AP BIOLOGY

Detailed explanation-1: -Living organisms need water because it plays a vital role in the reactions taking place within organism’s cells and body. Water acts as a universal solvent, providing a medium for the chemical reactions to occur. Substances are also transported from one part of body to the other in the dissolved state.

Detailed explanation-2: -Water’s extensive capability to dissolve a variety of molecules has earned it the designation of “universal solvent, ” and it is this ability that makes water such an invaluable life-sustaining force. On a biological level, water’s role as a solvent helps cells transport and use substances like oxygen or nutrients.

Detailed explanation-3: -Most acids dissolve in water to yield the corresponding anions. Many substances in living organisms, such as proteins, DNA and polysaccharides, are dissolved in water. Water also dissolves many gases, such as oxygen and carbon dioxide.

Detailed explanation-4: -Because of its polarity and ability to form hydrogen bonds, water makes an excellent solvent, meaning that it can dissolve many different kinds of molecules.