What three enzymes are used during dna replication? describe what each does during replication.

DNA helicase- Unwinds the DNA strand in preparation for replication. 

DNA polymerase- Replicates the base pairs of the strand, producing a new strand of DNA. 

DNA ligase- Reconnects the severed DNA strand after replication. 

The truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey