Polymerase Chain Reaction Lab Review

What is electrophoresis?

A method of sorting of molecules

Primer bonding to matching DNA sequence is a prerequisite to:

DNA polymerase

STR analysis

Different length may found in each individual. Since individuals might have different numbers of repeats creating their own specific DNA profiles.

DNA consists of positively charged molecules. True or False?

False

DNA flows to the anode. True or False?

True

DNA polymearse is

a synthesizing enzyme

What is the template of the PCR reaction? a) DNA b) RNA c) Nucleotides d) Proteins

a) DNA

We are going to use the blood sample you collected at the crime scene. What needs to happen before the blood sample can be used for PCR? a) DNA has to be isolated from the cells b) No action is needed c) You should shake the tube d) The blood has to be frozen.

a) DNA has to be isolated from the cells

For which enzyme are nucleotides the substrate? a) DNA polymerase b) Ligase c) Protease d) Ribosome

a) DNA polymerase

Why is the Taq-polymerase special compared to most other polymerases? a) It can resist high temperatures b) It unfolds DNA c) It synthesizes DNA d) It can resist low temperatures

a) It can resist high temperatures

What happens to the probability of a 100% match between two different individuals when using 13 sets of primers for the DNA profile instead of one? a) It decreases b) It results in a match c) It increases d) It is not affected

a) It decreases

What are the building blocks of new copies of DNA? a) Nucleotides b) Primers c) Polymerase d) Amino acids

a) Nucleotides

What is the purpose of PCR? a) To copy and then make many copies of a specific region of DNA b) To reveal the sequence of a piece of DNA c) To copy the entire human genome d) To make just a few copies of DNA

a) To copy and then make many copies of a specific region of DNA

Primers are always designed to be complementary to the template DNA strand. Which of these sequences is the complementary sequence to the template sequence 5'-GTGGTCTGATCAACGGTAA-3'? a) 3'-GTGGTCTGATCAACGGTAA-5' b) 3'-CACCAGACTAGTTGCCATT-5' c) 5'-CACCAGACTAGTTGCCATT-3' d) 5'-GTGGTCTGATCAACGGTAA-3'

b) 3'-CACCAGACTAGTTGCCATT-5'

How does the DNA polymerase extend the primers into a new DNA strand? a) Adding nucleotides to the 3' and 5' ends of the primers b) Adding nucleotides to the 3' end of the primers c) Adding more primers to the strand d) Adding nucleotides to the 5' end of the primers

b) Adding nucleotides to the 3' end of the primers

The area where the primers bind marks which part of the PCR product? a) End b) Beginning C) Left side d) Right side

b) Beginning

What is the function of primers in a PCR reaction? a) Denature DNA b) Bind specific sites on the DNA c) Bind random sites on the DNA d) Copy DNA

b) Bind specific sites on the DNA

Which reagent acts as a template for the DNA polymerase so that knows which new DNA to make? a) Proteins the blood cells b) DNA from a blood sample c) Nucleotides d) Primers

b) DNA from a blood sample

At this step in the PCR process, (95°C) what happens to the DNA? a) It is kept intact b) It will be separated into two strands c) It will be twisted into double helix d) It will be broken into many pięces

b) It will be separated into two strands

What would happen no polymerase was added to the PCR reaction? a) 50% less DNA would be produced b) New DNA would not be generated c) New DNA would contain many errors d) The primers would anneal to the DNA

b) New DNA would not be generated

How is the DNA separated into single strands? a) The DNA polymerase separating the two DNA strands b) The high temperature (95 °C) c) The primers separating the two DNA strands d) The low temperature (54 °C)

b) The high temperature (95 °C)

So, who is the murderer? a) The PhD student b) The rival scientist c) The postdoc d) Not sure yet, I need more time to analyze the results.

b) The rival scientist

Why is it important to change the pipette tip? a) To employ more garbage men b) To avoid cross contamination c) To keep the lab bench clean d) To keep the lab assistant happy

b) To avoid cross contamination

DNA polymerase binds to the template DNA. In which direction is the new DNA subsequently synthesized? a) 3' 5' b) Random c) 5'3' d) 5' 3' and 3' → 5'

c) 5'3'

How many copies of DNA are required to see bands on the electrophoresis gel? a) 1000 copies b) 10 copies c) Millions of copies d) None

c) Millions of copies

What does a DNA polymerase do? a) Degrades proteins b) Unfolds DNA c) Synthesizes DNA d) Cleaves DNA

c) Synthesizes DNA

DNA is negatively charged. To which location in the electrophoresis gel does it migrate? a) The negative pole b) The corners c) The positive pole d) The sides

c) The positive pole

Why is a PCR cycle repeated 30 times? a) To make sure the PCR machine is working b) To avoid adding new reagents every cycle c) To get enough DNA d) To allow the polymerase to work

c) To get enough DNA

What can contamination of reagents leads to? a) Good results b) Reliable results c) Unreliable results d) Reproducible results

c) Unreliable results

How many sets of primers are needed for DNA profiling? a) 100 b) None c) 1 d) 13

d) 13 (at least 13 different regions are needed to reduce the probability of different people having the same DNA profiles)

Which word describes the charge of the DNA? a) Positively charged b) Not charged c) Highly charged d) Negatively charged

d) Negatively charged

What do you need to do each time before using pipette to collect liquid? a) Put on a used pipette tip b) Polish the pipette c) Shake the pipette d) Put on a new, sterile pipette tip

d) Put on a new, sterile pipette tip

Why is it possible to distinguish individuals by running these PCR products on a gel? a) The PCR products have different sequences b) The PCR products are the same length c) The PCR products have the same sequence d) The PCR products are different lengths

d) The PCR products are different lengths

What can a DNA ladder help determine? a) Whether or not DNA binds protein b) The origin of the DNA c) The DNA sequence of a fragment d) The length of a fragment

d) The length of fragment

The PCR products get a certain length due to whích fact? a) The DNA breaking off b) The DNA polymerase falling off C) The heat in the PCR machine d) The placement of the primers

d) The placement of the primers

What is electrophoresis?

laboratory technique used to seperate DNA, RNA, or protein molecules based on size and eletrical charge.

primers in PCR

they bind specific sites on the template of DNA to initiate and direct DNA synthesis.

Positively charged ions flow to the cathode. True or False?

true