used to make a yeast cell?

particulate mount technique (used when specimen is to small to handle)

What is a whole mount technique?

technique used for preparing a specimen that is thick enough to be physically handled

What do pipettes get set back to after use?

half of their volume

What is the formula to calculate bar length (μm)?

scale bar (mm) ÷ calculated FOV (μm) multiplied by (circle diameter)

What is the formula for true length (μm)?

object length (mm) ÷ bar length (mm) multiplied by (scale bar μm)

What were the two types of cells observed in Kohler Illumination lab?

yeast & elodea cells

What was the biological stain used in kohler illumination lab?

methylene blue stain

What is step 3 of Kohler illumination?

set iris diaphragm to 0.5

What is step 4 of Kohler illumination?

close the field-limiting aperture all the way until see a tiny polygon

what is step 5 of Kohler illumination?

Adjust the condenser lens until the ring is magenta color

What is step 6 of Kohler illumination?

use the centering knobs to place polygon at the edge of FOV

What is step 7 of Kohler illumination?

open up field limiting aperture until the edges of light touches FOV

What is step 8 (final step) of Kohler illumination?

Adjust iris diaphragm to preference of max contrast or max resolution based on objective lens

What does the scale bar do?

represents the actual size of a specimen so we can compare to real-world measurement

What do eukaryotic cells contain that prokaryotic cells

eukaryotic has a nucleus (instead prokaryotic cells have a nucleoid)

What is step 1 of the aseptic technique?

Heat wire loop with bunsen burner til red hot in hardest part of flame to sterilize (allow time to cool)

What is step 2 of the aseptic technique?

Hold liquid culture tube at an angle with cap removed passing over flame

What is step 3 of the aseptic technique?

dip loop into liquid culture, then flame mouth again

What is step 4 of the aseptic technique?

transfer drop of liquid to agar in petri dish while opening lid as little as possible

What is step 5 of of the aseptic technique?

spread loop wire bacteria all over quadrant surface

What is step 6 of the aseptic technique?

used wire loop must be heated red hot to sterilize remaining bacteria

What is Koch’s first postulate?

organism must be present in all individuals suffering from disease and absent from all healthy individuals

What is Koch’s second postulate?

must be possible to isolate the organism from host and grow it as a pure culture

What is Koch’s third postulate?

If organism from pure culture is re-introduced into a healthy host, the disease symptoms must reappear

What is Koch’s fourth postulate?

Organisms isolated from this second host must be identical to those isolated from the original host

Which Koch postulate was tested in Germ theory part 1?

postulates 1 & 2

Which Koch postulate was tested in Germ theory part 2?

postulate #3

Which Koch postulate was tested in Germ theory part 3

Postulate #4

What was the “healthy host” in the Germ Theory labs?

Sterile TSB

What was the negative control in the Germ Theory labs and what does it tell us?

Escherichia coli (not found in individual suffering from disease or the “healthy host”)

What was the positive control in the Germ Theory labs and what does it tell us?

Lactobacillus sp. (found in individual suffering from disease but NOT healthy host)

What is the individual suffering from disease in the Germ Theory labs?

Yogurt (host + bacteria) should be lactobacillus & TSB

What stain was used in the Germ Theory labs?

Gram’s Safranin stain

What are the components needed to properly label petri dish?

• name (first & last)

• date

• lab section

• medium (what type of agar plate Ex: TSA)

• Inoculate (what transferring Ex: Lacto, E. coli, etc)

• Misc info

What is the purpose of aseptic technique?

To avoid cross contamination and keep a sterile environment

What type of slide was prepped/used in the Germ theory lab?

heat fixed slide

When labeling the quadrants of a agar plate what should the order by from the back?

top left (II), top right (I), bottom left (III), bottom right (IV)

What type of shape does lactobacillus have under a microscope?

rod shaped

What type of shape does staphylococcus have under a microscope?

round shape

What elements are needed for proper labilization of inoculated tube?

• name

• date

• lab section number

• type of media in tube

• what was inoculated

What are non discrete colonies of bacteria?

colonies that are not isolated

What are discrete colonies of bacteria?

colonies that are isolated