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An organism is a life form, or anything showing signs of life. You, me, and the family dog are all organisms. There are many different types of organisms, some that we can’t even see! Let’s learn about all the different types of organisms and what they do!

How are Organisms Classified?

Organisms get classified into seven different categories. This is determined by shared similar characteristics between the organisms. We call this Taxonomic Classification. The categories are:


Kingdoms are the most basic classification of living things. There are currently five kingdoms that we know of. This is decided by how the organism gets its food, the types of cells in its body, and the number of cells.


Phyla are the next level down from Kingdoms. These look for physical similarities between organisms, suggesting a common ancestor.


You’ve probably heard of these before! Classes are the next level of classification down from phyla. Organisms in the same classes have even more similarities. Some examples are mammals, amphibians, and reptiles.


Orders are a smaller way of grouping than a class, but bigger than a family, genus, or species. Examples of orders are Bats, Beetles, and Frogs. 


Families have even more similarities than orders, classes, or phyla. For example, we are part of the Hominidae family! Different species of animals are in their own families as well.


Genus is a way to describe an organism by its generic (scientific) name. There are very few organisms within the same Genus. So, as a result, there are many different scientific names we use for different animals and plants. The genus of an organism helps to name it!


The species of an organism is as specific as you can get! Because this is the last level of classification between organisms, there are thousands of species out there! We are classified as the Human species, and our pets are cats, dogs, lizards, snakes, and so on.
Different groups of animals.

Across the many taxonomic groups, there are all sorts of animals.

What Was the First Living Organism?

The first living organisms were called prokaryotes. These did not have a cell membrane or a nucleus. They were only made up of one cell. This earned them the name single-celled organisms. They appeared around four billion years ago and are still around today! You can’t see them because they’re so small. But, you can sure feel them when you’re sick! 
Illustration of microscope.

We can only see prokaryotes with a microscope.

The World’s Largest Organism: The Humongous Fungus

The world’s largest organism spans about 2.4 miles across the Blue Mountains in Oregon. It is said to be delicious when cooked. But what could it be? It is a honey fungus! When these fungi meet, they have the ability to fuse together into one. These fungi, in particular, are known for killing trees by banding together and infesting the trees. Awesome, right? I think so.
A mushroom chart.

Different kinds of mushrooms. While some of them are edible, they may not be appetizing.

Other Great Resources:

Classification of Living Things – SoftSchools: http://www.softschools.com/science/biology/classification_of_living_things/
Unicellular Organisms – SimpleWikipedia: https://simple.wikipedia.org/wiki/Unicellular_organism
Bill Nye the Science Guy: 

Written by: Hannah Bertoch.