Three different living things could be humans which are part of the mammal group, snakes which are part of the group of reptiles and insects.
Although the three different animals mentioned above are not all part of the same species, they all need three basic things to survive even though each species is adapted to survive in different conditions. Across every life form on Earth, scientists have been able to identify four essential needs that are needed for survival.
Not all beings on Earth need oxygen, but every species needs air. In volcanic vents there are species that have adapted to survive by breathing sulfurous gases. Humans use air to live by breathing in oxygen and breathing out carbon dioxide, whereas fish filter oxygen out of the water through their gills. All species have adapted some sort of respiratory system to suit their environment.
Water is essential for every life form on Earth. This is because it usually makes up a large percentage of the body mass of a living organism, for example, humans are believed to be made up of 70 per cent water. Water is essential for regulating body temperature, keeping blood flowing, circulating nutrients and expelling waste. Although different organisms may have different methods for ingesting water, it is still essential for each one.
All organisms require some sort of food intake that their bodies can then convert into energy that is used to maintain life processes such as circulation, digestion and respiration. Obviously, the method that is used to take in this energy is different for each species, for example, humans eat food to provide energy whereas plants use photosynthesis.
Homeostasis is the body's equilibrium process that keeps all bodily functions stable and running correctly. All species have the internal ability to keep their systems balanced and stable. For example, humans sweat and shiver to control their internal body temperature when outside conditions fluctuate. Many species can only survive in certain conditions, so a stable environment that allows homeostasis is essential for the continued existence of many life forms.
