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Levels of Organization in the Living World

The cell is the fundamental building block of life and also the fundamental level of organization in our body. Tissues are groups of cells that perform essentially the same functions and then, the next higher level of biological organization of tissue, which is much organized, is called organs that carry out the numerous function of our body. The different organs which coordinate with one another that perform a common function form another level of organization called organ system; various organ systems work harmoniously with each other in forming and maintaining the body of the organism.

Organisms, therefore, are made up of smaller parts at each level of organization. Each small part has its own role to play to keep the system going. All parts, however, must play together to maintain life, just like in an orchestra, as a member you must play together to create a symphony.

globe via morgueFile

globe via morgueFile


An organism is the lowermost level of organization in an ecosystem or what we call the living world. It is an individual that has all the special characteristics of the species it represent. As a member of the species, the organism exhibits a characteristic lifetime pattern of growth development, storage and reproduction. Below is the classification of organism that has been controversial throughout time, which is considered too as kingdoms:

  • Monera
  • Protista
  • Fungi
  • Plantae
  • Animalia

An organism has different sizes and shapes it can be small or large, simple or complex, useful to people or a pest. It can also be made up of a single cell like Paramecium or many cells as in man.


Population refers to the total inhabitants living in a specific area such as in cities, forest, coral reefs and other physical environment. “No man is an Island” so no organism must exist in isolation. A group of interbreeding individuals in a particular place at a given time is called a population. When individuals of the same kind interbreed or intercourse they are likely to reproduce fertile offspring that will cause their number to out-grow and multiply.

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Biotic community

This is composed by living organisms such as plants, animals and microorganisms which interact with one another and live together as a abiotic community. This is the next higher level of organization in the living world. A biotic community is kept alive by the interaction of the various species living together within a defined boundary. They thrive and maintain the system in the community for existence.

The species is a biotic community performs different functions. Producers such as plants produce food for the community. They are also known as “autotrophs”. Consumers (macroconsumers) are the one who consumes, rely and feed on plants which are also known as “heterotrophs”. And decomposers which are sometimes called saprotrophic are the organisms that maintain the balance between the living and the dead by decomposing organic matters. An example of this biotic community is:

  • Aquarium
  • Fish Pond
  • Coral Reefs
biosphere via morgueFile

biosphere via morgueFile

Ecosystems refer to a place or a biotic community where living organism thrives and interacts with the Abiotic factors or the nonliving environment. It is where organism lives with the physical environment. A smaller unit which is habitat is a type of environment where organisms live and there are different types of habitats like marine, terrestrial, water and land habitats.


It is the earth’s zone air, soil and water that is capable of supporting life. In this zone, life depends primarily on the sun’s energy through the process of photosynthesis.

The surface of the earth is practically covered with ecosystems either land or water ecosystem such as the oceans, forests, grasslands, lakes, cities and so on. Their boundaries generally overlap. The network of ecosystems all over the earth’s surface establishes the biosphere.

References ; Wikipedia, the free encyclopedia , Science and Technology by Lilia M. Rabago Ph. D , Crescensia C. Joaquin Ph.D, Catherine B. Lagunzad , PH. D, Encarta

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