1. The Six Kingdoms of Living Things

2. How many different organisms are there on earth?
The latest estimate by scientists is that there are 8.7 million different species on earth!
But, some scientists think this estimate is way too low.
The truth is we really don’t know, but we do know there are millions of different species.

3. That is why we classify.
Because there are so many different kinds of living things, scientists have classified them and grouped them by their characteristics. This makes it easier to study them. Every living thing belongs to one of the six kingdoms of living things.

4. The Six Kingdoms Archaebacteria Eubacteria Protista Fungi Plantae
Animalia

5. Three characteristics determine how to classify an organism into a kingdom.

6. 1. How many cells make up the body of the organism?
An organism that is made up of only one cell is called a UNICELLULAR organism.
An organism which is made up of more than one cell is called a MULTICELLULAR organism.

7. 2. Does the organism have a nucleus?
An organism that has a nucleus is called a EUKARYOTE.
An organism that does not have a nucleus is called a PROKARYOTE.

8. 3. How does the organism get its food?
Organisms which make their own food are called AUTOTROPHIC.
Organisms that must take in food are called HETEROTROPHIC.

9. Archaebacteria Archaebacteria are unicellular. They are prokaryotes.
Some are autotrophic and some are heterotrophic.
They are often found in extreme conditions, such as hot springs.

13. Eubacteria Eubacteria are unicellular. They are prokaryotes.
Some are autotrophic and some are heterotrophic.
This is the larger of the two bacteria kingdoms and they don’t live in extreme conditions.

17. Protists Some protists are unicellular and some are multicellular.
All protists are eukaryotes.
Some of them are autotrophic and some are heterotrophic
They are divided into three groups-plantlike, animal-like, and funguslike. This is the odds-and-ends kingdom.

21. Fungi
Most fungi are multicelluar. One exception is yeast. Yeast are unicellular.
All fungi are eukaryotes.
All fungi are heterotrophic.
Fungi are important sources of food (yeast and mushrooms) and they help recycle Earth’s wastes (decomposers).

25. Plants All plants are multicellular. All plants are eukaryotes.
All plants are autotrophic.
Plants produce food and oxygen, which are required by most organisms on Earth.

29. Animals All animals are multicellular. All animals are eukaryotes.
All animals are heterotrophic.
Animals provide food and companionship in your daily lives.