Final answer:
Primers are needed in PCR for several reasons: they provide a starting point for DNA replication, determine the target DNA sequence, and initiate replication. Overall, primers are crucial for the success of PCR as they allow specific DNA sequences to be selectively amplified.
Step-by-step explanation:
PCR, or Polymerase Chain Reaction, is a laboratory technique used to amplify DNA sequences. Primers are needed in PCR for several reasons: Primers provide a starting point for DNA replication. They bind to the DNA template and allow DNA polymerase to add complementary nucleotides.
Primers determine the target DNA sequence to be amplified. They are designed to be complementary to the DNA region of interest. Primers are necessary for the initiation of replication, as they provide a free 3'-hydroxyl group for DNA polymerase to add nucleotides. Overall, primers are crucial for the success of PCR as they allow specific DNA sequences to be selectively amplified.