Molecular Biology

Question 1

The polymerase chain reaction (PCR) involves three processes. Select the order in which these occur

a. Extension → Annealing → Denaturation
b. Annealing → Denaturation → Extension
c. Denaturation → Annealing → Extension
d. Denaturation → Extension → Annealing

Answer 1

c. Denaturation → Annealing → Extension

Question 2

In the PCR cycle, how is denaturation accomplished?

a. Heat
b. Alkali treatment
c. Addition of sulfonylurea
d. Formamide

Answer 2

a. Heat

Question 3

What is the unique characteristic of the DNA polymerase, Taq DNA polymerase, used in PCR?

a. It can be enzyme labeled
b. It is more efficient than eukaryotic polymerases
c. It is heat stable
d. It works with DNA of any species

Answer 3

c. It is heat stable

Question 4

In PCR testing, the initial step involves adding the DNA in question to a mixture of taq polymerase, excess nucleotides, MgCl2, and primers. This mixture is placed in which of the following instruments to allow the amplification to take place?

a. Flow cytometer
b. Capillary array sequencer
c. Thermal cycler
d. Electrophoresis chamber

Answer 4

c. Thermal cycler

Question 5

A physical agent used in fixation is:

a. Stabilization of proteins
b. Heat
c. Coagulation
d. Alcohol

Answer 5

b. Heat

Question 6

To prevent the formation of formalin pigment in tissues, formalin should be:

a. Heated
b. Cooled
c. Buffered
d. Acidified

Answer 6

c. Buffered