In order to understand the world in which we live, we need to understand the whole picture, from the smallest component of matter and energy to the largest of complex networks that we as homo sapiens (humans) are a part of.
Atoms - These are the basic building blocks for all forms of matter and although they can be further reduced, we will consider them our smallest piece of the puzzle. There are 117 different kinds of atoms or elements that are categorized in the periodic table of elements. When mixed together with themselves or in combinations, they make up compounds and molecules. For example, if you mix the atom oxygen (symbolized as an “O”) with two atoms of hydrogen (symbolized as an “H”), you get water or H2O.
Cells - These compounds and molecules are organized in amazingly complex structures in all things of our universe, including ourselves. For example, the molecule sugar is used as energy in our bodies. Protein molecules provide many functions including structural support, enzymes and movement. Fats, sugars, proteins and many other compounds and molecules make up cells, the basic unit of life as we know it.
Living things can be made up of just one cell such as an amoeba or a great number such as a human. Although impossible to count, it is estimated that a person is made up of over one hundred trillion cells!
Tissues - In complex organisms such as people, there are many different types of cells that perform different functions. For example, blood cells help carry oxygen to other cells. Bone cells make hard deposits that, in combination with other cells, make bones to support our bodies. Muscle cells are designed to expand and contract to produce movement. However, an individual muscle cell isn’t strong enough to help an entire person move. Instead, these cells are organized into tissues of the same type that allow for functionality on a larger scale.
Some organisms, however, only consist of one cell or one cell type in a group and do not have tissues such as bacteria, blue-green algae and simple fungi.
Organs - Just as tissues are organized cells to produce a function, complex organisms such as humans have organs that have specific functions made up of one or more tissues, which are of course, made up of cell types. Examples are the lungs, which bring oxygen into our bodies from the atmosphere, or stomach, which helps us digest the food and drink we consume and our kidneys, which help us remove toxins and wastes from our blood stream.
Organisms - Finally, combine the organs made up of tissues made up of cells made up of molecules made up of atoms together, and you get organisms or an individual life form!
There are obviously a great number of different kinds of organisms occupying our world. Everything from bees, humans, wolves, E.coli, whales, pine trees, bread mold, wheat, moss; all are organisms living in our world. It is estimated that there are over 50 million different kind of organisms occupying this planet, and that’s not even considering the bacteria and viruses! They vary in size from something you would need a powerful microscope to see to the giant sequoia tree standing over 83.3 meters in height. We call this great variation in life biodiversity.
But the complexity doesn’t stop there by any means. We next need to consider that there are more of one type of organism on the planet and how do these organisms interact with their surroundings?
Population - A group of the same kind of organisms living in a particular area is called a population. Often one will hear of population to describe human settlements but it can also be used to describe populations of plants and animals.
Community - Though usually thought of as an area within a human population, community can be used to describe the interaction between different populations within a certain area. These interactions can be simple coexistence, where one population does not significantly impact the other, to specific types of relationships such as predator-prey ones seen with hawks and mice or symbiotic relationships such as bees and flowers that are dependent on each other.
Ecosystem - And finally, how these communities of organisms interact with their environment or surroundings of matter and energy describes an ecosystem. There are different types of ecosystems including boreal forest, tropical forest, prairie (such as here in Southern Alberta) aquatic (fresh water), marine (sea or salt water), arctic, and even urban (cities). For example, an artic hare is white to blend in with its surroundings and is furry to protect itself from the chilling cold of its habitat. A tuna fish has gills to breathe under water and fins to swim quickly through the ocean. A giraffe has a long neck so that it may reach the leaves on the tall branches.
The different interactions organisms have with their environment in an ecosystem are as diverse as the species in which inhabit the planet. Unfortunately, humans sometimes forget that they too are a part of this ecosystem and are responsible for ensuring its health and well being. We are made up of the same materials as our world around us. If we damage or pollute the areas in which we live and air in which we breathe, ultimately it is we who will suffer the consequences.