BIOLOGY---- 111 TEST |STUDY GUIDE EXAM PREPARATIONS
2025\2026
WITH ALL CORRECT ANSWERS TO BOOST YOUR GRADE
Central Dogma - answers DNA -> RNA -> Protein
3 stages of PCR - answers denaturation, annealing, elongation
Why did we use PCR in the forensic lab? - answers to make billions of copies of our
DNA
how to identify STR's - answers the nucleotides will repeat themselves over and over
(ATCT ATCT ATCT)
what did we put in the PCR mixture? - answers buffer, loading dye, DNA, primers, taq
polymerase and water
The DNA polymerase we used in the forensic labs because it could survive in high-
temperatures environments is called what? - answers taq polymerase
What's the importance of the buffer in the PCR mixture? - answers maintains pH levels
to prevent denaturation
What's the importance of the loading dye in with DNA in the PCR mixture? - answers -
the dye weighs down DNA so it can sink to the bottom of the wells and not float in the
buffer solution
- moves quicker than the DNA so indicates when to turn off the power
Importance of SYBR Green in gel? - answers - dye used in molecular biology
techniques to stain nucleic acids
- binds to DNA, resulting in a complex that absorbs blue light and transmits green
What's the importance of the 3 primers in the PCR mixture? - answers amplifies DNA
fragment
What's the importance of the taq polymerase in the PCR mixture? - answers it was the
enzyme
importance of the PCR primers in the forensic lab - answers short sequence of single-
stranded DNA that are complementary to DNA sequences that flank regions of interest.
it provided a "free" 3'-OH group to which the DNA polymerase can add nucleotides
denaturation definition - answers The DNA template is heated so the strands separate.
, Annealing definition - answers The reaction is cooled so the primers can stick to the
DNA template.
Extension definition - answers The temperature is changed to the ideal temperature for
Taq polymerase to build (synthesize) a new strand based on the template.
Thermocycler definition - answers The machine that controls the temperature of the
reaction and has been programmed to move through the heating and cooling steps.
The original DNA that you want to copy using PCR was what? - answers DNA template
Small sections of DNA that match ends of the template so it can be copied is called
what? - answers Primers
The solution that contains all the components--including enzymes, nucleic acids, and
ions--to build new DNA is what? - answers master mix
Individual nucleic acids (A, T, C, and G) that will be the building blocks when new
strands of DNA are made is called what? - answers dNTPs
What are you trying to amplify using PCR in this experiment? - answers Short tandem
repeats from specific genes
Why do the cheek cells need to be lysed before setting up PCR? - answers Lysing
breaks open the cells so the DNA is accessible.
Centrifuge function - answers Spins at a high speed to separate things by density
(denser stuff moves lower in the tube).
Thermocycler function - answers Can be programmed to keep samples/reactions at
specific temperatures for specific lengths of time.
Micropipette function - answers Measures and transfers very specific, usually small,
volumes of fluid accurately.
Chelex beads function - answers Bind metal ions so they can be removed from the
sample.
What does PCR stand for? - answers polymerase chain reaction
Which of the following will be components in your PCR mixture? - answers master mix,
human DNA
Lane 4 does not show any visible DNA. Which of the following are plausible reasons
there is nothing visible in this lane? - answers -PCR of that sample did not work so there
is no DNA fragment to be visualized.
2025\2026
WITH ALL CORRECT ANSWERS TO BOOST YOUR GRADE
Central Dogma - answers DNA -> RNA -> Protein
3 stages of PCR - answers denaturation, annealing, elongation
Why did we use PCR in the forensic lab? - answers to make billions of copies of our
DNA
how to identify STR's - answers the nucleotides will repeat themselves over and over
(ATCT ATCT ATCT)
what did we put in the PCR mixture? - answers buffer, loading dye, DNA, primers, taq
polymerase and water
The DNA polymerase we used in the forensic labs because it could survive in high-
temperatures environments is called what? - answers taq polymerase
What's the importance of the buffer in the PCR mixture? - answers maintains pH levels
to prevent denaturation
What's the importance of the loading dye in with DNA in the PCR mixture? - answers -
the dye weighs down DNA so it can sink to the bottom of the wells and not float in the
buffer solution
- moves quicker than the DNA so indicates when to turn off the power
Importance of SYBR Green in gel? - answers - dye used in molecular biology
techniques to stain nucleic acids
- binds to DNA, resulting in a complex that absorbs blue light and transmits green
What's the importance of the 3 primers in the PCR mixture? - answers amplifies DNA
fragment
What's the importance of the taq polymerase in the PCR mixture? - answers it was the
enzyme
importance of the PCR primers in the forensic lab - answers short sequence of single-
stranded DNA that are complementary to DNA sequences that flank regions of interest.
it provided a "free" 3'-OH group to which the DNA polymerase can add nucleotides
denaturation definition - answers The DNA template is heated so the strands separate.
, Annealing definition - answers The reaction is cooled so the primers can stick to the
DNA template.
Extension definition - answers The temperature is changed to the ideal temperature for
Taq polymerase to build (synthesize) a new strand based on the template.
Thermocycler definition - answers The machine that controls the temperature of the
reaction and has been programmed to move through the heating and cooling steps.
The original DNA that you want to copy using PCR was what? - answers DNA template
Small sections of DNA that match ends of the template so it can be copied is called
what? - answers Primers
The solution that contains all the components--including enzymes, nucleic acids, and
ions--to build new DNA is what? - answers master mix
Individual nucleic acids (A, T, C, and G) that will be the building blocks when new
strands of DNA are made is called what? - answers dNTPs
What are you trying to amplify using PCR in this experiment? - answers Short tandem
repeats from specific genes
Why do the cheek cells need to be lysed before setting up PCR? - answers Lysing
breaks open the cells so the DNA is accessible.
Centrifuge function - answers Spins at a high speed to separate things by density
(denser stuff moves lower in the tube).
Thermocycler function - answers Can be programmed to keep samples/reactions at
specific temperatures for specific lengths of time.
Micropipette function - answers Measures and transfers very specific, usually small,
volumes of fluid accurately.
Chelex beads function - answers Bind metal ions so they can be removed from the
sample.
What does PCR stand for? - answers polymerase chain reaction
Which of the following will be components in your PCR mixture? - answers master mix,
human DNA
Lane 4 does not show any visible DNA. Which of the following are plausible reasons
there is nothing visible in this lane? - answers -PCR of that sample did not work so there
is no DNA fragment to be visualized.
