Limited water supply is devastating since life has always depended on its presence. People, animals, and plants all need water to survive.
Some animals, especially those who inhabit arid climates, have evolved physiological defenses against lack of water. The camel is probably the best-known drought-resistant animal.
Contrary to popular opinion, camels do not carry water in their humps. The humps are a special kind of fat which supplies the camel with hydrogen. When this hydrogen mixes with the oxygen the camel breathes it forms water.
Plants have defense mechanisms that protect them against periodic dry spells. You have probably seen houseplants droop from lack of water. This is a sign that the plant’s defenses are working. The pores of the plant are sealed to prevent evaporation.
The plant goes into a sort of hibernation, slowing down its systems to expend less energy.