In a hierarchical system of wildlife are three main levels: micro, mezosistema and macrosystem.


Micro - a molecular organic compounds.At this level, talk about life as such can only with great reservations, it is appropriate to define how prelife.Macrosystem - a population and environmental community combining organisms belonging to the same or different species.Mezosistema - is the level of organization of life, the appropriate body - the living body, is an autonomous system with signs of life: metabolism, reproduction itself in the offspring.


level mezosistemy uniform.Along with our own organism level it is isolated and the other hierarchical levels: the level of cell, tissue and organs.


cell




cell is a structural unit of a living organism.There are organisms that consist of one cell, but no substance which would not have cells.The only e
xceptions are viruses, but they belong to the number of living organisms in question.


Every cell is separated from the outside shell, but in its internal environment - the cytoplasm - are organelles elements, each of which performs a specific function.In multicellular organisms divided into somatic cells, providing vital functions of the body, and sex intended for breeding.In single-celled creatures, both functions are performed by a single cell.


Fabric




fabric is a system of cells, intercellular substance coupled with a similar structure and performing the same function in a multicellular organism.


In the evolution of the tissue were born thanks to the differentiation of cells in the colonies of single-celled organisms were located outside the cell, equipped with flagella, and providing motion in - cells like amoeba responsible for digestion.At the most primitive animals - in particular, in sponges - cells can be reversed.In organisms that are more highly evolved, tissues are resistant cell groups.These cells have the same genome, but they have different genes work, which explains the difference between cells that form different tissues.For example, cells sarcogenic person different from human erythrocytes more than muscle cells from cats.


Authority




Authority is a group of tissues that perform a specific function.Any body in a specific location in the body, its formation and development can be traced at all stages of development of the organism, from the period of organogenesis.In humans, this period starts on the third week of intrauterine life, and ends in the 4th month.


body aside only to a certain extent, to operate outside the body, he can not.Bodies are combined into a holistic system - for example, human nasal cavity, nasopharynx, trachea, bronchi and lungs form the respiratory system.Loss of or damage to any body affects the efficiency of the overall system.


body




top of the organismic level of organization of life - your own body.This integral living body, consisting of a single cell or a plurality of cells combined in tissues, organs and systems.


body - it is a separate individual, which is a structural unit of a higher level of organization of life - the population-species.