Question

12. To see if your polymerase chain reaction was successful and it amplified the right sequence of interest, you electrophorese the products from the reaction on an agarose gel. After staining the gel you find there are two bands of different sizes. Which one of the following is a possible explanation for these results? (1 point)

a. The PCR induced a frame shift mutation into the DNA sequence.

b. RNA polymerase copied the DNA into two copies of RNA.
c. The primers annealed to two different templates.
d. a and b.

  

13. If a gene is inserted into an antibiotic resistance gene on a plasmid, resulting clone will be_______________ to the antibiotic (1 point).
a. resistant
b. sensitive

c. partially resistant

d. partially sensitive

15. Which of the following is used to detect cells that are expressing your receptor of interest? (1 point)

1. FACS can be used to identify only the cells that do not express the receptor.

2. a radiolabeled or fluorescently labeled antibody specific for the cell

3. a radiolabeled or fluorescently labeled receptor specific for the receptor

4. a radiolabeled or fluorescently labeled ligand specific for the receptor

5. only PCR can detect your receptor of interest

16. Which of the following is an effective way to obtain cDNA encoding of a desired receptor protein? (1 point)

1. plasmid cDNA library preparation

2. SDS-PAGE/Western blotting

3. PCR

4. expression cloning

5. DNA electrophoresis

Answer 1

12) In the PCR two sized bands are obtained from a single reaction, this can be due the primer binding to different sites on different templates.

that is the same set of primers can amplify a large region that produces a large band, and these primers are complementary to the DNA such that DNA polymerase can amplify a smaller region which results in small band, so two different sized bands can be obtained.

PCR uses DNA polymerase and not RNA polymerase,

Frameshift mutations are due to the insertion or deletion of nucleotides which are not in the multiples of three, this changes the amino acid sequence from the point of mutation so the answer is

c) The primers annealed to two different templates.

13) insertion of gene to the antibiotic resistance gene will become non-functional so the resulting clone cannot grow int he presence of anitbiotic that is it becomes sensitive to the antibiotic so the answer is b) sensitive.