<prompt> All of the following statements are true except ?PGs and leukotriences are derived from arachidonic acidCox-I is an inducible enzymeCox II is induced by cytokines at sites of inflammationLeukotrienes cause smooth ms. constriction  <response>: Ans. is b i.e., Cox I is an inducible enzymes o Cox-2 is an inducible enzyme, not Cox-1. 