A plough (UK) or plow (US; both /ËplaÊ/) is a tool or farm implement used in farming for initial cultivation of soil in preparation for sowing seed or planting to loosen or turn the soil. Ploughs were traditionally drawn by working animals such as horses or cattle, but in modern times are drawn by tractors.
Polar/Nonpolar Regions. In a biological membrane, the phospholipids are organized into a bilayer, which serves as the framework in which the other components of the membrane are embedded.
The lipid bilayers that are found in cell membranes have two important characteristics. One of them is that most polar molecules cannot go across the membrane. Polar molecules are attracted to the water inside the cell or to the water outside the cell.However, they cannot interact with the nonpolar tails of the phospholipids within the lipid bilayer. The result is that the interior part of the cell membrane forms a non polar zone that acts as a barrier to polar molecules.hospholipids are molecules that make up the framework of the cell membrane..Phospholipids are lipids in which the long chains or tails are joined to a short polar head that contains phosphorus. The long tails are nonpolar, so water molecules will tend to push them away.