23L Final
According to the Lab Safety Sheet provided for this week, when working with E. coli cells you must wear: (check all that apply) - Standard lab attire -Lab coat - Safety goggles -Full-face air purifying respirator -Gloves
- Standard lab attire -Lab coat - Safety goggles -Gloves
mean
- measures the central tendency of a variable is mean. -"arithmetic average." - The mean of a sample is calculated as the sum of all measurements in the sample divided by the sample size (n).
During the wet lab portion of the DNA Isolation lab you must wear: (check all that apply) - safety goggles - gloves - standard lab attire - lab coat - respirator
- safety goggles - gloves - standard lab attire - lab coat
What type of blank should be used for the b-galactosidase enzyme activity assay?
"b-gal blank" made by your group
By the end of the third round of the handshaking activity in the Epidemiology Lab, eight people are infected (of the twenty four people in your section). What would be the infection rate at the end of the round 4, assuming no one was infected more than once?
(16/24) x 100%
Given the Series A: 1,2,3,4,5,5,5,5,6,7,8,9.Series A contains a symmetrical unimodal distribution. Which one of the following statement is true about Series A's distribution? -The mean and mode are the same value, but not the median. -The median and mean are the same value, but not the mode. -The mode and median are the same value, but not the mean. -The mean, median and mode are the same value. -The mean, median, and mode are not the same value.
The mean, median and mode are the same value.
Mode
The mode is defined as the measurement of relatively great concentrations in a set of data. - most frequently recurring bimodal= 2 modes
dna gels use which type of gel
agrose, a polysaccharide extracted from seaweed
what does the biochemical assay do for us in the bgal lab?
allows us to determine if: 1. if ecoli synthesizes the enzyme in the absence of lactose 2. the substrate upon which bgal acts if the induction of bgal synthesis in ecoli is time dependent.
You should not participate as a test subject in this lab if you have which of the following conditions: Knee pain A cold or flu Any of these Dizzy spells Arthritis
any of these
why are mitochondrial DNA types (sequences) termed haplotypes .
because the mitochondrial genome is haploid—having only a contribution from the mother
A life science student uses a compound microscope to look at a slide of human tissue. He is not sure what part of the body the tissue is from, but makes an educated guess based on the cells he sees on the slide. There are hundreds of round disks with no nucleus, as well as a couple of purple-colored spherical cells. The student would most likely guess that the tissue is of: Bone Skin Lung Blood Muscle
blood
Which of the following statements about pipetting is FALSE? -When aspirating sample, you should depress the pushbutton to the first positive stop only. -The second stop on the pipetter should never be used under any circumstances. -When expelling sample, you usually depress the pushbutton to the second stop. -It is important that you always hold the pipetter vertically if the tip contains liquid. -You should never handle liquid with a pipetter that has not been fitted with a tip.
The second stop on the pipetter should never be used under any circumstances.
standard deviation
The standard deviation is a measure of variation around the mean. Any measurement that is not equal to the mean is deviated from the mean. T
In a biochemical assay, the transcription of b-galactosidase is monitored in bacterial cells. A substrate that functions like ONPG, however produces a purple color when cleaved, is added to the reaction mixture. Under a constant pH of 7, if b-galactosidase is transcribed in these cells:
The substrate will be cleaved as the mixture produces a purple color.
In the B-galactosidase lab, test tubes A and B were treated with ONPG. After 15 minutes of incubation, test tube A turned a yellow color while test tube B remained a clear color. Test tube __________ contained __________ which reacted with ONPG to produce __________ and __________.
A, b-galactosidase, galactose, o-nitrophenol
Label Pipettor
A- push button B- Volume adjustment ring C- shaft D- ejector E- Disposable tip
All of these statements about electron and compound microscopes are true EXCEPT: An electron microscope has a higher magnification. An electron microscope cannot be used to look at living cells. An electron microscope uses beams of electrons to visualize an image. An electron microscope is more appropriate for analyzing living prokaryotic cells.
An electron microscope is more appropriate for analyzing living prokaryotic cells.
You should not participate as a test subject in this lab if you have which of the following conditions Knee pain Dizzy spells Arthritis A cold or flu Any of these
Any of these
Which of the following is true about the Sanger method? The dideoxynucleotides used in the reaction have a hydroxyl group at the 3' position. The primer used in the reaction has a radioactive or fluorescent label on its 3' end for visualization. The fragments in the four reaction tubes are separated on agarose gel. Each of the four reaction tubes contain only one of the four ddNTPs at a ratio of about 1 ddNTP/50 dNTP. DNA sequencing is rarely done using automated systems.
Each of the four reaction tubes contain only one of the four ddNTPs at a ratio of about 1 ddNTP/50 dNTP.
What are the functions of SDS in gel electrophoresis for estimating protein sizes? (check all that apply) Intercalates between the amino acids of the protein allowing it to be visualized on the gel Disrupts hydrogen bonding in proteins, linearizing the protein Provides an overall negative charge on proteins, making the migration distance on gel a function of only protein size
Disrupts hydrogen bonding in proteins, linearizing the protein Provides an overall negative charge on proteins, making the migration distance on gel a function of only protein size
Which microscope has a lens that works like the zoom lens of a camera?
Dissecting Microscope
What is the purpose of sodium carbonate in this lab?
Drastically changes the pH to stop the enzymatic reaction
Which of the below statements is true about the process of PCR? The reverse primer is identical to the reference strand. The reverse primer is extended in the 5' to 3'direction following the reference strand. The forward primer binds to the reference strand. During PCR, the primers will be extended from the 5' end. During PCR, the primers will be extended from the 3' end.
During PCR, the primers will be extended from the 3' end.
The organism in which this enzyme will be analyzed in this lab(B-galactosidase assay) is ___________.
E.coli
According to the lab safety sheet, the water used for the fish is treated with all of the following chemicals except: - sodium bicorbinate -EDTA - Sodium thiosulfate pentahydrate - Aliphatic amine salts -All of these chemicals are used.
EDTA
According to the Research Information Sheet, you will be paid for participating in this study
False
In the b-galactosidase assay lab, used microcentrifuge tubes and pipette tips contaminated with E. coli should be disposed of in the regular trash.
False
T/F: The MIT measures intelligence
False
According to the Research Information Sheet, possible risks you assume while participating in the Memory Interference Test (MIT) include: - Fatigue/Tiredness - None of these - Broken bones - All of these _ head Injuries
Fatigue/Tiredness
If money and space wasn't a problem, would it be better to use cows rather than goldfish to experiment on metabolism?
Fish, because their metabolic rate changes faster over time.
Which of the following is not an objective of the handgrip strength exercise? Correlate grip strength to gender and other physical characteristics Compare the pinch strengths of individual fingers in dominant and non-dominant hands Measure arm muscle strength in correlation to capacity to dead weight lifting Measure and compare the strength of your right and left hands
Measure arm muscle strength in correlation to capacity to dead weight lifting
Median
Median is the measurement located at the middle of the ordered set of data. - if the sample size is even, the median is the average between the two middle measurements.
What does MIT stand for?
Memory interference test
Which of the following is the description of skin viewed under a microscope? Large dark purple areas that are shaped in a circular pattern Multi-nucleated cells with striation Multi-layers with dark purple color on the superficial layer Large homogenous areas with light-pink staining
Multi-layers with dark purple color on the superficial layer
absorption and purity
Nucleic acid absorbs light mostly at 260 nm of wavelength, while protein does so at 280 nm . When the absorption ratio of 260 nm/280 nm is high (>1 .8), it indicates good nucleic acid purity .
what is used as a substrate rather than lactose in bgal lab?
ONPG, colorless but when cleaved will produce a yellow compound 420 nm in the spectrophotometer
Suppose you want to test if people who drink 5 cups of coffee per day perform differently on the MIT than those who do not drink coffee. What would your null hypothesis be?
People who drink 5 cups of coffee per day perform the same on the MIT than those who do not drink coffee.
Which of these sensors will allow you to determine an individual's forced vital capacity (FVC)? EKG/EMG sensor Spirometer Hand grip heart rate monitor Dynamometer
Spirometer
In the Agarose and Polyacrylamide Gels lab, when working with your protein or DNA sample you must wear: (check all that apply): Standard lab attire Safety goggles Lab coat Gloves Full-face air purifying respirator
Standard lab attire Safety goggles Lab coat Gloves
In DNA sequencing, how does the addition of dideoxynucleoside triphosphates (ddNTPs) terminate the synthesis of new DNA?
The ddNTPs have a hydrogen instead of a hydroxyl group at the 3' end, which prevents the addition of nucleotides.
serial dilution
Serial dilutions are an accurate and consistent method of reliably diluting a solution - the spectrophotometer has limits and, therefore, a concentrated sample must sometimes be diluted in order to get an accurate reading .
According to the lab safety sheet, if you get treated "fish water" in your eyes you don't have to rinse them because the water used for fish is non-toxic.
false
Because the rate of gas consumption will be measured, taking into account the mass of the organism will not have an effect on the interpretation of the data.
false
If a slide is broken you can throw the pieces in the regular trash as long as they are small.
false
In the Metabolism in Goldfish lab, you must wear gloves to handle the fish.
false
In this lab, the purpose of spectrophotometry is to measure protein activity.
false
Mitochondrial DNA can be inherited from either an individual's father OR mother.
false
Since we will be measuring the rate of metabolism, it will be unnecessary to monitor the behavior of the organism.
false
You can remove your lab coat once you are done with the wet lab portion of the DNA Isolation experiment, even if other people in the room are still working with Chelex.
false
You must wear a lab coat for this lab.
false
Which of these is not a tissue type that you must match to a slide in the LS23L histology lab?
fat
Agarose gel electrophoresis as used in the lab you will be performing this week can do all of the following EXCEPT: confirm the presence of purified DNA visually give a qualitative overview of the DNA purity show whether the DNA product is composed primarily of primer-dimer show whether the DNA is the correct size give a sequence for the amplified DNA
give a sequence for the amplified DNA
A 260nm/280nm spectrophotometer absorption ratio of 1.8 - 2.0 indicates which of the following? The size of the protein Good protein purity The size of the DNA Good nucleic acid purity How many subunits the protein contains
good nucleic acid purity
Suppose a woman with haplotype L1 and a man with haplotype L2 have a son. The son then marries a woman with haplotype L3. If this couple had one son and one daughter, what would be the respective haplotypes for their son and the daughter?
l3 and l3
What is the natural substrate of beta-galactosidase?
lactose
Mass spectrometry identities molecules based on their...
mass and charge
symmetrical unimodal distribution
mean = median = mode
symmetrical bimodal distribution
mean = median, with 2 modes Bimodal distributions may also be asymmetrical (mean, median), & multimodal distributions are possible.
n epidemiology, a population that has never been exposed to a virus of interest and is not vaccinated for it is known as a(n)...
naive population
After the treatment of proteins described in the lab manual, all proteins used in this lab should carry an overall __________ charge.
negative
OD420
optical density (absorbance) of a sample at 420 nanometers and is proportional to the amount of o-nitrophenol produces
OD600
optical density of a sample at 600 nanometers; it provides an estimate of cell density in the sample (the number of cells/ml) OD600 = 1 means 2 x 108 cells/ml
metabolic rate can be influenced by
oxygen temp size age condition environment activity
What is measured in the goldfish metabolism experiment as an indicator of metabolism?
oxygen concentration
Which of these is not a variable that is mentioned as one that can be tested in this lab? a. Caffeine b. pH c. salinity d. nicotine e. light/darkness
ph
Gold fish are
poikiolothermic whose body temp changes with the envrionment
Which type of gel is used in DNA sequencing?
polyacrylamide
protein gels use which type of gels
polyacrylamine
To aspirate with the pipetter:
press the pushbutton to the first stop, insert the pipette tip into liquid, and release pushbutton slowly.
spectrophotometry
provide a quantitative measure of the concentration of the DNA .
Gel filtration
provides an estimate of the molecular weight of the protein in its "native" state, i .e ., its intact and functional form .
general warming increases the rate of an enzyme catalyzed reaction
reaction rate rises with increasing temp
The reducing agent, b-mercaptoethanol, in SDS-PAGE: oxidizes disulfide bonds which dissociates protein subunits. intercalates into proteins making them visible under UV light. makes disulfide linkages visible under UV light. reduces disulfide bonds which denatures the protein. enzymatically cleaves disulfide linkages.
reduces disulfide bonds which denatures the protein
The MIT database gives a t-test value of 2.581, which correspond to a p-value of 0.01 for your null hypothesis. According to the hypothetico-deductive approach, what is the next step you should take? - Make new observations about your populations. - Calculate the standard deviation of the populations. - Use inferential statistics to compare the populations. - Fail to reject your null hypothesis. - Reject your null hypothesis
reject your null hypothesis
where does the energy for metabolic processes come from?
respiration
Who is the scientist for whom the dideoxy sequencing method is named?
sanger
Which of the following is not required for PCR? - Buffer solution - sequencing primer - Two primers that bind to denatured genomic DNA at complementary sequences - Taq polymerase -dNTPs
sequencing primer
how are proteins visualized?
staining
In the histology lab you must wear: (check all that apply)
standard lab attire
A researcher conducts 2 runs of SDS-PAGE on a protein with a molecular weight of 120 kD. For the first run he treats the protein with only SDS and for the second run he treats the protein with both SDS and a reducing agent. If the first run yields one band showing a molecular weight of 120 kD and the second run yields one band showing a molecular weight of 60 kD, the researcher should conclude that: the protein can have a weight of either 120 kD or 60 kD, depending on how it is folded. the protein contains no disulfide linkages. the protein consists of 2 subunits of equal size connected by a disulfide linkage. the protein contains only covalent bonds and no noncovalent interactions. the protein has only 1 subunit because both runs yield only 1 band.
the protein consists of 2 subunits of equal size connected by a disulfide linkage.
Sample
the set of measurements (X1, X2, X3, ... Xi) actually made
Which of the following statements concerning compound microscopes is FALSE? the compound microscope is composed of two lenses there are various levels of discreet magnification in a compound microscope the image produced is a mirror to what is actually observed light passes through the speciment into the viewer's eye the specimen must be dead in order to observed
the specimen must be dead in order to observed
chemical activity
the sum of all anabolic and catabolic processes
the forces that stabilize the interaction between subunits
they contain closely packed nonpolar sidechains, hydrogen bonds, and in some cases intermolecular disulfide bonds .
By definition, histology is the study of:
tissues
According to the lab safety sheet, cotton swabs, gloves, sponges and petri dishes potentially contaminated with bacteria must be placed in the autoclave waste container.
true
According to the lab safety sheet, in the Agarose and Polyacrylamide Gels lab, used microcentrifuge tubes and pipette tips should be disposed of in the regular trash.
true
According to the lab safety sheet, in the Epidemiology & Laboratory Techniques lab all microcentrifuge tubes, pipette tips and cuvettes used during the pipetting exercises and at the practice stations can be disposed of in the regular trash.
true
During Sanger sequencing, ddNTPs are labeled with fluorescent dyes in order to differentiate between the different nucleotides. Correct!
true
Larger specimens should be examined using the dissecting microscope.
true
The fish metabolism experiment will be performed by placing fish in the test chamber and observe change in gas concentration through time.
true
The instrument that you will use in this goldfish lab needs to be warmed up before use.
true
There are many alternative ways to analyze and present the data gathered from this experiment.
true
There are no chemicals used in the Histology lab.
true
There is no hazardous waste disposal for this lab.
true
When writing your report, you must generate a testable hypothesis and use the online database to test it.
true
mtDNA is more abundant per cell than nuclear DNA.
true
Spectrophotometry
used to accurately determine the concentration of DNA, RNA, or protein in a sample . The spectrophotometer works by irradiating a sample containing the compound(s) of interest with monochromatic beams of light at specific wavelengths . The absorption at any given wavelength is determined by measuring the difference in the signal with and without the presence of the compound of interest .
In an EKG reading, what occurs during the QRS complex? conductance and sequential depolarization of the ventricles initiation of depolarization in the sinus node and subsequent atrial contraction period of time in which the ventricles are isoelectric repolarization of the ventricles
conductance and sequential depolarization of the ventricles
The process of identifying individuals that may have been exposed to an infectious individual in order to quarantine them is known as
contact training
What part of the pipetter is indicated by the label "E" in the diagram below?
e
What is the name of the output image of the Sanger sequencing process?
electropherogram
PCR (polymerase chain reaction)
A laboratory technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.
Which interval/segment observed via EKG sensor can be used to calculate the heart rate? QRS Complex PR Segment QT Interval RR Interval PR Interval
RR interval
Electrophoresis
-confirms the presence of purified DNA visually and gives a qualitative overview of the DNA purity . - can also show whether the amplified DNA is the correct size, or composed primarily of primer-dimer .
A closed system used in the oxygen chamber for the metabolism lab ensures that: - extends the life of an organism. -enough gases are exchanged between different systems. -no gases are exchanged in order to monitor how the organism reacts in a low oxygen condition. - the organism has enough chemicals in order to live. -no gases are exchanged in order to monitor the production or concumption of oxygen within the system.
-no gases are exchanged in order to monitor the production or concumption of oxygen within the system.
P1000
100-1000uL -middle digit = hundreds of uL and lowest digit tens e.g. 010 (read top to bottom) is 100 uL
1 milliliter (ml) is equal to how many microliters (μl)?
1000
What is the ratio of ddNTP to dNTP in the nucleotide mixture for the Sanger sequencing reaction?
1ddNTP to 50 dNTP
P20
2-20 ul -top digit: tens of uL -middle digit: individual uL -bottom digit: tenths of uL -reading 020 = 2 ul
P200
20-200 ul
What is the maximum volume you can safely and accurately pipet with a p200 pipetter?
200 μl
You are performing a biochemical assay of b-galactosidase activity. Test Tube A contains 4.0 ml of Luria Broth (LB). Test Tube B contains 3.6 ml of LB and 400 ul of 4% lactose. You pipette 400 ul of E. coli bacteria into each test tube, mix them, and incubate them for 20 minutes. After this incubation period, you retrieve two microcentrifuge tubes and the provided b-gal blank. You remove 200 ul each from Test Tubes A and B and add it to your labeled microcentrifuge tubes, then add 10 uL of PopCulture and allow it to incubate before adding 600 uL of Z-buffer mix. Later in the assay, you will measure the optical densities of these mixtures at 420nm after adding the appropriate substances (ONPG, and Na2CO3) and closely following the procedures. Which volume would you use in your calculation of units of enzyme activity?
200ul
What is the minimum volume you can safely and accurately pipet with a p200 pipetter?
20ul
Lipase
30-40 c Lipase is an enzyme the body uses to break down fats in food so they can be absorbed in the intestines
How many rounds of handshaking will the epidemiology exercise have?
4
In Sanger DNA sequencing, how many different fluorescent dyes are used to label ddNTPs?
4
Assume you are patient zero (i.e. infected with bacteria) in the epidemiology lab and there were two rounds of handshakes. If you shook hands with two uninfected persons the first round, and each of them shook hands with two more uninfected persons the second round, how many total people would be infected including yourself? You did not shake hands with anyone else in the second round and there were no double-infections.
7
What characteristic defines a good primer design?
A combination of guanine and cytosines at the 3' end because this increases specificity
All the following are similarities between EKG and EMG, except: Both generate graphical representations of activity Both require electrodes to be in direct contact with the skin Both require the same placement on the body Both measure electrical events in tissue
Both require the same placement on the body
According to the lab safety sheet, which of the following is a potential hazard you will face in the Agarose and Polyacrylamide Gels lab? (Check all that apply) Chemicals causing respiratory tract, eye and skin irritation None of these Carcinogenic (cancer causing) chemicals Water reactive chemicals Corrosive chemicals
Chemicals causing respiratory tract, eye and skin irritation
Which of these substances is usually used to visualize proteins on a polyacrylamide gel?
Coomassie blue
Which of the following is not an objective of using the heart rate monitor in this lab? Determine the effects of exercise on heart rate Observe pulse response to sudden standing from squatting position Observe an example of sympathetic nervous system activation Determine the presence of tachycardia and other abnormalities of heart rhythmicity
Determine the presence of tachycardia and other abnormalities of heart rhythmicity
What is the special property of Taq polymerase that allows it to work in PCR?
It is heat resistant.
What physiological activity will we not be measuring in this lab? Heart rate changes Lung volumes Kidney filtration Muscle electrical activity
Kidney filtration
A student has obtained an unknown tertiary protein. Which of the following can the student do to determine both the molecular weight of the native protein and the total number of subunits in the protein? Run a SDS-PAGE with coomasie blue and b-mercaptoethanol followed by X-ray crystallography Run a SDS-PAGE after mixing the protein with coomassie blue and perform a Western Blot Run a PAGE after denaturing the protein in SDS and perform ultracentrifugation through a glucose gradient using flourescein isothiocyanate (FITC) Perform ultracentrufigation to determine the total mass of the native protein and use gel filtration to determine the number of subunits within in the protein Perform gel filtration and run a SDS-PAGE after mixing the protein with b-mercaptoethanol
Perform gel filtration and run a SDS-PAGE after mixing the protein with b-mercaptoethanol
Which of the following is not a type of MIT that may be taken? - Number - Picture -Physical -Word - All of these can be taken
Physical
How do you release the excess solution that remains at the pipette tip after pushing to the first stop?
Press the push button down to the second stop to complete expulsion
When you design primer pairs for PCR, several factors need to be considered. Which of the following is false? - Cytosine (C) and Guanine (G) should make up 50-60% of the total base pairs. - Primers can fold back onto themselves. - Primers should end (3') in a G or C, or CG or GC. - Primers that are 6 base pairs long can be very specific in amplifying the target genes. - Primers can bind to another primer.
Primers that are 6 base pairs long can be very specific in amplifying the target genes.
In a recording of an EKG, which part of the graph represents ventricular contraction? PR segment ST segment QRS complex PR interval QT interval
QRS complex
According to the Lab Safety Sheet provided for this week, which of the following is a potential hazard you will face in the b-galactosidase assay lab?
RG1 Bacteria
What is the purpose of ONPG in this lab?
Substrate that gives a yellow color when cleaved
Some of the chemicals/materials you will use in the Polyacrylamide and Agarose Gels lab include (check all that apply): Chloroform TGS (tris-glycine-SDS) buffer Ethidium bromide None of these Tris glycine polyacrylamide gels
TGS Bufffer Tris glycine polycacrylamide gels
The traditional Sanger Method, or Dideoxy Method, of DNA sequencing differs from DNA sequencing methods and visualization techniques most often used today in which of the following ways?
The Sanger method uses radiolabeling of DNA for visualization on electrophoresis with reactions using different ddNTPs, while modern methods use fluroescent color tags to visualize the sequence in an electropherogram.
During Sanger sequencing, ddNTPs are labeled with fluorescent dyes in order to differentiate between the different nucleotides.
True
SDS-polyacrylamide gel electrophoresis (SDS-PAGE)
Type of electrophoresis in which the protein mixture to be separated is run through a gel containing the detergent sodium dodecyl sulfate (SDS) which unfolds the proteins and frees them from association with other molecules.
Chelex
USED TO PREVENT DNA DEGRADATION used to bind all Mg2+ so enzymes that degrade DNA cannot function enzymes that degrade DNA need Mg2+ to function
Which of the following statements is false regarding the B-galactosidase assay lab?
Using the spectrophotometer, we measured cell density at 420 nm and B-galactosidase activity at 600 nm.
Biochemical assay
asses how much of a given protein ( enzyme) is produced per cell, per unit of time
In mitochondrial lab, DNA will be collected from
cheek cells/saliva
According to the LS Core Lab Safety Sheet for this lab, which of the following is a potential hazard you will face in the DNA Isolation lab?
chemicals causing eye irritation
t- test
determines the difference between two samples by comparing their means while taking into account their variances.
The t-test takes into account the ________ and ________ of the data, and the p-value tells us ________.
difference in means, variance, whether the difference between the two groups is statistically significant.
If the results of an experiment allow one to reject the null hypothesis, then: - too few trials per treatment were performed. - the control and experimental treatments differ significantly with respect to the variable being studied. - the null hypothesis correctly predicts the outcome of the experiment. - the control and experimental treatments do not differ significantly with respect to the variable being studied. - the experiment lacked adequate controls.
the control and experimental treatments differ significantly with respect to the variable being studied.
Population
the entire collection of measurements on which the researcher intends to draw conclusions
migration through an electrical field depends on
the net charge, the size and shape of the molecules, and the strength of the electric field .
In an experiment, running a single trial per treatment is not good science because: (Select all that apply) -you do not know if your results are repeatable and therefore reliable. -just by chance you may observe a difference between your treatments when one really does not exist. -you lack a null hypothesis. -the results will be confounded by manipulating too many variables at one time.
you do not know if your results are repeatable and therefore reliable. -just by chance you may observe a difference between your treatments when one really does not exist.