BIO Lab Gel Electrophoresis Visualize and separate nucleic acids Quiz

Question 1: What is the function of a ladder in gel electrophoresis?

a. Gauge the size of the bands in the sample

b. Negative control

c. Positive control

d. Prevent the bands from running off the gel

a. Gauge the size of the bands in the sample

Question 2: Where on the gel will the largest DNA molecules be, and why?

a. Near the top because they can not migrate through the matrix of the gel as fast

b. Near the top because they are less negatively charged

c. Near the bottom because the migrate through the matrix of the gel faster

d. Near the bottom because they carry more negative charge

a. Near the top because they can not migrate through the matrix of the gel as fast

Question 3: How are DNA or RNA molecules visualized on the gel?

a. A labeled dye that binds to the DNA is added

b. The negative charge of the DNA is used to detect the bands

c. The bands cast a shadow when light passes through the gel

d. The DNA is extracted from the gel and then measured

a. A labeled dye that binds to the DNA is added

Question 4: When running a gel electrophoresis experiment, what property of DNA allows the molecules to migrate from one end of the gel apparatus to the other end?

a. DNA is negatively charged, so it moves toward the positively charged end

b. DNA is water soluble, so it diffuses through the gel automatically.

c. DNA can be denatured by high temperatures, so it moves from the warm end to the cool end.

d. DNA is pulled to the end of the gel using vacuum force.

a. DNA is negatively charged, so it moves toward the positively charged end

Question 5: After the gel is run, where will the largest DNA fragments be located, and why?

a. near the top of the gel because they do not migrate through the gel as quickly as smaller fragments

b. near the top of the gel because they migrate through the gel faster than the smaller fragments

c. near the bottom of the gel because they migrate through the gel faster than the smaller fragments

d. near the bottom of the gel because they carry a more negative charge than smaller fragments

a. near the top of the gel because they do not migrate through the gel as quickly as smaller fragments

Question 6: Electrophoresis is a technique to separate charged macromolecules based on their__________, using an electric current.

a. Size

b. Charge

c. Color

d. Density

a. Size

Question 7: Why do we need loading buffer to do Gel Electrophoresis?

a. Loading buffer contains a color reagent to help visualize how far the DNA has traveled during gel electrophoresis.

b. DNA is water soluble, so it diffuses through the buffer automatically.

c. DNA can be denatured by high temperatures, so buffer reduces the temperature.

a. Loading buffer contains a color reagent to help visualize how far the DNA has traveled during gel electrophoresis.

Question 8: Smaller DNA molecules move ____________through the gel than larger DNA molecules, leading to size separation.

a. Faster

b. Slower

a. Faster

Question 9: After electrophoresis, DNA is visualized and appears as _______________ of grouped DNA fragments of the same length.

a. Dotted line

b. graph

c. Bands

c. Bands

Question 10: The sizes of the nucleic acid samples can be estimated by comparing the distance with the molecular weight standard samples (also called DNA ladder).

a. True

b. False

a. True