<prompt> Function of cholesterol in plasmalemma is toIncrease the fluidity of lipid bilayerDecrease the fluidity of lipid bilayerFacilitate the diffusion of ions into the lipid bilayerAssist in the transpo of hormones across the lipid bilayer  <response>: The fluidity of the lipid bilayer is decreased in following three ways Lowering temperature Increasing saturation of fatty acyl tails in phospholipid membrane Increase membrane cholesterol content. Cholesterol interacts with the phospholipid membrane containing fatty acyl chains, compacting them, constraining the motion in bilayers, hence decreasing the fluidity. Ref: Lehninger 30e pg 395. 