I encountered the same problem when I first started printing, and here is what I found was my problem: The Bowden Tube was not pushed far enough down and left a gap between the end of the tube and the nozzle, causing the prints to have bad layers like yours. What I did to solve this was heat up my extruder to 220+ degrees, took the nozzle and Bowden Coupler off and poked theBowden tube clear through, picked off the gummy filament on the end of it, and repeated till it came out clean (make sure to pull your filament back a little ways first so that it is not clear at the end of the tube). After this, what i did to ensure that I would have the Bowden tube close enough was cut a piece that was short enough to fit between the nozzle and the Bowden Coupler and pushed down hard inside the extruder to make sure that it was as far down as it should be. Let me know if this works.