drawcalls using particles on ios

I want to use some particles on ios but I'm confused about how they work. Does each particle require 1 draw call? I've heard that it's important to limit the number of draw calls if possible to around 40 which seems difficult if there are more than a 40 particles in a scene.

Does the new 3.5 particle system use particles more efficiently than the old particle system?

Thanks for any tips on using particles on ios,