test

Question 1

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

Answer 1

Bind specific sites on the DNA

Question 2

What does a DNA polymerase do?
- Synthesizes DNA
– Degrades proteins
– Unfolds DNA
– Cleaves DNA

Answer 2

Synthesizes DNA

Question 3

For which enzyme are nucleotides the substrate?
– Ligase
– Ribosome
– Protease
- DNA polymerase

Answer 3

DNA polymerase

Question 4

What is the template of the PCR reaction?
- DNA
– RNA
– Proteins
– Nucleotides

Answer 4

DNA

Question 5

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

Answer 5

Put on a new, sterile pipette tip

Question 6

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

Answer 6

To avoid cross contamination

Question 7

How did you collect liquid in the lab?
– Grabbing it with my hands
– Using a measuring cup
– Pouring from the bottle
- Using a pipette

Answer 7

• Using a pipette

Question 8

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

Answer 8

It will be separated into two strands

Question 9

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)

Answer 9

• The high temperature (95 °C)

Question 10

What is the step in the PCR reaction that is now shown called?
- Annealing
– Denaturation
– Copying
– Extension

Answer 10

Annealing

Question 11

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

Answer 11

• Beginning, 5’5 prime-end

Question 12

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

Answer 12

The placement of the primers

Question 13

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

Answer 13

Adding nucleotides to the 3’ end of the primers

Question 14

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’

Answer 14

3’-CACCAGACTAGTTGCCATT-5’

Question 15

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

Answer 15

• It decreases

Question 16

How many copies of DNA are required to see bands on the electrophoresis gel?
– 10 copies
– 1000 copies
– None
- Millions of copies

Answer 16

Millions of copies

Question 17

DNA is negatively charged. To which location in the electrophoresis gel does it
migrate?
- Positive pole
– Corners
– Sides
– Negative pole

Answer 17

Positive pole

Question 18

What are the building blocks of new copies of DNA?
- Nucleotides
– Polymerase
– Amino acids
– Primers

Answer 18

Nucleotides

Question 19

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

Answer 19

They bind specific sites on the template DNA to initiate and direct DNA synthesis

Question 20

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

Answer 20

DNA from a blood sample

Question 21

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’

Answer 21

5’ → 3’

Question 22

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

Answer 22

It can resist high temperatures

Question 23

What can contamination of reagents leads to?
- Unreliable results
– Good results
– Reproducable results
– Reliable results

Answer 23

Unreliable results

Question 24

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

Answer 24

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

Question 25

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

Answer 25

To get enough DNA

Question 26

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

Answer 26

The length of a fragment

Question 27

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

Answer 27

The PCR products are different lengths