How can jellyfish and starfish survive without a brain? How would they move?

Question: How can jellyfish and starfish survive without a brain? How would they move?
- Keywords:
  brain,
  jellyfish,
  move,
  starfish
Asked by millie123 to Joe on 7 Nov 2016.
- Joe Bathelt answered on 7 Nov 2016:
  
  A brain is basically a lot of nerve cells in one spot. Jellyfish and starfish also have nerve cells. Their nerve cells are distributed all around their body rather than being in one spot. The use nerve cells to coordinate muscles in order to move, just like other animals do.

Question: How can jellyfish and starfish survive without a brain? How would they move?