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.
Phosphate group is the polar head: hydrocarbon chain becomes nonpolar tails 3. Phospholipids arrange themselves in a double layer in wa ter, so the polar heads face outward toward water molecules and nonpolar tails face toward each other away from water molecules. 4.