No.
Highest resistance when reverse biased - no current flow.
Forward biased, low resistance, current flows, just like an ordinary diode. But these are small devices, the current flow (power handling capability) is low (unlike big power devices which can handle high current levels).
This is what I can't get my head around. If it is low resistance in use, why use a parallel resistor? (Back to the 1/R scenario)
