<prompt> Addition of PUFA in plasma membrane causesMembrane becomes rigidIncrease in fluidity of membraneDecrease in fluidity of membraneNo change in fluidity of membrane  <response>: Ans. is b i.e. increased fluidity of membranes : As explained previously in NOV 2000 paperThe fluidity of the plasma membrane is highly dependent upon the lipid composition of the membrane . Saturated fatty acids : Increase the transition temperature and hence decrease the fluidity.Unsaturated fatty acids PUFA : Decrease the transition temperature and hence increase the fluidity of membrane. 