What are the levels of organization of the subject?

We explain what are the levels of organization of the subject, the ways in which it can be divided and its main characteristics.

1. What are the levels of organization of the subject?

When we talk about the levels of organization of matter, we refer to the possible divisions or stratifications in which it is possible to study all known matter , especially organic ( living beings ), going from a more general and simple perspective to a more detailed one. and of increasingly complex relationships.

While all matter in the universe is made up of a finite number of atoms , they are combined and organized at such densely complex levels that the fundamental building blocks of it are lost sight of. That is why layers or levels of organization can be identified as we increase or decrease the scale .

For example, a human being is made of atoms, no doubt, of the same type as a planet is made of (we agree that there will be many more atoms on the planet, given their dimensions), but organized differently. The same as between a human being and a cell , since the first one contains millions of these.

So the matter is organized in levels of complexity that we can state separately. These are, from least to greatest:

• Subatomic level . Thanks to atomic physics, we know that atoms are composed of smaller particles, which are protons (with charge +), neutrons (without charge) and electrons (with charge -). The first two are in the nucleus of the atom and the last orbit around it.
• Atomic level . The fundamental bricks of matter are atoms, whose complete classification appears in the Periodic Table of the elements. 118 are known so far and it is known that everything that exists is made from combinations of these atoms. Two atoms of the same element will always be identical, so our hydrogen atoms are equal, to say the least, to those of the Sun.
• Molecular level . Atoms join together, of the same type or of different types, for various reasons of electromagnetism or chemical bonds by valence (to share electrons from the outermost layer). Thus the molecules are formed, which can be as simple as two identical atoms (O2, the oxygen molecule) or several different atoms (C6H12O6, the glucose molecule). These molecules can build increasingly complex structures, such as amino acids and then proteins , essential for life.
• Cellular level . A cell is the minimum unit of life: all living beings are composed of at least one cell (some of only one of them, called  unicellular ; those of more than one,  multicellular ). The cell walls, the enzymes within it, the DNA , everything is formed from extremely complex molecules.
• Tissue or tissue level . The cells are grouped together, according to their functions and needs within a complex system that is the organism. For example, the cells of a muscle, say, a frog leg, all fulfill the same function and share their physical characteristics. This group of common cells is called tissue: muscle tissue, in this case, but also vascular tissue, nerve tissue, etc.
• Level bodies . The organs of the body of a living being, as is clear from the above, are composed of tissues. Thus, the heart of heart tissue, the liver of liver tissue, etc.
• System or device level . The different organs and tissues of the body cooperate, help each other, or work together. Each of the circuits of organs and tissues that carry out specific functions fundamental to the organism are known as a system or apparatus, such as the cardiovascular system, which comprises the organs involved in circulation and breathing .
• Level body . The total organs, tissues and cells of a living being make it up, and define it as an individual, that is, an organism. It is one more among many similar, but it is at the same time one, unrepeatable, with a unique DNA.
• Population level . Organisms of similar characteristics tend to come together to reproduce, take care of themselves and share the way of life, in small groups or colonies. This is known as population .
• Species level . If we gathered all existing populations of organisms of the same type (which share physical and genetic characteristics), we would have the total of that species on the planet. There are millions of species of living beings on Earth.
• Ecosystem level . The populations and species do not live apart from the others, but are interconnected with them through trophic chains (food) in which there are producers, herbivores, carnivorous predators and finally decomposers . A circuit of interconnected species like this and located in a specific habitat , we will call it an ecosystem .
• Biome level . Ecosystem clusters around the same climate or geographic region constitute biomes .
• Biósfera level . This is the name of the ordered set of all living beings, the inert matter and the physical environment in which they find themselves and with which they relate in different ways.
• Planetary level . Although life as we know it exists only on Earth, so far, this is just one more than millions of planets of different size and constitution, orbiting even more massive suns and in eternal fusion of their atomic elements in space.