LEVELS OF ORGANIZATION REVIEW
The most specific or smallest level of organization are the subatomic particles which include the
protons, neutrons, and electrons. When the subatomic particles come together, a structure
called the atom is formed. In order to see a whole list of atoms, we can refer to the periodic table.
The most common or important examples of atoms in biology are carbon, hydrogen, and oxygen.
Many combinations of atoms exist in our world, forming a molecule. However, joining 2 hydrogen
atoms with an oxygen atom forms water, while joining a carbon with 2 oxygen forms carbon
dioxide. When these smaller molecules are bonded or joined together, larger structures called
macromolecules form. There are only 4 groups that make up our entire body. Three examples are
carbs, proteins, and lipids, leaving the 4th group consisting of DNA called nucleic acids.
Together the macromolecules make up organelles, which literally means tiny organ. The most
important organelle is the nucleus. Three other examples include ribosomes, cytoplasm,
vacuole. The organelles work together to make up the cell. There are 2 types, the type that has a true
nucleus called eukaryotic, and the type that has no true nucleus called prokaryotic. Cells
performing the same function make up a tissue. Tissue performing a common function make up an
organ. Examples of organs include the heart, lung, liver. The organs that work together in a
process are called an organ system. Examples include the main system involved in food breakdown
called the digestive system, and the system that includes your brain called the nervous system.
The systems make up one individual called an organism. The most common example to us is a
human! Although another example of an organism is a catfish. A group of individuals of the same
species in the same place and same time is called a population. An example of a population could
include all the catfish in a pond. If we consider that pond, and there is a population of catfish
already accounted for, we can now consider all the biotic factors. All the living factors in the pond
would make up a community. If we still consider the pond and all the living factors make up a
community, all the living and nonliving factors would make up an ecosystem. So the pond is an
ecosystem. Similar ecosystems around the world make up a biome. There are 8, but the most
important to us, because it is where we live is the deciduous forest, but 2 other examples include
the wettest biome called the rainforest and the driest biome called the desert. The 8 biomes make
up the entire world called the biosphere. The biosphere is made up of 4 major divisions. All the air
on the planet is called the atmosphere. The land is called the lithosphere. All the water on the
planet makes up the hydrosphere. And finally the interactions make up the ecosphere.
As we go through the levels of organization from organism to biosphere, we get into the study of
interactions between organisms and their environment called ecology, in which focus is placed upon
the concept that survival relies on the interactions between the non living factors called abiotic
factors such as the sun, and the living factors called biotic factors, such as waste from an
organism. This concept of survival is called interdependence where inter means between and
dependence indicates a reliance leading us back to a reliance between organisms and their
environment which is ECOLOGY!