Bio Lab Final
EXPERIMENT 2: Which diffusion bag caused the most rapid change in pH when added to its beaker?
the diffusion bag containing 10% acetic acid
Whose sample had the approximately 990 bp and 470 bp sized DNA fragments?
The Child
What was the size of your amplified DNA sample fragment
1.5 kbp
EXPERIMENT 4: Based on your results, which of the solutions that you tested contained proteins?
35% egg albumin solution
Which of the following is NOT a component of DNA?
Amino Acid
EXPERIMENT 3: Based on your results, which of the solutions that you tested with Sudan III solution contained lipids?
Corn Oil
Why is the structure of DNA called a double helix?
DNA is made of two strands of nucleotides wound together in a spiral
CONCLUSIONS: Why can Benedict's solution be used to distinguish between glucose and sucrose?
Glucose is a reducing sugar, and sucrose is not a reducing sugar.
EXPERIMENT 1: Based on your results with iodine and starch, what material(s) diffused across the membrane?
Iodine
EXPERIMENT 1: What happened to the iodine in the diffusion bag?
It diffused out of the diffusion bag and into the beaker.
EXPERIMENT 1: What color changes did you observe when you added Benedict's solution to water and heated it?
It turned from colorless to blue after the addition of the Benedict's solution, but stayed blue after it was heated.
EXPERIMENT 3: What color changes did you observe when you added Sudan III solution to corn oil?
It turned from yellow to having a thick, bright red layer on top of a colorless layer.
CONCLUSIONS: Which of the following correctly describes the relationship between monosaccharides and starches?
Monosaccharides are the building blocks from which starches are made.
CONCLUSIONS: Is diffusion the only way materials can enter a cell?
No, a cell is capable of actively transporting materials across its membrane.
CONCLUSIONS: You have identified a new form of life from the exoplanet Kepler-452b. The membrane of this cell is interesting because it is impermeable to water, but proteins of all sizes can pass through unrestricted. The concentration of protein within the cell is 5 mg/mL. You place the cell in a solution that contains water and 2.5 mg/mL protein. Predict what happens to the cell.
Protein will move out of the cell to equalize its concentration.
EXPERIMENT 3: How did the mass of the beaker change after incubating for 1 minute with the diffusion bag containing water?
The beaker gained mass.
Which of the following is NOT one of the steps of the PCR process
The sample is cooled to about 10 C to deactivate the DNA polymerase until the next step is ready
EXPERIMENT 1: What was the color of the starch solution in the beaker after dialysis?
The starch solution turned bluish black after dialysis.
EXPERIMENT 3: What color was the liquid in the test tubes when the biuret solution was added?
blue
EXPERIMENT 1: What color did the liquid in the beaker turn upon adding the diffusion bag to the beaker?
blueish Black
CONCLUSIONS: Which of the following is an image of iodine solution and 2% starch solution?
deep blue
EXPERIMENT 1: Based on your results, which of the solution(s) that you tested with Benedict's solution contained reducing sugars?
glucose solution
EXPERIMENT 5: Which biological molecules were present in the whole milk?
lipids, reducing sugars, and proteins
CONCLUSIONS: The rate of diffusion is affected by which of the following:
molecular weight
EXPERIMENT 5: Which food(s) had starches and protein?
potato juice
EXPERIMENT 5: Which biological molecules were present in the onion juice?
proteins and reducing sugars
EXPERIMENT 1: What is indicated by Benedict's solution changing from blue to orange when heated?
the presence of reducing sugars
CONCLUSIONS: What is iodine solution changing from reddish brown to bluish black an indication of?
the presence of starches or complex carbohydrates
EXPERIMENT 2: What was the change in mass for the beaker in which the diffusion bag initially contained 15% fructooligosaccharides solution? mfinal−minitial=Δm Positive values will reflect a gain of mass. Negative values will reflect a loss of mass. Note that depending on how exact you were, there is a range of possible answers. Pick the answer that is closest to yours.
-1.744 g
EXPERIMENT 2: What was the change in mass for the diffusion bag when the bag initially contained 5% fructooligosaccharides solution? mfinal−minitial=Δm Positive values will reflect a gain of mass. Negative values will reflect a loss of mass. Note that depending on how exact you were there is a range of possible answers. Pick the answer that is closest to yours.
-1.826 g
EXPERIMENT 2: What was the change in mass for the beaker in which the diffusion bag initially contained 10% fructooligosaccharides solution? mfinal−minitial=Δm Positive values will reflect a gain of mass. Negative values will reflect a loss of mass. Note that depending on how exact you were there is a range of possible answers. Pick the answer that is closest to yours.
0.000 g
EXPERIMENT 4: What was the final concentration of fructooligosaccharides in the beakers?
10%
EXPERIMENT 2: Which of the solutions that you tested with iodine solution had positive results?
2% starch solution
EXPERIMENT 2: Which of the solutions that you tested with iodine solution turned bluish black?
2% starch solution
How far did the 3 kbp band of the DNA ladder travel on your gel? the distances will vary a little depending on how long you ran the gel, so pick the distance closest to the one you measured
25 mm
EXPERIMENT 2: What was the change in mass for the diffusion bag when the bag initially contained 20% fructooligosaccharides solution? mfinal−minitial=Δm Positive values will reflect a gain of mass. Negative values will reflect a loss of mass. Note that depending on how exact you were, there is a range of possible answers. Pick the answer that is closest to yours.
3.441 g
EXPERIMENT 4: What was the initial mass of each of the four beakers containing water and fructooligosaccharides used in this experiment? Choose the closest answer.
310.000 grams
Which of the following are the approximate sizes of the DNA fragments for the mother?
990 bp and 240 bp
Which method is used to remove DNA from a cell?
Extraction
EXPERIMENT 1: What color changes did you observe when you added Benedict's solution to the 5% glucose solution and heated it?
It turned from colorless to blue after the addition of the Benedict's, but it turned red after it was heated
EXPERIMENT 3: What color changes did you observe when you added Sudan III solution to water?
It turned light brownish red
CONCLUSIONS: Why can Benedict's solution not be used to distinguish between glucose and lactose, which is a disaccharide with a reducing carbonyl group?
Lactose and glucose are both reducing sugars. Benedict's solution distinguishes between reducing and nonreducing sugars
EXPERIMENT 4: Which of the following is an image of biuret solution and 35% egg albumin solution?
Purple
Suppose you want to insert your PCR product into another organism's DNA. which DNA technique would you use
Recombinant DNA
Forensic scientists are trying to find an exact DNA match to a sample left at the scene of a crime. The sample from the crime scene has both a 900 bp and a 260 bp DNA fragment. Based on the suspects' profiles below, which one likely committed the crime? Suspect I has 900 bp and 540 bp sized DNA fragments Suspect II has 840 bp and 260 bp sized DNA fragments Suspect III has 900 bp and 260 bp sized DNA fragments Suspect IV has 730 bp and 380 bp sized DNA fragments
Suspect III
CONCLUSIONS: What results would you expect from a biuret test of chicken soup?
The biuret solution will change to purple.
EXPERIMENT 3: What was the appearance of the Elodea cells in hypertonic solution?
The cell membrane shriveled and pulled away from the cell wall.
EXPERIMENT 3: What was the appearance of the Elodea cells in aquarium water?
The cell membrane was pressed against the cell wall
EXPERIMENT 3: What was the appearance of the Elodea cells in hypotonic solution?
The cell membrane was pressed against the cell wall, and the cell was almost bursting.
EXPERIMENT 2: When the diffusion bag contained 20% or 15% fructooligosaccharides, the net movement of water was from the beaker to the bag. However, the change in mass was greater when the dialysis bag contained 20% fructooligosaccharides than when it contained 15% fructooligosaccharides. Why?
The concentration of fructooligosaccharides in the 20% solution was higher than in the 15% solution, so more water needed to move from the beaker to the bag to equalize the concentration.
CONCLUSIONS: Based on your results in Experiment 3, why do the vegetables in dressed salads wilt over time?
The dressing is a hypertonic solution because it has salt, sugar, or other spices dissolved in an aqueous base. Plasmolysis in the cells of the vegetables causes the vegetable as a whole to wilt.
EXPERIMENT 3: After the 1 minute incubation, you removed the diffusion bag from the beaker. You tested the solution in the beaker and the solution in the diffusion bag using the biuret test. What would a positive biuret test for the solution in the beaker, but not for the diffusion bag, indicate had happened?
The egg albumin remained in the beaker
How are DNA fragments separated on an agarose gel during electrophoresis?
The electric current makes the fragments migrate through the gel. The smaller fragments migrate through the gel the fastest.
EXPERIMENT 2: Water was able to move across the dialysis membrane but the fructooligosaccharide molecules were not. Explain why this is the case.
The fructooligosaccharide molecules are larger than water molecules, and will not fit through the pores in the dialysis membrane.
Suppose your gel had looked like the following image after you ran your experiment. What most likely happened to create this result?
The gel was not run long enough.
Suppose you found the gel analysis results below during your experiment. if these were your results, what error likely occurred in your experiment
The gel was run for too long some ladder and PCR fragments ran off the gel
EXPERIMENT 3: What caused the changes you observed between the slides of Elodea in aquarium water and Elodea in hypertonic solution?
The hypertonic solution caused water to leave the cell. This shrunk the cytoplasm and pulled the cell membrane away from the cell walls, a condition called plasmolysis.
EXPERIMENT 1: What was the color of the iodine solution in the diffusion bag before and after dialysis?
The iodine solution was reddish brown before dialysis and did not change color during dialysis
EXPERIMENT 1: Why was iodine able to diffuse across the membrane whereas starch was not?
The pores of the bag are larger than the iodine molecules but smaller than the starch molecules.
Suppose you found the gel analysis results below during your experiment. if these were your results, what error likely occurred in your PCR reaction?
The positive control failed. the band for the PCR reaction cannot be trusted
EXPERIMENT 2: Explain the results of the experiment in which the diffusion bag contained 5% fructooligosaccharides.
The sugar concentration was higher in the beaker than in the bag, so water moved from the bag to the beaker.
EXPERIMENT 2: Explain the results of the experiment in which the diffusion bag contained 15% fructooligosaccharides.
The sugar concentration was lower in the beaker than in the bag, so water moved from the beaker to the bag
EXPERIMENT 2: Explain the results of the experiment in which the diffusion bag contained 20% fructooligosaccharides.
The sugar concentration was lower in the beaker than in the bag, so water moved from the beaker to the bag
EXPERIMENT 2: Explain the results of the experiment in which the diffusion bag contained 10% fructooligosaccharides.
The sugar concentration was the same in the beaker and the bag, so there was no net movement of water
EXPERIMENT 4: Why did incubation of the diffusion bag containing a higher percentage of fructooligosaccharides than was in the beaker decrease the mass of liquid in the beaker?
Water moved into the diffusion bag from the beaker to equalize the concentration of fructooligosaccharides on either side of the membrane.
CONCLUSIONS: Suppose you are given a diffusion bag filled with a protein whose mass is 30,000 g/mol. The MWCO of the diffusion bag is 25,000 g/mol. The concentration of the protein within the diffusion bag is 1 M. You place the diffusion bag into a beaker containing only water. Predict what will take place next
Water will move into the diffusion bag from the beaker, because the diffusion bag will not let the protein pass.
EXPERIMENT 5: After completing the experiment with Benedict's solution, what color was your potato juice sample?
Yellow
Which alleged father has a DNA fragment that matches the size of one of the child's DNA fragments and is, therefore, likely the child's father? You must confirm that this DNA fragment is NOT present in the mother's DNA, because only then can you say definitively that this DNA fragment came from her father.
alleged father #2
John Doe has two possible fathers. The DNA fragment sizes of John Doe, John Doe's mother, and two possible fathers are as follows: John Doe's mother - 850 bp and 400 bp John Doe - 680 bp and 400 bp Possible father I - 680 bp and 500 bp Possible father II - 680 bp and 280 bp Which, if either, of the two men could be John Doe's father and why?
both of the two men, because they and John Doe all have a 680 bp sized DNA fragment
CONCLUSIONS: Suppose Benedict's solution was added to white grape juice and heated. The color changed from blue to orange. Based on this result, which biological molecules are present in the white grape juice?
reducing sugars
EXPERIMENT 5: Which food(s) tested positive for proteins?
skim milk, whole milk, onions, and potatoes
CONCLUSIONS: Suppose iodine solution was added to a chocolate chip cookie solution and the color changed to bluish black. Based on this result, what biological molecules are present in the chocolate chip cookie solution?
starches
EXPERIMENT 4: Incubation of which diffusion bag caused no change in the mass of liquid in the beaker?
the diffusion bag containing 10% fructooligosaccharides