1.2 - Replication of DNA

• what is the function of DNA polymerase?

  To add nucleotides to the 3’ end of a single DNA strand
• what is a primer?

  a short strand of nucleotides which binds to the complementary sequence of single stranded DNA
• why is the lagging strand replicated in fragments?

  DNA polymerase can only add nucleotides to the 3’ end of a DNA strand
• what is the function of Ligase?

  to join DNA fragments on the lagging strand
• what is PCR?

  Polymerase Chain Reaction
• what are primers in PCR?

  short strands of nucleotides which are complementary to specific target sequences at the two ends of the region of DNA to be amplified
• what is the function of PCR?

  to AMPLIFY the target region of DNA
• what is step 1 of PCR?

  Denaturing - DNA is heated to 95°C to separate the strands
• what is step 2 of PCR?

  Annealing - DNA is cooled to 60°C to allow primers to bind to the target sequences
• what is step 3 of PCR

  Extending - DNA is heated to 75°C for heat tolerant DNA polymerase to replicate the region of DNA
• what are practical applications of PCR?

  * Diagnosing genetic disorders

  * Solving Crimes

  * Settling Paternity Suits