What requirement is for a template strand in dna replication?(choose from the option)
1.it serves as the starting point for teh new dna strand
2.it serves as a guide in determining the next nucleotide to be added according to the Watson-Crick base pairing scheme
3.it allows the dna polymerase to move along it easily
4.it is a substrate for the 3' - 5' exonuclease activity