Phospholipids are the substance/structure that is the building block of the cell membrane. Without phospholipids, we wouldn't even have a cell membrane and wouldn't really have any way how to shield and guard or control th epassage of substances across the cell surface. The cell membrane is at the same time partially permeable; this means it will let certain ions that can be found in the intra and extracellular fluid in and out, while others will be kept from moving so freely.
Cohesion. Cohesion is the property of water that attracts other water molecules so they can stick together. Water is sticky because it has positive and negative charge in the oxygen and hydrogen ends that attracts one water molecule to another. Adhesion is also a property of water that attracts it from other substances, making it easy for water to travel upwards through transpiration.
Answer:
dear user nitrogen fixation is so important bcoz of the reasons given above
At the end of the winter they are most numerous in fresh water. they will cover surface of aquatic plants or poles and wooden borders of ponds. If you like to study them you can scrape the brown growth with a flat piece of plastic. you can also use a sponge. for the free living (plankton) species fine mesh plankton net is very useful.
