BIOTECH BACE EXAMS EVALUATION UPDATED QUESTIONS
AND ANSWERS GRADED A+
✔✔Lipids - ✔✔Example: Hormones. Functions: Membrane structure, energy storage,
insulation.
✔✔Imagine you have been given a preparation of genomic DNA that contains a gene
that you would like to transfer into a plasmid. On either side of the gene is a restriction
site for the restriction enzyme EcoRI.
The genomic DNA has already been cut with the restriction enzyme HindIII, which does
not cut with in the gene of interest. The plasmid has a single restriction site for EcoRI,
but none for HindIII.
Which of the strategies below could be used for ligating the genomic DNA into the
EcoRI site in the plasmid? - ✔✔Cut the genomic DNA again with EcoRI and insert the
DNA fragment into the plasmid cut with EcoRI.
✔✔How many grams is 2.6kg? - ✔✔2600
✔✔Plasmid DNA is purified using anion exchange column chromatography. Why? -
✔✔Because DNA is negatively charged, binds to the positively charged resin, and is
eluted with increasing salt.
✔✔Following a restriction digest of plasmid DNA, you anticipate having of 4 DNA
fragments that are very close in size (between 700 and 1000 bp). Which of the following
will increase the chances for good separation on an agarose gel, so that you may
visualize both bands on the gel? - ✔✔Use a higher percentage of agarose (1.5 % or
higher) when making the gel
✔✔Which of the following will change the resistance of the electrophoresis unit being
run at a constant voltage? - ✔✔Amount of buffer,
Thickness of agarose gel and
Percentage of agarose in gel
✔✔Which of the following principle(s) result in DNA molecules being separated on an
agarose gel? - ✔✔DNA moves toward the positive electrode due to negative charge of
phosphate backbone and DNA fragments are separated in the gel matrix based on their
size
✔✔The negative electrode terminal is located: - ✔✔At the top of the gel (closest to
wells)
✔✔Staining with Coomassie Blue - ✔✔Visualizing proteins after PAGE
, ✔✔Adding loading dye to protein samples - ✔✔Visualizing samples for loading into
wells, and monitoring sample migration during PAGE
✔✔Adding a molecular weight (MW) standard to an empty well - ✔✔Determining the
relative sizes of the samples run during PAGE
✔✔Adding SDS to the sample buffer and the PAGE running buffer - ✔✔Coating the
sample proteins with an negative charge and denaturing them
✔✔To focus a specimen on a microscope, it is best to start with which objective? -
✔✔Low power
✔✔The difference in hydrogen ion concentration between a solution of pH 4.00 and a
solution of pH 6.00 is: - ✔✔100-fold
✔✔How does a buffer resist pH change upon the addition of an acidic or basic
components? - ✔✔It reacts with the excess H+ or OH- ions in the solution
✔✔Below is a DNA sequence that you are trying to amplify from a genomic DNA
sample. Evaluate the appropriateness of using the potential primer (below the DNA
strand) to amplify the specific sequence of DNA.
Sequence of interest: 3'-ACATGCTGCTGCTGGTCACAAGTCAATTCCTAA-5'
Potential primer to the sequence: 5'-TGTACGACGACGAC-3' - ✔✔This is a good primer
because it is anti-parallel and no long repeats.
✔✔Using the steps listed below, put them in order to best describe the sequence of
steps that occurs in a PCR cycle:
1. The primers hybridize to the target DNA.
2. The mixture is heated to a high temperature to denature the double stranded DNA.
3. DNA polymerase extends the primers to make a copy of the target DNA. - ✔✔2,1,3
✔✔Polymerase Chain Reaction (PCR) uses which enzyme to "amplify" DNA? - ✔✔DNA
polymerase
✔✔Genetic Engineering is: - ✔✔The alteration of an organism's genetic, or hereditary,
material and Used to produce recombinant proteins for therapeutic use
AND ANSWERS GRADED A+
✔✔Lipids - ✔✔Example: Hormones. Functions: Membrane structure, energy storage,
insulation.
✔✔Imagine you have been given a preparation of genomic DNA that contains a gene
that you would like to transfer into a plasmid. On either side of the gene is a restriction
site for the restriction enzyme EcoRI.
The genomic DNA has already been cut with the restriction enzyme HindIII, which does
not cut with in the gene of interest. The plasmid has a single restriction site for EcoRI,
but none for HindIII.
Which of the strategies below could be used for ligating the genomic DNA into the
EcoRI site in the plasmid? - ✔✔Cut the genomic DNA again with EcoRI and insert the
DNA fragment into the plasmid cut with EcoRI.
✔✔How many grams is 2.6kg? - ✔✔2600
✔✔Plasmid DNA is purified using anion exchange column chromatography. Why? -
✔✔Because DNA is negatively charged, binds to the positively charged resin, and is
eluted with increasing salt.
✔✔Following a restriction digest of plasmid DNA, you anticipate having of 4 DNA
fragments that are very close in size (between 700 and 1000 bp). Which of the following
will increase the chances for good separation on an agarose gel, so that you may
visualize both bands on the gel? - ✔✔Use a higher percentage of agarose (1.5 % or
higher) when making the gel
✔✔Which of the following will change the resistance of the electrophoresis unit being
run at a constant voltage? - ✔✔Amount of buffer,
Thickness of agarose gel and
Percentage of agarose in gel
✔✔Which of the following principle(s) result in DNA molecules being separated on an
agarose gel? - ✔✔DNA moves toward the positive electrode due to negative charge of
phosphate backbone and DNA fragments are separated in the gel matrix based on their
size
✔✔The negative electrode terminal is located: - ✔✔At the top of the gel (closest to
wells)
✔✔Staining with Coomassie Blue - ✔✔Visualizing proteins after PAGE
, ✔✔Adding loading dye to protein samples - ✔✔Visualizing samples for loading into
wells, and monitoring sample migration during PAGE
✔✔Adding a molecular weight (MW) standard to an empty well - ✔✔Determining the
relative sizes of the samples run during PAGE
✔✔Adding SDS to the sample buffer and the PAGE running buffer - ✔✔Coating the
sample proteins with an negative charge and denaturing them
✔✔To focus a specimen on a microscope, it is best to start with which objective? -
✔✔Low power
✔✔The difference in hydrogen ion concentration between a solution of pH 4.00 and a
solution of pH 6.00 is: - ✔✔100-fold
✔✔How does a buffer resist pH change upon the addition of an acidic or basic
components? - ✔✔It reacts with the excess H+ or OH- ions in the solution
✔✔Below is a DNA sequence that you are trying to amplify from a genomic DNA
sample. Evaluate the appropriateness of using the potential primer (below the DNA
strand) to amplify the specific sequence of DNA.
Sequence of interest: 3'-ACATGCTGCTGCTGGTCACAAGTCAATTCCTAA-5'
Potential primer to the sequence: 5'-TGTACGACGACGAC-3' - ✔✔This is a good primer
because it is anti-parallel and no long repeats.
✔✔Using the steps listed below, put them in order to best describe the sequence of
steps that occurs in a PCR cycle:
1. The primers hybridize to the target DNA.
2. The mixture is heated to a high temperature to denature the double stranded DNA.
3. DNA polymerase extends the primers to make a copy of the target DNA. - ✔✔2,1,3
✔✔Polymerase Chain Reaction (PCR) uses which enzyme to "amplify" DNA? - ✔✔DNA
polymerase
✔✔Genetic Engineering is: - ✔✔The alteration of an organism's genetic, or hereditary,
material and Used to produce recombinant proteins for therapeutic use
