Is dna synthesized continually during the cell cycle

  No 
DNA is synthesized in the middle part of Interphase, which is usually denoted S in the series G1 - S - G2  "There are 3 stages of interphase: G1 in which the cell grows and functions normally. Once it grows too large it enters the synthesis (S) phase. In S phase the cell makes exact copies of its DNA. It is now ready for G2 phase where it makes sure all of its chromosomes and organelles are ready for mitosis."

If you get a map and put the countries a states all together it forms all one piece you can also tell because of the earth quakes