The levels of organization refer to how living things are arranged from the smallest building blocks (atoms and molecules) to larger structures like cells, tissues, organs, and organ systems, and finally to complete organisms and ecosystems. The levels of the organization are as follows:
The atomic level of organization: The atomic level of the organization refers to the smallest and most basic unit of matter, which is the atom. Each atom is composed of sub-atomic particles, called electrons, protons, and neutrons, atom retains the properties of an element. In nature, there are more than 100 kinds of elements, and among these 16 elements are called bio-elements, which are vital for life. Only six elements, Carbon, Hydrogen, Oxygen, Sulphur, nitrogen, and Phosphorous are called basic elements of life.
The molecular level of organization: Atoms combine to form molecules. These organic molecules of cells are called bio-molecules. They are classified as:
micro-molecules: are small molecules with less molecular weight, examples are glucose, amino acid, and fatty acids.
macromolecules: are large molecules with greater molecular weight, examples are carbohydrates, proteins, and lipids.
The cellular level of organization: At the cellular level, the molecules work together to form the various organelles and structures within the cell. Molecules play a crucial role in cellular processes and functions.
Cell: a cell is the basic unit of living organisms.
Tissues: When a similar type of cells organizes together in a group, it’s called tissues.
Organs: The different types of tissues arranged in a particular manner to work together are called Organs.
Organ system: Organs of different types work in a coordinated manner to perform a function called an Organ-system.
Multicellular Organism: When different organ-system function in co-ordination as a unit, they form a body or Multicellular Organism
Taxonomic level: Taxonomic level refers to the different levels of classification that are used to group living organisms based on their shared characteristics. These levels range from very broad categories (like "Kingdom") to more specific ones (like "Species").
Population-level: All the members of a species, living in specific habitat are called Population. For example, a group of parrots living on the tree is called the parrot population.
Community level: The members of different species living in specific habitats are called a Community. A group of different kinds of birds, living on the tree, is called a bird community.
Ecological system: Communities always depend on their non-living environment. For example, oxygen for respiration is obtained from the environment and in turn, gives out carbon dioxide. This interaction is called Ecosystem or Ecological system.
Biosphere level: The biosphere level refers to the highest level of biological organization that includes all living organisms and their interactions with each other and their environment. The part of the earth where life exists is called the biosphere. It consists of different kinds of ecosystems.
