Why does DNA have a leading strand and a lagging strand during replication?___has to attach the new free-floating nucleotides to the _____ of the newly formed strand. The two strands of a DNA molecule are antiparallel, so in order for the lagging strand to be formed in the same direction, it has to be done in Okazaki fragments going in a ___3rd___ direction.

 

1st  2nd  3rd  DNA polymerase  3' end  5' to 3' 

1st  2nd  3rd  DNA ligase  3' end  5' to 3' 

1st  2nd  3rd  DNA helicase  5' end  3' to 5' 

1st  2nd  3rd  DNA polymerase  5' end  3' to 5'