test Flashcards
What is the function of primers in a PCR reaction?
- Bind specific sites on the DNA
– Denature DNA
– Bind random sites on the DNA
– Copy DNA
Bind specific sites on the DNA
What does a DNA polymerase do?
- Synthesizes DNA
– Degrades proteins
– Unfolds DNA
– Cleaves DNA
Synthesizes DNA
For which enzyme are nucleotides the substrate?
– Ligase
– Ribosome
– Protease
- DNA polymerase
DNA polymerase
What is the template of the PCR reaction?
- DNA
– RNA
– Proteins
– Nucleotides
DNA
What do you need to do each time before using a pipette to collect liquid?
– Polish the pipette
– Shake the pipette
– Put on a used pipette tip
- Put on a new, sterile pipette tip
Put on a new, sterile pipette tip
Why is it important to change the pipette tip?
- To avoid cross contamination
– To keep the lab assistant happy
– To employ more garbage men
– To keep the lab bench clean
To avoid cross contamination
How did you collect liquid in the lab?
– Grabbing it with my hands
– Using a measuring cup
– Pouring from the bottle
- Using a pipette
- Using a pipette
At this step in the PCR process, what happens to the DNA?
- It will be separated into two strands
– It will be twisted into a double helix
– It will be broken into many pieces
– It is kept intact
It will be separated into two strands
How is the DNA separated into single strands?
- The high temperature (95 °C)
– The primers separate the two DNA strands
– The DNA polymerase separates the two DNA strands
– The low temperature (54 °C)
- The high temperature (95 °C)
What is the step in the PCR reaction that is now shown called?
- Annealing
– Denaturation
– Copying
– Extension
Annealing
The area where the primers bind marks which part of the PCR product?
– End, 5’5 prime-end
– Beginning, 3’3 prime-end
– End, 3’3 prime-end
- Beginning, 5’5 prime-end
- Beginning, 5’5 prime-end
The PCR products get a certain length due to which fact?
- The placement of the primers
– The heat in the PCR machine
– The DNA breaking off
– The DNA polymerase falling off
The placement of the primers
How does the DNA polymerase extend the primers into a new DNA strand?
– Adding nucleotides to the 3’ and 5’ ends of the primers
– Adding nucleotides to the 5’ end of the primers
– Adding more primers to the strand
- Adding nucleotides to the 3’ end of the primers
Adding nucleotides to the 3’ end of the primers
Primers are always designed to be complementary to the template DNA strand. Which
of these sequences is the complementary sequence to the template sequence 5’5 prime-GTGGTCTGATCAACGGTAA- 3’3 prime?
– 3’-GTGGTCTGATCAACGGTAA-5’
– 5’-GTGGTCTGATCAACGGTAA-3’
– 5’-CACCAGACTAGTTGCCATT-3’
- 3’-CACCAGACTAGTTGCCATT-5’
3’-CACCAGACTAGTTGCCATT-5’
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?
- It decreases
– It results in a match
– It is not affected
– It increases
- It decreases
How many copies of DNA are required to see bands on the electrophoresis gel?
– 10 copies
– 1000 copies
– None
- Millions of copies
Millions of copies
DNA is negatively charged. To which location in the electrophoresis gel does it
migrate?
- Positive pole
– Corners
– Sides
– Negative pole
Positive pole
What are the building blocks of new copies of DNA?
- Nucleotides
– Polymerase
– Amino acids
– Primers
Nucleotides
What is the function of primers in a PCR reaction?
– To separate double stranded DNA in order to initiate and direct DNA synthesis
– They bind random stretches of DNA to initiate and direct DNA synthesis
– Their only function is to bind DNA and they do not direct DNA synthesis
- They bind specific sites on the template DNA to initiate and direct DNA synthesis
They bind specific sites on the template DNA to initiate and direct DNA synthesis
Which reagent acts as a template for the DNA polymerase, so it knows which new
DNA to make?
- DNA from a blood sample
– Proteins in the blood cells
– Primers
– Nucleotides
DNA from a blood sample
DNA polymerase binds to the template DNA. In which direction is the new DNA
subsequently synthesized?
- 5’ → 3’
– Random
– 3’ → 5’
– 5’ → 3’ and 3’ → 5’
5’ → 3’
Why is the Taq-polymerase special compared to most other polymerases
- It can resist high temperatures
– It unfolds DNA
– It can resist low temperatures
– It synthesizes DNA
It can resist high temperatures
What can contamination of reagents leads to?
- Unreliable results
– Good results
– Reproducable results
– Reliable results
Unreliable results
What is the purpose of PCR?
- To copy and then make many copies of a specific region of DNA
– To reveal the sequence of a piece of DNA
– To make few copies of DNA
– To copy the entire human genome
To copy and then make many copies of a specific region of DNA
Why is a PCR cycle repeated 30 times?
– To avoid adding new reagents every cycle
– To allow the polymerase to work
– To make sure the PCR machine is working
- To get enough DNA
To get enough DNA
What can a DNA ladder help determine?
- The length of a fragment
– The origin of the DNA
– The DNA sequence of a fragment
– If DNA binds protein
The length of a fragment
Why is it possible to distinguish individuals by running these PCR products on a gel?
– The PCR products have different sequences
– The PCR products have the same sequence
- The PCR products are different lengths
– The PCR products are the same length
The PCR products are different lengths
