LS23L Final Exam

Lab A

Scientific Methodology and the MIT

Which of the following is an example of a null hypothesis?

Select one:
a. Those that consume caffeine regularly will have a higher heart rate than those that do not.
b. People of Asian descent and people of European descent perform the same on IQ tests.
c. Male humans perform better on memory tests compared to female humans.
d. All tigers are carnivores.
e. Giraffes have long necks because they feed on the leaves of tall plants.

b. People of Asian descent and people of European descent perform the same on IQ tests.

Which of the following statements about the p value is true?

Select one:
a. It allows you to determine the t-value needed for rejecting or accepting the null hypothesis.
b. It gives the probability that you are making a mistake in accepting the experimental null hypothesis.
c. Only a p value smaller than 0.5 is statistically significant.
d. The larger the p value, the more significant your results are.
e. It gives the probability that you are making a mistake in accepting the experimental hypothesis.

e. It gives the probability that you are making a mistake in accepting the experimental hypothesis.

If a student claims that females answered on average a greater number of correct responses than males on the picture MIT test, what evidence does the student need to gather in order to better support this hypothesis?

Select one:
a. Verify that the standard deviation is greater than 5
b. See if the degrees of freedom is greater than 1,000
c. Check if the T-value is greater than 0.05
d. Show that the null hypothesis has a high probability of being incorrect
e. Check if the T-value is 5% or less

d. Show that the null hypothesis has a high probability of being incorrect

A scientist is interested in studying the parasite responsible for malaria and wants to study the effects of different variables on the parasite's ability to cause disease. She hypothesizes that the parasite is more pathogenic in environments containing glucose. Which of the following most accurately captures the null hypothesis of her experiment?

Select one:
a. The parasite cannot use glucose
b. The parasite is less pathogenic in environments without glucose.
c. The parasite switches modes of metabolism in the presence of lactose.
d. The parasite is more pathogenic in environments with high glucose levels.
e. The parasite's pathogenicity is not affected by environmental glucose levels.

e. The parasite's pathogenicity is not affected by environmental glucose levels.

In a recent study, scientists proposed the following hypothesis: "Consumption of Omega-3 fatty acid can reduce the size of cancerous tumors." The following hypothesis was tested. A sample of 500 rats with tumors was collected. Within this sample size, 250 rats were fed with omega-3 (Group 1) while the remaining 250 rats were not (Group 2). After one month of periodically feeding Group 1 with Omega-3 fatty acid, rat autopsies were taken for both groups. The average changes of tumor size were measured and recorded.
Average Change in Tumor Size
Group 1: -0.124 g
Group 2: -0.012 g
Degrees of Freedom: 498
T-test: 2.061
P-value: 0.04
Based on the results from the experiment, which of the following is the best conclusion?

Select one:
a. Consumption of Omega-3 fatty acid has no effect on decreasing the size of previous cancerous tumors.
b. Consumption of Omega-3 fatty acid decreases the size of previous cancerous tumors with statistical significance.
c. Consumption of Omega-3 fatty acid directly decreases the size of previous cancerous tumors.
d. Absence of Omega-3 fatty acid in the diet directly decreases the size of previous cancerous tumors.
e. Absence of Omega-3 fatty acid in the diet decreases the size of previous cancerous tumors with statistical significance.

b. Consumption of Omega-3 fatty acid decreases the size of previous cancerous tumors with statistical significance.

In order to reject the null hypothesis in the Memory Interference Test (MIT) lab

Select one:
a. The t-test value must be less than 0.05
b. The p value must be less than 0.05
c. Both the p value and the t-test value must be less than 0.05
d. The t-test value must be greater than 0.05
e. The p value must be greater than 0.05

b. The p value must be less than 0.05

What is the difference between a p-value and t-value?

Select one:
a. All of these statements are correct
b. The t-value tells you the probability that the null hypothesis is correct while the p-value is the first step to finding the t-value.
c. The p-value tells you the probability that the null hypothesis is correct while the t-value is the first step to finding the p-value.
d. There is no difference between the two values
e. The t-value gives you a value between 0 and 1 while the p-value does not have a range of numbers.

c. The p-value tells you the probability that the null hypothesis is correct while the t-value is the first step to finding the p-value.

As a statistician, you conducted an experiment and obtained a t-test value for the two experimental groups. At a confidence level of 5 percent, the corresponding statistical p-value of 0.067 would suggest that:

Select one:
a. The inherent error of the experiment is calculated to be 6.7 percent.
b. The two experimental groups are statistically identical.
c. There is a 6.7 percent probability that you are making a mistake by failing to reject the null hypothesis.
d. There is a 6.7 percent probability that you are making a mistake in accepting the experimental hypothesis.
e. There is probably a statistically significant difference between the two groups of interest.

d. There is a 6.7 percent probability that you are making a mistake in accepting the experimental hypothesis.

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?

Select one:
a. Use inferential statistics to compare the populations.
b. Make new observations about your populations.
c. Retain your null hypothesis.
d. Reject your null hypothesis.
e. Calculate the standard deviation of the populations.

d. Reject your null hypothesis.

When performing a statistical analysis test, why do we usually work with a sample rather than an entire population?

Select one:
a. A t-test doesn't product results when a population is used.
b. We don't work with samples, we only work with entire populations.
c. We often lack the manpower and resources to gather an entire population for a statistical analysis.
d. The p-values only work with samples, not populations

c. We often lack the manpower and resources to gather an entire population for a statistical analysis.

After comparing response times between the audio and picture portions of the MIT test, the t-test resulted in a t-value of 2.97. Given that the sample size was 250 and the t-value at p=0.05 is 1.96, what can I conclude from this data?

Select one:
a. Reject the null hypothesis, the p-value is less than 0.05. Therefore, the difference is significant.
b. We cannot conclude anything because the sample size is too small.
c. Accept the null hypothesis, the sample size is large enough.
d. Reject the hypothesis, the p-value is less than 0.05. Therefore, the difference is significant.
e. Accept the hypothesis, the sample size is too small

a. Reject the null hypothesis, the p-value is less than 0.05. Therefore, the difference is significant.

You are designing an experiment to compare the average metabolic rate of right-handed people to the average metabolic rate of left-handed people. Which of the following would be an appropriate null hypothesis for your experiment?

Select one:
a. Average metabolic rate depends on whether an individual is right-handed or left-handed.
b. A comparison of the average metabolic rate of left-handed people to the average metabolic rate of right-handed people shows a significant difference.
c. There is no difference between the metabolic rate of left-handed people and the average metabolic rate of right-handed people.
d. Left-handed people have a higher average metabolic rate than right-handed people.
e. On average, left-handed people have a comparably lower average metabolic rate than right-handed people.

c. There is no difference between the metabolic rate of left-handed people and the average metabolic rate of right-handed people.

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?

Select one:
a. The mean, median and mode are the same value.
b. The mode and median are the same value, but not the mean.
c. The median and mean are the same value, but not the mode.
d. The mean, median, and mode are not the same value.
e. The mean and mode are the same value, but not the median.

a. The mean, median and mode are the same value.

Which of the following can NEVER be a measure of central tendency?

Select one:
a. Mean.
b. Median.
c. Both mode AND standard deviation.
d. Mode.
e. Standard deviation.

e. Standard deviation.

Lab B

Epidemiology and Lab Techniques

1 milligram (mg) is equal to how many micrograms (μg)?

Select one:
a. 0.1
b. 1
c. 10
d. 100
e. 1000

e. 1000

When ejecting a protein sample into a well of the SDS-PAGE gel with a pipetter, why should you only push down on the pushbutton to the first stop and not the second stop?

Select one:
a. The pushbutton should only be pushed down to the second stop when loading the sample into the pipetter.
b. Pushing down to the second stop when loading the samples will not affect the SDS-PAGE results.
c. Pushing down to the second stop will eject more sample than required.
d. Pushing down to the second stop could denature the protein sample.
e. Pushing down to the second stop will result in ejection of air from the pipet tip, which could blow the content intended for that particular well to the surrounding wells.

e. Pushing down to the second stop will result in ejection of air from the pipet tip, which could blow the content intended for that particular well to the surrounding wells.

If you are asked to pipet 240 microliters of colored water, which pipetter would you use and what is the proper setting in each volumeter window? (top, middle, bottom)

Select one:
a. p20 (2,4,0)
b. p200 (0,2,4)
c. p1000 (0,2,4)
d. p200 (2,4,0)
e. p1000 (2,4,0)

c. p1000 (0,2,4)

To aspirate with the pipetter,

Select one:
a. press the pushbutton to the second stop, insert into liquid, and release the pushbutton slowly.
b. press the pushbutton to the first stop, insert into liquid, and release pushbutton slowly.
c. press the pushbutton to the first stop.
d. press the pushbutton to the second stop.
e. press the pushbutton to the second stop, insert into liquid, and release slowly to the first stop.

b. press the pushbutton to the first stop, insert into liquid, and release pushbutton slowly.

_____________ is the rapid spread of disease to a large population over a short period of time, and ____________ is when ___________ strikes at a global scale.

Select one:
a. Outbreak, epidemic, pandemic
b. Pandemic, epidemic, pandemic
c. Epidemic, pandemic, epidemic
d. Epidemiology, pandemic, epidemic
e. Outbreak, epidemiology, pandemic

c. Epidemic, pandemic, epidemic

What is the purpose of having to press the push button of a pipetter to the second stop?

Select one:
a. to expel any remaining liquid
b. to aspirate any remaining liquid
c. to eject the pipette tip
d. to make sure the solution is mixed well
e. to assure a larger absorbance reading

a. to expel any remaining liquid

Pipetters can dispense volumes accurately if the user

Select one:
a. presses the pushbutton to the second stop while tip is in liquid to expel out air in the tip and then release the pushbutton while tip is still in liquid to drawn up the right amount
b. dials down to the correct reading
c. dials up to the correct reading
d. shakes the tip with the liquid in it to expel possible air from the tip.
e. makes sure that the pushbutton is not shaking

b. dials down to the correct reading

Why is it most important to learn to use pipettes correctly?

Select one:
a. Pipettes can measure any volume with 100% accuracy
b. Pipettes are utilized in every person's every day life
c. Incorrect usage of pipettes can result in a low grade in LS3
d. Pipettes are an important and omnipresent piece of equipment in biology laboratories
e. Other individuals in a laboratory will expect you to know how to use pipettes.

d. Pipettes are an important and omnipresent piece of equipment in biology laboratories

By the end of the round 3 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?

Select one:
a. (8/24) x 100%
b. (14/24) x 100%
c. (15/24) x 100%
d. (16/24) x 100%
e. (24/24) x 100%

d. (16/24) x 100%

Why does all the equipment from the epidemiology lab get thrown into the autoclave waste as opposed to the regular waste?

Select one:
a. Lab sponges cannot be thrown into the regular trash.
b. Petri dishes cannot be disposed of in the autoclave waste.
c. It is unknown which sponge is infected, so they must all be discarded equally.
d. The gloves can be reused if they are autoclaved properly.
e. All of the sponges have bacteria, so they cannot be thrown in the regular trash.

c. It is unknown which sponge is infected, so they must all be discarded equally.

The picture shows a volumeter window for a p200 pipetter. It reads from top to bottom 025. What is the volume pipetted?

Select one:
a. 25 milliters
b. 25 microliters
c. 2.5 microliters
d. 2.5 milliliters
e. 0.25 milliliters

b. 25 microliters

Lab C

Biochemical Assay of Beta-Galactosidase Activity

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?

Select one:
a. 200 ul
b. 600 ul
c. 1.0 ml
d. 800 ul
e. 400 ul

a. 200 ul

In the B-galactosidase assay, PopCulture is added to __________.

Select one:
a. stop the reaction of B-galactosidase and ONPG by changing the pH from 7.0 to 11.0.
b. partially disrupt the cell membrane, allowing the cellular proteins to diffuse out of the cell.
c. provide essential nutrients for bacterial growth.
d. promote the reaction between B-galactosidase and ONPG by optimizing the pH sample.
e. change the pH of reaction from 7.0 to 4.0.

b. partially disrupt the cell membrane, allowing the cellular proteins to diffuse out of the cell.

In the b-galactosidase assay lab, the readings of each sample at 420nm using the spectrophotometer measures the amount of

Select one:
a. b-galactosidase in sample.
b. glucose in sample.
c. RNA polymerase in sample.
d. E. coli cells in sample.
e. o-nitrophenol in sample.

e. o-nitrophenol in sample.

If equal amounts of lactose and glucose are present, will there be b-galactosidase activity within 10 minutes of incubation?

Select one:
a. Yes, because both glucose and lactose are used equally.
b. Yes, because lactose is the preferred sugar source.
c. No, because glucose is the preferred sugar source.
d. No, because lactose is the preferred sugar source.
e. Yes, because glucose is the preferred sugar source.

c. No, because glucose is the preferred sugar source.

Which of the following should NOT be added to the B-galactosidase blank?

Select one:
a. ONPG.
b. Na2CO3.
c. E. coli cells.
d. Z buffer.
e. PopCulture

c. E. coli cells.

What event is MOST responsible for causing the conformational change in the lac repressor of E. Coli?

Select one:
a. Allolactose allosterically binds to the lac repressor, causing a conformational change
b. The increase in cell density over time causes their to be more lac operons than there are repressors
c. ONPG interferes with the lac repressor's ability to bind the operator
d. the presence of glucose causes a conformational change in RNA polymerase which allows it to carry out transcription
e. enough time has passed since the end of mitosis and the cell is ready to begin transcription

a. Allolactose allosterically binds to the lac repressor, causing a conformational change

In the b-galactosidase lab, one would expect that:

Select one:
a. the tube containing LB + no lactose + cells turns yellow because b-galactosidase doesn't cleave ONPG.
b. the tube containing LB + lactose + cells turns yellow because b-galactosidase doesn't cleave ONPG.
c. the tube containing LB + lactose + cells turns yellow because beta- galactosidase cleaves ONPG.
d. the tube containing LB + glucose + cells turns yellow because b-galactosidase cleaves ONPG.
e. the tube containing LB + no lactose + cells turns yellow because beta- galactosidase doesn't cleave lactose.

c. the tube containing LB + lactose + cells turns yellow because beta- galactosidase cleaves ONPG.

John wants to measure the activity of B-galactosidase using the same protocol followed by LS23L students. He performs the experiment correctly but instead of ONPG he mistakenly adds galactose to the cells. How will his spectrophotometry results compare to those obtained with ONPG?

Select one:
a. The OD600 will be higher because ONPG stops cell growth.
b. The OD420 be the same because B-galactosidase is not produced in the presence of galactose.
c. The OD600 will be lower because the cells need glucose to survive.
d. The OD420 be lower because it measures the presence of products from the breakdown of ONPG.
e. The OD420 will be higher because galactose is a product of B-galactosidase activity.

d. The OD420 be lower because it measures the presence of products from the breakdown of ONPG.

In the presence of glucose, Beta-galactosidase

Select one:
a. does not have to be produced because there is no need for it
b. cleaves glucose into lactose without using ATP
c. produces ATP used for cellular respiration
d. cleaves glucose into galactose by using ATP
e. binds to ONPG which in turn facilitates glucose breakdown

a. does not have to be produced because there is no need for it

The lac operon is devised to activate the transcription of the enzyme beta-galactosidase when needed. What conditions begin this process?

Select one:
a. Glucose is required to provide for the mRNA translation.
b. Presence of Glucose yield energy for the cell to use in order to produce the beta-galactosidase enzyme.
c. The lac repressor is deactivated through allosteric change in the presence of lactose allowing for transcription of the Z Gene to beta-galactosidase.
d. The RNA polymerase will bind to the Promoter region when lactose is present.
e. The Lac-Z gene will only be functional during the presence of Lactose.

c. The lac repressor is deactivated through allosteric change in the presence of lactose allowing for transcription of the Z Gene to beta-galactosidase.

The enzyme beta-galactosidase breaks down ______ into simpler sugars ________ and ________ .

Select one:
a. Sucrose, sucrose, galactose.
b. Lactase, glucose, galactose.
c. Lactose, glucose, galactose.
d. Fructose, glucose, lactose.
e. Lactose, glucose, galactosidase.

c. Lactose, glucose, galactose.

As defined in this lab, units of beta-galactosidase activity

Select one:
a. describes the amount of lactose produced per E. coli cell per minute.
b. describes the amount of o-nitrophenol produced per E. coli cell per minute.
c. describes the amount of ONPG produced per E. coli cell per minute.
d. is a good indicator of b-galactosidase activity, because it does NOT consider cell density.
e. describes the amount of b-galactosidase produced per E. coli cell per minute.

b. describes the amount of o-nitrophenol produced per E. coli cell per minute.

Which of the following is not a component of the lac operon in E. coli?

Select one:
a. operator
b. Lac Z gene for beta galactosidase
c. Lac A gene for thiogalactosidase transacetylase
d. Lac I gene for lac repressor
e. promoter

d. Lac I gene for lac repressor

What is a conclusion that can be gained from the lab on beta galactosidase?

Select one:
a. beta galactosidase synthesis does not require glucose and is time dependent
b. beta galactosidase synthesis requires glucose and is time dependent
c. beta galactosidase synthesis requires lactose and is not time dependent
d. beta galactosidase synthesis requires glucose and is not time dependent
e. beta galactosidase synthesis does not require lactose and is not time dependent

a. beta galactosidase synthesis does not require glucose and is time dependent

What is a useful substrate for assaying b galactosidase activity and why?

Select one:
a. ONPG because it produces a yellow compound that can be read at 420 nm in a spectrophotometer after it is cleaved
b. ONPG a b galactosidase derivative because it is a yellow compound that can be read at 420 nm in a spectrophotometer
c. o-nitrophenol because it is a direct derivative of lactose and turns yellow after cleavage by b galactosidase
d z buffer because it promotes the reaction between b galactosidase and ONPG
e. o-nitrophenol because it changes the ph from 7 to 11 and facilitates the reaction between b galactosidase and ONPG

a. ONPG because it produces a yellow compound that can be read at 420 nm in a spectrophotometer after it is cleaved

Lab D

Metabolism in Goldfish

Which of the following is the best reason explaining why goldfish is a good experimental specimen?

Select one:
a. Long lifetime
b. Small body masses
c. Small ectotherms that respond well to environmental changes
d. Mates quickly and has a high fecundity
e. Simple genetics and body composition

c. Small ectotherms that respond well to environmental changes

What characteristic about goldfish make them a good test subject for the metabolism lab?

Select one:
a. they are homeotherms, making their metabolic rates easier to manipulate since their body temperature stays constant despite the environmental temperature.
b. they are poikilothermic, making their metabolic rates easier to manipulate since their body temperature changes with the environmental temperature.
c. they are small in size, making it easier to track their oxygen consumption rate.
d. their bodies are not easily influenced by external factors such as temperature or exposure to light
e. their metabolic activity (anabolic and catabolic pathways) uses energy from glycolysis which can be tracked through oxygen consumption

b. they are poikilothermic, making their metabolic rates easier to manipulate since their body temperature changes with the environmental temperature.

Which of the following statements is true about the control and experimental trials each set of fish must undergo in this metabolism lab?

Select one:
a. Each set of fish should undergo both a control and an experimental trial, because otherwise it wouldn't be fair for the fish.
b. One set of fish should undergo two control trials, and the other set should undergo two experimental trials because this keeps your results consistent.
c. As long as there are two control trials and two experimental trials, it does not matter what combination of trials each set of fish undergoes -- there's no effect on the results of the experiment.
d. One set of fish should undergo two control trials, and the other set should undergo two experimental trials because doing so is less stressful on the poikilothermic fish.
e. Each set of fish should undergo both a control and an experimental trial, because doing so would make it possible to test the effects on the metabolic rate caused by the single variable introduced in the experimental trial by itself. The effects of confounding factors, such as differences in the two sets of fish, are thus minimized.

e. Each set of fish should undergo both a control and an experimental trial, because doing so would make it possible to test the effects on the metabolic rate caused by the single variable introduced in the experimental trial by itself. The effects of confounding factors, such as differences in the two sets of fish, are thus minimized.

Which of these metabolic processes is an anabolic process?

Select one:
a. triglyceride turns into one glycerol and three fatty acids
b. sucrose breaks into fructose and glucose
c. glycogen becomes many glucose molecules
d. starch forms maltose molecules
e. valine and tryptophan form a small peptide

e. valine and tryptophan form a small peptide

Which of the following is true regarding the metabolism in animals?

Select one:
a. Metabolism is the total chemical activity, which is the sum of all anabolic and catabolic processes.
b. Metabolic Rate is not influenced by an organism's body temperature.
c. Poikilotherm organisms do not have any effect in body temperature when their enviornment temperature changes.
d. Through respiration, organisms obtain oxygen, whose rate is inversely proportional with the metabolic rate.
e. The Anabolic Pathways serve to break down molecules while the Catabolic Pathways synthesize important chemical building blocks.

a. Metabolism is the total chemical activity, which is the sum of all anabolic and catabolic processes.

Why were fish used in the Metabolism experiment?

Select one:
a. Fish have a constant high body temperature and thus a high metabolic rate that can be measured.
b. Fish have a constant low body temperature and thus a low metabolic rate that can be measured.
c. Fish have a constant body temperature but a variable metabolic rate that is influenced by its environment.
d. Fish have a variable body temperature and metabolic rate that are influenced by the surroundings.

d. Fish have a variable body temperature and metabolic rate that are influenced by the surroundings.

There are several ways to measure the metabolic rate of an organism. All of these are reasons to use oxygen as a way to measure metabolic rate EXCEPT:

Select one:
a. The change in environment is reflected in the amount of oxygen consumed by the fish.
b. Oxygen consumption decreases the blood flow in the fish that has an effect on the metabolic rate.
c. Oxygen is a component of in the respiration pathway and is therefore related to the metabolic rate.
d. A sensor probe can easily detect the amount of oxygen in the water.
e. The closed system of the oxygen chamber allows the change in oxygen consumption to be measured.

b. Oxygen consumption decreases the blood flow in the fish that has an effect on the metabolic rate.

Which of the following statements is FALSE?

Select one:
a. Endotherms are less readily affected by changes in the environment.
b. Anabolic reactions are characterized by breakdown of complex molecules and energy release.
c. Experimental results can lead the experimenter to either 'accept' or 'reject' the Null Hypothesis.
d. A control provides a point of comparison to determine if variable of interest has an effect.
e. Homeostatic mechanisms of fishes and lizards are similar.

b. Anabolic reactions are characterized by breakdown of complex molecules and energy release.

Goldfish are used for the metabolism experiment for all of the following reasons, except:

Select one:
a. Their metabolism is affected by their environment
b. They are small
c. They are easy to use for an experiment
d. They can swim faster than other fish of the same size
e. They have a high surface area to volume ratio

d. They can swim faster than other fish of the same size

Which of the following is a reason for why we used goldfish as our model organism when studying metabolism in lab?

Select one:
a. Because the metabolic rate of goldfish is easier to manipulate.
b. Because goldfish are able to regulate their own body temperature.
c. Because environmental temperature changes do not affect the body temperature of goldfish.
d. Because goldfish are homeothermic organisms.
e. Because goldfish are able to withstand most types of substances such as Borax.

a. Because the metabolic rate of goldfish is easier to manipulate.

Small endotherms have higher respiration rates per gram of body mass than large endotherms because

Select one:
a. small endotherms move faster than large endotherms.
b. small endotherms have more insulation than large endotherms.
c. small endotherms move slower than large endotherms.
d. small endotherms have a lower surface to volume ratio than large endotherms.
e. small endotherms have a higher surface to volume ratio than large endotherms.

e. small endotherms have a higher surface to volume ratio than large endotherms.

Which of these is false regarding measuring metabolism in goldfish?

Select one:
a. goldfish are preferable compared to rats for manipulating metabolic rates because they are poikilothermic organisms
b. the amount of oxygen consumed can be an indicator of a goldfish's metabolic rate
c. weight and size of the goldfish have an effect on a goldfish's metabolic rate because they are aquatic organisms
d. goldfish are ideal for manipulating metabolic rates because their body temperature remains relatively constant despite environmental changes

d. goldfish are ideal for manipulating metabolic rates because their body temperature remains relatively constant despite environmental changes

For the metabolism lab, one of the primary reasons that we used fish for this experiment was because:

Select one:
a. they are poikilotherms
b. they are amphibians
c. they are anaerobic
d. they are homeotherms
e. they are holographic

a. they are poikilotherms

We conducted the metabolism experiment with 2 experimental trials using 2 fish in each trial. How many control fish did we need in total?

Select one:
a. one
b. none
c. four
d. six
e. two

c. four

Fluffy is a mammalian homeothermic Labrador puppy. She is unusual because she is more active at night than during the day. What inferences can you make about Fluffy's physiology?
I. Fluffy's catabolic rate is increased at night because she requires more energy at night
II. Fluffy's respiration is decreased at night, because fluffy requires more ATP at night
III. Fluffy's body temperature is lower at night because the environmental temperature is lower at night

Select one:
a. III
b. I & II
c. II & III
d. I
e. II

d. I

The metabolic rate is not influenced by which of the following criteria?

Select one:
a. weight of the organism
b. catabolic pathways
c. anabolic pathways
d. oxygen consumption
e. urine output

e. urine output

Which of the following terms and statements incorrectly describes a goldfish?

Select one:
a. Anabolic: this allows macromolecules within the goldfish to be built up
b. Poikilothermic: this allows environmental temperature to affect the metabolism of the goldfish
c. Catabolic: this allows macromolecules within the goldfish to be broken down
d. Metabolic: this allows chemical energy to be used in the physical processes of the goldfish
e. Homeothermic: this allows the consumption of oxygen to be measured in the goldfish

e. Homeothermic: this allows the consumption of oxygen to be measured in the goldfish

Making a flow chart before performing the experiment will help you do all these except ________ (find the one answer that is false).

Select one:
a. Minimize problems
b. Allow you perform various parts of your experiment
c. Execute the data analysis
d. Give you the results that you are looking for
e. Anticipate sources of error

d. Give you the results that you are looking for

Which of the following factors would be least significant in affecting the rate of oxygen consumption of goldfish?

Select one:
a. Metabolic rate of the goldfish.
b. Gender of the goldfish.
c. Temperature of the water.
d. Weight of the goldfish.
e. Chemical composition of the water.

b. Gender of the goldfish.

What is NOT one reason why we use fish to measure metabolism?

Select one:
a. They are ectotherms
b. They are fairly passive and do not move around too much
c. They have a high surface area to volume ratio
d. They are readily influenced by their environment

b. They are fairly passive and do not move around too much

Lab E

DNA Isolation and Amplification

Which specific part of the mitochondrial DNA did we amplify with PCR for determining the maternal lineage, and why?

Select one:
a. D-loop region, because this region contains the ori site, where replication begins.
b. HVS I (Hyper Variable Segment I), because this segment encodes for proteins, which can accumulate more mutations and affect function.
c. HVS I (Hyper Variable Segment I), because this segment is not a protein coding region, which can accumulate more mutations without affecting function.
d. D-loop region, because this protein coding region can accumulate more mutations and affect function.
e. D-loop region, because this non-coding region can accumulate more mutations without affecting function.

c. HVS I (Hyper Variable Segment I), because this segment is not a protein coding region, which can accumulate more mutations without affecting function.

In the DNA extraction procedure, chelex was added to the sample of your cheek cells. What was the reason for its addition and what mechanism was used to disrupt the cell walls of your cheek cells?

Select one:
a. Chelex has a very high affinity for DNA and hence helps in DNA extraction.
b. Chelex binds to RNA and proteins leaving behind DNA for extraction. The Sample was vortexed to disrupt the cell membrane.
c. Chelex binds to DNase the enzyme that degrades DNA causing a conformational change making DNase inactive. The sample was vortexed in order to disrupt the cell membrane.
d. Chelex is a powerful detergent and was used to disrupt the cell membrane.
e. Chelex binds to Magnesium, a cofactor needed for DNase, an enzyme that degrades DNA. The sample was heated to disrupt the cell membrane.

e. Chelex binds to Magnesium, a cofactor needed for DNase, an enzyme that degrades DNA. The sample was heated to disrupt the cell membrane.

The DNA polymerase used in the PCR method has what unique feature that makes its use superior to the DNA polymerase found in the human cells, for in vitro DNA synthesis?

Select one:
a. The PCR DNA polymerase has a higher denaturing temperature compared to the DNA polymerase in human cells.
b. It can synthesize both strands at the same time
c. It doesn't require a primer
d. It binds to DNA with a higher affinity
e. It has the ability to replicate itself

a. The PCR DNA polymerase has a higher denaturing temperature compared to the DNA polymerase in human cells.

Which of the following is NOT required for DNA amplification?

Select one:
a. Sequencing primer.
b. A reverse and forward primer.
c. Buffer Solution.
d. DNA bases.
e. Taq Polymerase.

a. Sequencing primer.

Which of these rules for designing a primer pair is incorrect?

Select one:
a. Primers that are too long will have difficulty binding fully to the DNA, and primers that are too short will not bind to the DNA with enough specificity.
b. Primers should not have long runs of the same base in a row, because this can lead to mispriming.
c. Primers should end their 3' ends with A or T, or AT, or TA.
d. Primers should consist of about 40% A-T pairs and 60% G-C pairs.
e. Primers should have similar melting temperatures to each other and to the temperature at which double-stranded DNA dissociates into single strands.

c. Primers should end their 3' ends with A or T, or AT, or TA.

In what order do the three main steps in each cycle of PCR occur?

Select one:
a. denaturation, extension, annealing
b. denaturation, annealing, extension
c. annealing, denaturation, extension
d. extension, denaturation, annealing
e. extension, annealing, denaturation

b. denaturation, annealing, extension

When designing primers for use in PCR, which of the following base pair compositions is considered the best?

Select one:
a. Adenine and Cytosine should make up 10 - 20% of the total base pairs.
b. Guanine and Cytosine should make up 50 - 60% of the total base pairs.
c. Adenine and Thymine should make up 50 - 60% of the total base pairs.
d. Guanine and Cytosine should make up 30 - 40% of the total base pairs.
e. Guanine and Thymine should make up 30 - 40% of the total base pairs.

b. Guanine and Cytosine should make up 50 - 60% of the total base pairs.

In mitochondrial DNA isolation lab, if the DNA is susceptible to DNases, what is the best solution to prevent this problem?

Select one:
a. putting solution on the heat bath as higher temperature renders DNase non-functional
b. add chelex; because it binds to the DNase, making the DNase not functional
c. add chelex; because it binds to Mg2+ in the extract
d. centrifuge the solution to separate the DNase and the DNA into separate layers
e. vortex the solution to separate the DNase and the DNA into separate layers

c. add chelex; because it binds to Mg2+ in the extract

In the DNA Isolation and Amplification lab, we must amplify a region of mitochondrial DNA by using a technique called Polymerase Chain Reaction (PCR) ________.

Select one:
a. because we need many copies to sequence the DNA
b. for DNA reproduction
c. to increase the efficiency of Taq polymerase
d. to increase the frequency of Mg2+ binding
e. because this makes it is easier for primers to bind

a. because we need many copies to sequence the DNA

What is the technique used for DNA amplification?

Select one:
a. BLAST
b. None of these
c. Gel Electrophoresis
d. Polymerase Chain Reaction
e. PRIMER 3

d. Polymerase Chain Reaction

The function of the Chelex beads in the DNA Isolation and Amplification lab is to

Select one:
a. prevent DNA degradation by binding to Mg2+
b. prevent DNA degradation by releasing DNases
c. prevent DNA degradation by binding to DNases
d. allow the DNA to form a pellet
e. prevent DNA degradation by releasing Mg2+

a. prevent DNA degradation by binding to Mg2+

In one step of PCR the temperature is lowered to about 50-60C, what is the point of this?

a. because it is the optimum temperature for Taq Polymerase
b. to add a sequencing primer
c. to separate the DNA strands
d. to prevent DNA degradation
e. allows the hybridization of the primers

e. allows the hybridization of the primers

What is the special property of Taq polymerase that allows it to work in a PCR reaction?

a. taq polymerase is cheaper than others
b. there is noting special its just like all the other polymerases
c. it is heat resistant
d. it is bigger than other polymerases
e. it is non degrading

c. it is heat resistant

Which of the following is true about mitochondrial DNA?

Select one:
a. Mitochondrial DNA is linear like nuclear DNA.
b. There are fewer copies of mitochondrial DNA than copies of nuclear DNA in a cell.
c. The mother and father contribute equally to the mitochondrial genome.
d. Mitochondrial DNA is a double helix like nuclear DNA.

d. Mitochondrial DNA is a double helix like nuclear DNA.

Why is Mitochondrial DNA only used to trace maternal lineage?

Select one:
a. Because maternal mitochondrial DNA is more abundant than paternal mitochondrial DNA.
b. Because sperms do not contain mitochondria.
c. Because paternal mitochondrial DNA is the same for everybody.
d. Because the sperm did not contribute its mitochondria upon fertilization.

d. Because the sperm did not contribute its mitochondria upon fertilization.

What is the purpose of adding dNTPs to the PCR set up?

Select one:
a. The dichromate in dNTPs allows for visualization of the DNA.
b. They inhibit Taq polymerase from forming DNA copies outside the desired region.
c. They provide a suitable chemical environment for the stability of DNA Polymerase.
d. They act as the building blocks from which DNA polymerase can synthesize new strands.
e. They anneal at low temperatures

d. They act as the building blocks from which DNA polymerase can synthesize new strands.

When designing a primer, the primer length is ideally between _____ and _____ base pairs long.

Select one:
a. 40 and 50
b. 20 and 30
c. 0 and 10
d. 10 and 20
e. 50 and 100

b. 20 and 30

All of the following are true regarding the DNA isolation and amplification lab except:

Select one:
a. The sequencing primer is specific to a region that needs to be amplified.
b. We looked at a protein-coding region that can collect many mutations without losing function.
c. Mitochondrial DNA is inherited just from the mother because the mitochondria in the sperm is destroyed after fertilization.
d. Taq Polymerase is used in PCR because it is heat resistant and can resist degradation.
e. Chelex prevents DNA degradation by binding all of the Mg2+.

b. We looked at a protein-coding region that can collect many mutations without losing function.

Which one of the following statement should not be in the set of rules for primer design?

Select one:
a. Melting temperatures should be between 55-80 C.
b. Guanine and cytosine should make up 50-60% of the total base pairs.
c. Primers should between 20-30 base pairs long.
d. Primers should contain long runs (four or more of the same base in a row).
e. Primers should end (3') in a G or C, or CG or GC.

d. Primers should contain long runs (four or more of the same base in a row).

What characteristic(s) distinguishes mitochondrial DNA from nuclear DNA?

Select one:
a. Mitochondrial DNA is inherited strictly from the mother.
b. Mitochondrial DNA contains both the control region and protein coding region.
c. Mitochondrial DNA encodes proteins, tRNAs and rRNAs.
d. Mitochondrial DNA sequences are termed diplotypes.

a. Mitochondrial DNA is inherited strictly from the mother.

What is the purpose of using Chelex beads during DNA isolation for PCR?

Select one:
a. Chelex bind all Magnesium ion to prevent its interaction with DNAses, which use Magnesium as a cofactor.
b. Chelex helps mark the DNA so it is easily recognized by the PCR primers.
c. Chelex isolate DNA by disrupting cell walls by interacting with the DNAses.
d. Chelex help degrade the DNA by interacting with the Mg 2+ in the cell walls.

a. Chelex bind all Magnesium ion to prevent its interaction with DNAses, which use Magnesium as a cofactor.

Lab F

Agarose and Polyacrylamide Gels

Which of the following would NOT be determined by comparing two PCR samples after agarose gel electrophoresis?

Select one:
a. Differences in primer effectiveness.
b. Differences in DNA concentration.
c. Differences in DNA sizes.
d. Differences in DNA sequence.

d. Differences in DNA sequence.

If a protein is able to migrate down a gel matrix without first being treated with SDS, what is true of this protein?

Select one:
a. The protein has neither an inherently positive nor inherently negative net charge.
b. The protein has several subunits.
c. The protein has an inherently positive net charge.
d. The protein has an inherently negative net charge.
e. The protein has only one subunit.

d. The protein has an inherently negative net charge.

What is the function of sodium dodecyl sulfate in SDS-Page?

Select one:
a. To disrupt the noncovalent interaction between subunits of proteins, then adding an overall positive charge to the protein in proportion to its length
b. To add a fluorescent tag that illuminates the protein subunits allowing them to become visible under UV light
c. To indicate the number of subunits of the protein
d. To disrupt the noncovalent interaction between subunits of proteins, then adding an overall negative charge to the protein in proportion to its length
e. To break disulfide linkages of the protein

d. To disrupt the noncovalent interaction between subunits of proteins, then adding an overall negative charge to the protein in proportion to its length

A student performs SDS-PAGE on a 160 kD protein composed of two 30 kD and two 50 kD subunits. Assuming all four subunits are connected by disulfide bonds, which of the following would not occur if the student forgets to add the reducing agent?

Select one:
a. a uniform charge to mass ratio
b. unfolding of peptide chains
c. disruption of noncovalent interactions
d. multiple bands in his lane
e. smaller molecules migrating farther than larger molecules

d. multiple bands in his lane

The reducing agent, b-mercaptoethanol, in SDS-PAGE

Select one:
a. oxidizes disulfide bonds which dissociates protein subunits.
b. intercalates into proteins making them visible under UV light.
c. reduces disulfide bonds which denatures the protein.
d. makes disulfide linkages visible under UV light.
e. enzymatically cleaves disulfide linkages.

c. reduces disulfide bonds which denatures the protein.

The farther a DNA molecule migrates during electrophoresis

Select one:
a. the smaller the molecule.
b. the larger the molecule.
c. the smaller its charge:mass ratio.
d. the bulkier the shape of the DNA is.
e. the greater its positive charge.

a. the smaller the molecule.

After running an SDS-PAGE gel you find 2 bands. The first band is 20kD in size and the second is 50kD. You know your protein mass is 140kD.How many subunits of each protein type do you have?

Select one:
a. 7 Subunits of 20kD
b. 2 Subunits of 50kD and 3 Subunits of 20kD
c. 3 Subunits of 50kD and 3 Subunits of 20kD
d. 3 Subunits of 50kD and 2 Subunits of 20kD
e. 2 Subunits of 50kD and 2 Subunits of 20kD

e. 2 Subunits of 50kD and 2 Subunits of 20kD

Nucleic acid absorbs light mostly at ____, where each absorbance unit is equal to ____ of DNA.

Select one:
a. 260nm, 50 mg/ml
b. 280nm, 0.050 mg/ml
c. 260nm, 0.050 mg/ml
d. 280nm, 50 µg/ml
e. 240nm, 50 µg/ml

c. 260nm, 0.050 mg/ml

SDS-PAGE and agarose gel are two options in which proteins and DNA can be separated and analyzed. There are many differences and similarities between the two methods. Which of the following is NOT one of these similarities or differences?

Select one:
a. SDS is required when running protein samples with electrophoresis, since proteins need to be coated with a uniform, negative charge.
b. Agarose gel has a lower resolution than a SDS-PAGE gel.
c. Agarose is safe to handle as is, whereas acrylamide is safe to handle only after polymerization.
d. In both gels, the samples run toward the positive electrode, since they are negatively charged.
e. SDS-PAGE gels can only be used to run protein samples. Agarose gels can be used to run both protein and DNA samples.

e. SDS-PAGE gels can only be used to run protein samples. Agarose gels can be used to run both protein and DNA samples.

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?

Select one:
a. Run a SDS-PAGE with coomasie blue and b-mercaptoethanol followed by X-ray crystallography
b. Run a SDS-PAGE after mixing the protein with coomassie blue and perform a Western Blot
c. Perform gel filtration and run a SDS-PAGE after mixing the protein with b-mercaptoethanol
d. Run a PAGE after denaturing the protein in SDS and perform ultracentrifugation through a glucose gradient using flourescein isothiocyanate (FITC)
e. 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

c. Perform gel filtration and run a SDS-PAGE after mixing the protein with b-mercaptoethanol

If an SDS-PAGE gel photograph shows protein subunit bands at 40kD and 60kD, and you know that the total weight of your unknown protein is 240kD, you know that you would have ____ of the 40kD subunit and ____ of the 60kD subunit. From this, you also know that your unknown protein is a __________.

Select one:
a. 3; 2; tetramer
b. 3; 2; pentamer
c. 4; 1; monomer
d. 3; 2; homodimer
e. 2; 3; dimer

b. 3; 2; pentamer

Gel filtration provides an _______ of the molecular weight of the protein in its _______ state.

Select one:
a. estimated value, native
b. estimated value, disrupted
c. exact value, disrupted
d. exact value, charged
e. exact value, native

a. estimated value, native

You are in the lab trying to identify Protein X. The first gel you run for Protein X gives you one band at 30 kD and another band at 75 kD. You run another gel for Protein X using another technique. This time, you get one band at 210 kD. Circle below the possible techniques you used to obtain the above results.

Select one:
a. SDS alone in both
b. SDS plus reducing agent in the first gel & SDS alone in the second gel
c. SDS plus reducing agent in both
d. SDS alone in the first gel & SDS plus reducing agent in the second gel
e. Gel Filtration in the first gel & and SDS alone in the second gel

b. SDS plus reducing agent in the first gel & SDS alone in the second gel