How is life organized?
Do you ever wonder how a single cell can become a complex organism like a human being or giants like blue whale? The answer lies in the different levels of organization of life. From the smallest atoms and molecules to the largest ecosystems and biosphere, all living things are organized in a hierarchical fashion.
Each level of
organization is dependent on the levels below it. For example, cells cannot
function without organelles, and organisms cannot function without cells or
organ systems. The levels of organization are also interconnected.
The levels of
organization of life provide a framework for understanding the complexity of
life. They also help us to understand how living things function and interact
with each other.
13 levels of organization of
life
- Subatomic particles: The smallest units of matter, such as protons, neutrons, and electrons.
- Atoms: The basic building blocks of matter, composed of subatomic particles.
- Molecules: Groups of atoms that are bonded together. Two oxygen (O) atom combines to form oxygen molecule (O2)
- Organelles: Specialized structures made up of aggregates of macromolecules within a membrane that carry out specific functions.
- Mitochondrion involved in ATP synthesis, chloroplast in photosynthesis
- Cells: The basic smallest unit of life, capable of carrying out all the basic functions of life such as growth, metabolism, reproduction etc.
- Tissues: Groups of cells that are similar in structure and function.
- Tissues include epithelial tissue, muscle tissue, nervous tissue etc
- Organs: Structures that are composed of multiple tissues and that work together to perform a specific function. Organs include brain, kidney, liver etc.
- Organ systems: Groups of organs that work together to carry out a major function of the body. Organ systems such as digestive system, circulatory system etc.
- Organisms: made up of organ systems that work together to perform different life functions. Individual living things, such as plants, animals, bacteria etc.
- Populations: Groups of organisms of the same species that live in the same area. A pride of lion with a territory or living in a specified area
- Communities: Groups of populations that interact with each other in a particular environment. In African savannah, there are different communities like lions, zebra, hyena etc.
- Ecosystems: Communities of organisms that interact with each other and with their physical environment.
- Ecosystems include grassland ecosystem, desert, tundra, taiga
etc.
- Biosphere: The entire region of Earth that is inhabited by living things. It comprises of all ecosystems and are made up of biomes.