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Introduction to Polymerase Chain Reaction quiz #1 Flashcards

Introduction to Polymerase Chain Reaction quiz #1
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  • What is the primary purpose of Polymerase Chain Reaction (PCR)?
    The primary purpose of PCR is to make many identical copies of DNA in a test tube very quickly and efficiently.
  • How does PCR differ from DNA cloning in terms of location?
    PCR occurs within a test tube, whereas DNA cloning occurs within a cell.
  • What are the four main components required for a PCR mixture?
    The four main components are template DNA, DNA primers, thermostable DNA polymerase (Taq polymerase), and all four DNA nucleotides.
  • What role do DNA primers play in PCR?
    DNA primers are complementary to the opposite strands of DNA and serve as the starting point for DNA amplification.
  • Why is Taq polymerase commonly used in PCR?
    Taq polymerase is a thermostable DNA polymerase that can withstand the high temperatures required for DNA denaturation.
  • What is the formula to determine the number of new copies of template DNA made at each PCR cycle?
    The formula is 2 raised to the power of n, where n represents the number of PCR cycles.
  • What happens during the denaturation step of PCR?
    During denaturation, the DNA is heated to high temperatures, causing the two strands to separate.
  • What occurs during the annealing step of PCR?
    During annealing, DNA primers bind to the single-stranded DNA at cooler temperatures.
  • What is the purpose of the extension step in PCR?
    During extension, Taq polymerase builds new DNA strands by extending from the primers in the 5' to 3' direction.
  • How long does a typical PCR process take compared to DNA cloning?
    A typical PCR process takes about 1.5 to 2 hours, whereas DNA cloning can take well over 24 hours.
  • What is the significance of using a thermostable DNA polymerase in PCR?
    A thermostable DNA polymerase, like Taq polymerase, is essential because it can function at the high temperatures needed for DNA denaturation.
  • What is the role of deoxyribonucleotides in PCR?
    Deoxyribonucleotides are the building blocks used to synthesize new DNA strands during PCR.
  • How does PCR contribute to forensic science?
    PCR can amplify small amounts of DNA from a crime scene, providing enough material for forensic analysis.
  • What is the exponential growth pattern of DNA copies in PCR?
    The number of DNA copies doubles with each cycle, following the formula 2^n, where n is the number of cycles.
  • What are the three main steps in each PCR cycle?
    The three main steps are denaturation, annealing, and extension.
  • What does PCR stand for in molecular biology?
    PCR stands for Polymerase Chain Reaction.
  • What is the primary purpose of PCR in DNA studies?
    The primary purpose of PCR is to amplify a specific sequence of DNA.
  • How does PCR differ from DNA cloning?
    PCR amplifies DNA in a test tube without living cells, while DNA cloning uses living cells to replicate DNA.
  • What does the term 'amplify' mean in the context of PCR?
    In PCR, 'amplify' refers to making many copies of a specific DNA sequence.
  • How many copies of DNA can PCR produce from a single gene?
    PCR can produce up to 1,000,000,000 copies of a single gene.
  • Does PCR remove introns from the DNA sequence it amplifies?
    No, PCR does not remove introns; it copies the DNA sequence as it is.
  • What is the role of restriction enzymes in DNA studies?
    Restriction enzymes cut DNA segments to create complementary sticky ends, not amplify DNA.
  • What happens to the amount of DNA with each cycle of PCR?
    The amount of DNA doubles with each cycle of PCR.
  • Is PCR used to determine the sequence of a DNA region?
    No, determining the sequence of a DNA region is the role of DNA sequencing, not PCR.
  • What is the difference between aerobic and anaerobic processes in cellular biology?
    Aerobic processes require oxygen, while anaerobic processes do not.
  • What is the significance of the active site in enzyme function?
    The active site is where substrates bind and reactions are catalyzed by the enzyme.
  • What is the role of ATP in cellular activities?
    ATP (Adenosine Triphosphate) provides energy for various cellular processes.
  • What is the function of DNA polymerase in PCR?
    DNA polymerase synthesizes new DNA strands by adding nucleotides to a template strand.
  • What is the difference between a gene and an allele?
    A gene is a segment of DNA that codes for a trait, while an allele is a variant form of a gene.
  • What is the role of a primer in PCR?
    Primers are short DNA sequences that initiate DNA synthesis during PCR.
  • can you correctly identify the steps in the polymerase chain reaction (pcr)?
    The polymerase chain reaction (PCR) involves three main steps: denaturation, annealing, and extension. 1) Denaturation: The double-stranded DNA is heated to around 94-98°C to separate it into two single strands. 2) Annealing: The temperature is lowered to 50-65°C to allow primers to bind to the complementary sequences on the single-stranded DNA. 3) Extension: The temperature is raised to 72°C, and the thermostable DNA polymerase (such as Taq polymerase) synthesizes a new DNA strand by adding nucleotides to the primer. These steps are repeated for 20-40 cycles to exponentially amplify the target DNA sequence.