Quiz Content Flashcards
Which error(s) has/have been made in the following reference.
Serafini, M., Bugianesi, R., Maiani, G., Valtuena, S., De Santis, S., & Crozier, A. (2003). Plasma Antioxidants From Chocolate. Nature, 424(6952), 1013-1013.
- article title should be in sentence case
- journal name should be italicized
Which of the following is the correct way to reference the following website:
A) Centers for Disease Control and Prevention. (2022). Listeria outbreak linked to ice cream. U.S. Department of Health & Human Services. https://www.cdc.gov/listeria/outbreaks/monocytogenes-06-22/index.html Links to an external site.
B) Centers for Disease Control and Prevention. (2022, July 13). Listeria outbreak linked to ice cream. U.S. Department of Health & Human Services. https://www.cdc.gov/listeria/outbreaks/monocytogenes-06-22/index.html Links to an external site.
C) Centers for Disease Control and Prevention. (2022, July 13). Listeria Outbreak Linked to Ice Cream. https://www.cdc.gov/listeria/outbreaks/monocytogenes-06-22/index.html Links to an external site.
D) Centers for Disease Control and Prevention. (2022, July 13). Listeria outbreak linked to ice cream. U.S. Department of Health & Human Services. https://www.cdc.gov/listeria/outbreaks/monocytogenes-06-22/index.html Links to an external site.
A and D
Which error(s) has/have been made in the following reference.
What is the correct in-text citation for this reference?
Kroupitski, Y., Pinto, R., Brandl, M. T., Belausov, E., & Sela, S. (2009). Interactions of Salmonella enterica with lettuce leaves. Journal of applied microbiology, 106(6), 1876-1885.
journal title should be in title case & italicized
microbial names should be in italics
(Kroupitski et al., 2009)
Which error(s) has/have been made in the following reference.
Book title: Advances in methods for food authenticity testing
Publication date: 2016
Publisher: Woodhead Publishing
Editor: Gerard Downey
Chapter title: advances in infrared spectroscopy for food authenticity testing
Chapter authors: Rodriguez-Saona, L. E., Giusti, M. M., and Shotts, M.
Chapter page numbers: 35 - 70.
Reference
Rodriguez-Saona LE, Giusti MM, and Shotts M. (2016). Advances in Infrared Spectroscopy for Food Authenticity Testing. In M. Shotts (Ed.), Advances in methods for food authenticity testing (pp. 35 - 70). Woodhead Publishing.
incorrect formatting of names
book title should be in italics
incorrect formatting of editor name
book chapter should be in sentence case
Multiple scientists from different labs conduct the same experiment and compare answers.
This is an example of:
Reproducibility
How many decimal places are considered significant when measuring using this device? Units are in mL.
1
What’s wrong with this graph?
- regression equation and R^2 values are missing
- absorbance is the dependent variable and should therefore be on the y-axis
- axis labels are missing units
- axis numbers have too many decimal places for concentration. 1 decimal place to include the 0.5 would be sufficient
Which measurement tool is the most precise and why?
P1000
Lowest %CV
%CV = SD/mean * 100
What is the correct way to present the mean of the following data set?
7, 8, 7, 8, 6, 7
7.2
One decimal place should be kept if all data points do not have any decimal places. This helps increase the accuracy of our final answer even though the individual points only have 1 sig fig. It is an exception to the sig fig rules.
What is the correct way to present the mean and SD of the following data set?
7.10
7.11
7.12
7.11
7.10
7.11
7.10
7.11 ± 0.008
What is 528 mg of NaCl/L as a percent?
0.0528
How many bacterial cells (log CFU/g) are in the following food product, if the results represent the number of colonies that formed after 100 uL from the dilution tubes were spread plated on an agar surface?
6.43
What is the detection limit (log CFU/g)? (spread plated)
3.00
How much liquid volume is plated for spread plating?
0.1 mL
How much liquid volume is plated for pour plating?
1 mL
How much liquid volume is plated for petrifilm?
1 mL
You want to conduct a milk protein analysis using a casein protein standard curve. Your standard curve will have 8 points and 3 technical replicates and you will also prepare 3 technical replicates of 2 diluted milk samples. 200 µL of BCA reagent will be added to each sample and standard.
What is the minimum volume of BCA reagent you should prepare?
6.6 mL
How many data points should be removed from the following data set (ie. outliers)
7.12
7.26
7.11
7.16
7.14
1
The step(s) in an experiment where standard solutions undergo the same dilution step(s) as the sample(s) being analyzed, should not be included in the final dilution factor.
True or False?
True.
The step(s) in an experiment where standard solutions undergo the same dilution step(s) as the sample(s) being analyzed, should be included in the final dilution factor.
True or False?
False.
- 5 g of a food product was mixed with 90 g of solvent and filtered.
- 5 mL of the filtrate was then added to a 100 mL volumetric flask and water was added up to the 100 mL line.
- 2 mL of this dilution was then added to 5 mL of reagent. The solution was mixed and then the absorbance was measured at 340 nm. No standard curve was needed.
What is the total dilution?
What is the total dilution factor?
Include 3 sig figs.
Total dilution = 0.000752
Total dilution factor = 1330
You want to replace sugar in your cookie recipe with a low-calorie natural sweetener (stevia or monk fruit) but first want to know how the natural sweeteners will influence the texture, colour, and flavour of the product.
How many independent variables are there?
How many dependent variables are there?
How many levels of the independent variable are there?
1 independent variable (natural sweeteners) with 2 levels (stevia, monk fruit)
3 dependent variables (flavour, texture, colour)
If you want to know how thermal processing time (1, 2, 3, 4, 5 min) at 121°C impacts the quality (colour, texture, consumer acceptance) of canned green beans, which statistical test would you use?
One-way ANOVA
In order to statistically compare means using t-test and ANOVAs, the data must be normally distributed and groups need to have equal variance.
True or False?
True.
When you have too many variables to perform a t-test but your samples are paired, you should conduct a:
Repeated measure ANOVA
2-tailed t-tests are more statistically powerful than 1-tailed t-tests.
True or False?
False.
1-tailed t-tests are more statistically powerful than 2-tailed t-tests.
True or False?
True.
paired t-tests are more statistically powerful than independent t-tests.
True or False?
True.
independent t-tests are more statistically powerful than paired t-tests
True or False?
False.
You want to know if your back-titration method for analysing calcium in milk produces the same value as what is stated on the milk carton.
Which t-test do you use?
One-sample
You want to know if bread baked with wheat flour vs. potato flour have different textures.
Which t-test do you use?
Independent
Three replicates from the same bottle of orange juice are tested for vitamin C levels using two different methodologies and you want to know if the methods produced different results.
Which t-test do you use?
Paired
Regarding correlations and linear regressions, both should be tested for statistical significance.
True or False?
True.
Regarding correlations and linear regressions, both describe linear relationships.
True or False?
True.
Regarding correlations and linear regressions, both involve selecting values for the independent variable.
True or False?
False.
Linear regression is used for predicting values of the dependent variable.
True or False?
True.
Linear regression is used for predicting values of the independent variable.
True or False?
False.
What is the range of Pearson’s correlation coefficient (r)?
-1.0 to 1.0
A correlation is an association but an association is not necessarily a correlation.
True or False?
True.
An association can be non-linear whereas a correlation describes a linear relationship.
R^2 measures the average distance that data points fall from the regression line while standard error indicates how many data points are described by the regression equation.
True or False?
False.
Standard error measures the average distance that data points fall from the regression line while R^2 indicates how many data points are described by the regression equation.
True or False?
True.
Which post hoc test is most accurate and commonly used in research?
Tukey
Fisher LSD is used in FNH 325 the most though.
Which file type is needed to conduct statistical analyses in R?
CSV
Where should tables and figures be placed in reports?
After the first paragraph in which they are mentioned.
Abstracts may not exceed […] words.
250
Sets the stage for the paper.
Introduction
Explains what you did
Materials and methods
Explains what you found
Results
Explains what your findings mean
Discussion
Summarizes main findings
conclusion
Summarizes whole paper
Abstract
Helps interested readers find your paper
Key words
Introduction
Sets the stage for the paper.
Materials and methods
Explains what you did
Results
Explains what you found
Discussion
Explains what your findings mean
conclusion
Summarizes main findings
Abstract
Summarizes whole paper
Key words
Helps interested readers find your paper
What is the proper way to present the following p-value in your results section?
p=0.0005678
p < 0.001
What is the proper way to present the following p-value in your results section?
p=0.012298
p = 0.012
List 4 things that should be included in the materials and methods.
centrifuge speeds
number and types of replicates
times and temperatures
statistical analysis
List 4 things that should not be included in the materials and methods.
calibration of equipment
preparation of microbial media
preparation of acids and bases
preparation of standard curve concentrations
p-values should be included in your conclusion section.
True or False?
False.
p-values should not be included in your conclusion section.
True or False?
True.
An abbreviation spelled out in an abstract must also be spelled out again the first time it appears in the body of the paper.
True or False?
True.
An abbreviation spelled out in an abstract need not be spelled out again the first time it appears in the body of the paper.
True or False?
False.
If your sentence is more than ____ lines long, it is probably a run on sentence.
3
What wavelength do you use when carrying out a BCA assay?
562 nm
What is the principle behind the Bicinchoninic Acid Method protein assay?
Reduction of Cu2+ to Cu1+ by protein in an alkaline solution and the ions will be trapped by two molecules of BCA to create a purple-colored product
What is the problem when your protein standard curve is constructed using concentrations 0 – 2.0 mg/ml (with absorbance of 0.134 – 0.843) but the absorbance of your sample is 0.953?
You cannot ensure that the relationship between concentration and absorbance is still linear to extrapolate the result
What is the maximum volume you can REVERSE pipette with a P200 pipette?
150 uL
When reverse pipetting, the pipette sucks up more solution than the set volume on the pipette.
True or False?
True.
What colour should your BCA working reagent be?
Green
What is the final dilution in the following scenario? Pipetting 1 mL of 10-3 sample into 9 mL of peptone, vortex the solution, then pipette 1 mL of the diluted sample into another screw cap tube containing 9 mL of peptone.
10^-5
What is the range of colony numbers that is suitable for plate count?
25 - 250
How do you properly sterilize the glass hockey stick (spreader)?
Dip it into ethanol then pass it through the flame
What will be the microbial population in the food sample if you count 76 colonies on the spread plate and the dilution being plated is 10-5?
7.6 x 10^7
A student pipettes 1 mL of sample into a screw cap tube filled with 9 mL of peptone, then directly pipettes 1 mL onto a spread plate, quickly passes the spreader through the flame and spreads the liquid around the plate immediately. Identify the incorrect step(s).
- The volume spread plated was incorrect
- The diluted sample was not mixed thus not homogenous
- The spreader was not properly sterilized
What are the steps in a gram staining procedure? [8]
- Apply crystal violet (5 mins)
- Rinse with a few drops of water
- Apply iodine (2 mins)
- Drain
- Add decolorizer (10s or less; until runoff is clear)
- Drain
- Apply safranin (20 seconds)
- Rinse with water and air-dry
Which pipette will you use to dispense 0.1 mL?
P200
What is the function of phosphoglucose isomerase (PGI)?
It converts D-fructose-6-phosphate (F-6-P) to D-glucose-6-phosphate (G-6-P)
What are we measuring in the enzymatic assay to determine the glucose and fructose concentration?
NADPH
What does the absorbance difference of A2 - A1 relate to?
Glucose content
The enzymatic method requires a standard curve.
True or False?
False.
The phenol sulfuric acid method requires a standard curve.
True or False?
True.
What differs between the equations for determining glucose and fructose?
Pathlength
Final volume
What is the name of the antibiotic added to the potato dextrose agar?
Lab 5: Thermal Resistance of Yeast
Chloramphenicol
What is the principle of the HGMF method?
The hydrophobic grid restricts the growth of microorganisms within the grid squares and each positive square regardless of the number of colonies is counted as a single growth unit.
What type of agar will you be using for the HGMF method?
Potato dextrose agar with trypan blue
When you perform the HGMF method plate count, you find that there are two squares occupied with blue colonies. One of the squares has 2 colonies and another one has 3 colonies. What will be the SCORE in this scenario?
2
What unit will you be reporting your answer in for mold and yeast determination using the HGMF method?
log MPNGU/g
What would happen if you forgot to add trypan blue to the agar for the HGMF assay?
the colonies would be difficult to see
What temperature should your samples ideally be when measuring the viscosity and pH?
room temperature
As the viscosity of the yogurt increases, you should use a smaller/larger numbered spindle in the viscometer?
larger
If you get a viscometer reading >100% you should use a [ Select ] spindle and if your reading is <10% you should use a [ Select ] spindle.
If you get a viscometer reading >100% you should use a smaller-sized (larger number) spindle and if your reading is <10% you should use a larger-sized (smaller number) spindle.
As temperature increases, the pH of solutions decreases.
True or False?
True.
As temperature increases, the pH of solutions increases.
True or False?
False.
As temperature increases, the pH of solutions decreases.
What gram stain results would you expect for Streptococcus thermophilus?
Purple, cocci
Gram postive
What gram stain results would you expect for Lactobacillus bulgaricus?
Purple, rod
Gram positive
Your sample shows L = -100 from the HunterLab colorimeter. What is the color of the sample?
It is not possible because the value is out of range
What is the definition of total solids?
The dry matter that remains after moisture is removed
