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 nonpolar regions of the molecules, which are referred to as hydrophobic, face the interior of the bilayer, where they are shielded from water. On the other hand, the polar regions of the molecules, termed hydrophilic, face outward where they interact with the water inside and outside of the cell.