Biology, from the greek bio(s), “life” and logeia, (by logein) “discoursed” means study of life and runs from the biosphere, so on a scale very large to the very small (microscopic) of cells or molecules. As you can see in the diagram at the top of the hierarchy is the biosphere, l ’ set of environments that support life and maintain.
By choosing a specific area land, ’ aquatic or air we find a ecosystem, that includes all forms of life and not (air,water,soil, sunlight,..) in a given area.
L ’ set of organisms that live in a particular ecosystem is defined community. All ’ within the community they live many different organisms, each of these forms of life belongs to a certain species with its own population of individuals.
The population ’ is the set of entities belonging to the same species.
Below the population is the single living being, that is, a organism. Nell ’ organism there are a whole host of lower levels, Initially we find the organ system, such as the nervous system or the lymphatic, this consists of several organs. The organs are composed of several fabrics (muscle, nervous, connective tissue,…) they perform different functions each. Muscle tissue will consist cells muscles, separated from the surrounding environment from membranes ’. All ’ within the cell are different structures, also called organelles performing certain tasks necessary for the life and development of the cell. Finally we find the level molecular, which is composed in turn from very small particles, the atoms.