Composed of a phospholipid bilayer

The phospholipid bilayer builds the principle structural frame of the plasma membrane of the cell.

Explanation:

The plasma membrane of both plant and animal cell contain phospholipid bilayer in which the head group of the Phospholipid are oriented in opposite direction with respect to each other whereas the fatty acid tails of the two  layers faces each other each other in the phospholipid bilayer.

        The polar head group is present in the hydrophilic region whereas the non polar fatty acid tails are present in the hydrophobic region.

               Beside phospholipid  glycolipid,cholesterol and proteins are also present in the phospholipid bilayer.

                   Glycolipid contain oligosaccharide chain which play an important role in recognisation and binding of various molecules. Membrane proteins helps in the transport of various molecules in and out of the cell.whereas cholesterol regulates membrane fluidity.

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.