1. Copyright 2010. PEER.tamu.edu

2. Classification of Living Things

3. Why do we classify things?
Supermarket aisles
Libraries
Classes
Teams/sports
Members of a family
Roads
Cities
Money

4. Why classify things? Say you go to the mall to get some new clothes.
Where would you go?
How would you know to go to that particular store?

5. How is a mall organized? Food Court Specialty Clothing Stores
Jewelry Stores
Electronics Stores
Shoe Stores
Toy Stores

6. Can you imagine if the mall was just one big store and you had to go through rows and rows of “stuff” to find the right clothes in the right brand and the right size for you?
How long would that take?

7. Big Idea:
The mall, your city, your school, and your closet (hopefully) are all organized so that you and other people can get things done without wasting extra time and effort.
Scientists also organize or classify things so that they are easier to investigate and understand.

8. Here are some things that scientists classify or organize:
The elements
The human body
Interactions in Ecosystems

9. Early classification Aristotle grouped everything into
simple groups such as animals or plants
He then grouped animals according to if they had blood or didn’t have blood, and if they had live young or laid eggs, and so on…

10. Binomial Nomenclature
Developed by Carolus Linnaeus
Swedish Biologist 1700’s
Two-name system
Genus and species named using Latin or Greek words

11. Rules used to write scientific names
Homo sapiens
An organism’s genus is always written first; the organism’s species is always written second
The genus is Capitalized; the species is
written in lower case
Scientific names of organisms are always italicized or underlined

12. The modern system of classification has 8 levels:
Order
Family
Genus
Species
Domain
Kingdom
Phylum
Class

14. Basic Classification Domains:
Archaea
There are three Domains of living organisms based on their characteristics:
Archaea (also called Archaebacteria)
Eubacteria (also called Bacteria)
Eukaryota (also called Eukarya)
Eubacteria
Eukaryota

15. Basic Classification Kingdoms:
The Domains can also be split into Kingdoms which further divide the organisms by their characteristics.

16. Autotrophic or heterotrophic
Domain Archaea
Aerial view of hot spring at Yellowstone
“Archaea” means “ancient” bacteria.
Organisms in Archaea are:
Unicellular
Prokaryotic
Autotrophic or heterotrophic
Organisms that reproduce asexually
Bacteria that have adapted to extreme environments.
Some can survive in extremely hot environments, like around hot springs and geysers. They are called thermophiles.
Some can survive in extremely salty environments, like The Great Salt Lake in Utah. They are called halophiles.
The Domain Archaea has one Kingdom, also called Archaea

17. This hot spring is flowing into the Firehole River in Yellowstone
This hot spring is flowing into the Firehole River in Yellowstone. The colors are caused by different varieties of archaebacteria and other microscopic life forms. Scientists can distinguish temperatures of water by the colors present.

18. Domain Eubacteria Many are common infectious agents.
“Eu” means “true” bacteria. They are:
Unicellular
Prokaryotic
Autotrophic or heterotrophic
Organisms that reproduce asexually
The most abundant organisms on earth. One bacterium can give rise to 10 million in 24 hours.
Found in almost every habitat on earth.
The Domain Eubacteria has one Kingdom, also called Eubacteria.
Many are common infectious agents.

19. This is a picture of bacteria on the skin
This is a picture of bacteria on the skin. Bacteria can be shaped like a sphere (cocci) like this picture, like a rod, or like a spiral. The structure in the middle of this picture is a hair follicle with a hair growing out of it.

20. Nucleus and Organelles
Terminology:
The Domains Archaea and Eubacteria are commonly grouped together in discussion and called
prokaryotes because they lack membrane-bound nuclei and membrane-bound organelles.
Nucleus and Organelles

21. Domain Eukaryota (Eukarya)
Eukaryotic
Very diverse
Unicellular or multicellular
Autotrophic or heterotrophic
Reproduce sexually or asexually
Can be split into 4 Kingdoms-
Protista
Fungi
Plantae
Animalia

22. The 4 Kingdoms in Eukaryota
Protista
Mostly unicellular and microscopic
Autotrophic or heterotrophic
Can be infectious agents
Examples:
Amoeba
Algae
Daphnia
Plasmodium (causes malaria)
Plantae
Multicellular green plants
Autotrophic through photosynthesis
Have a cell wall
Mosses
Ferns
Trees
Flowering Plants
Fungi
Multicellular
Heterotrophic
Decomposers
Mushrooms
Athlete’s foot
Bread Mold
Animalia
Multicellular Animals
No Cell Wall
Insects
Spiders
Crabs
Birds
Humans

23. D O M A I N S K I N G D O M S

24. Think Break: Where do Viruses fit in this classification system?
Are Viruses Alive?
Are Prions Alive?

25. How would you classify these?
A organism that can exist in extremely hot temperatures and that is made of only one cell with no nucleus Domain: Archaea Kingdom: Archaea A green organism growing from the ground that is multicellular and that undergoes photosynthesis; its cells have nuclei and cell walls Domain: Eukaryota Kingdom: Plantae

26. Try two more:
This microscopic and one-celled organism lives in colonies with millions of others like it. It does not have a nucleus and cannot survive in extreme conditions. It could be an infectious agent. Domain: Eubacteria Kingdom: Eubacteria This organism is a multicellular decomposer; its cells have nuclei. Domain: Eukaryota Kingdom: Fungi

27. Classification Systems Can Change! Can you guess why?
Classification systems change as new organisms are discovered and as more information is gained about known living organisms.
Science is a “work in progress” and things change as new evidence is found.
There is a great amount of debate over the current classification system, especially the classification of the types of bacteria and whether viruses are alive or not.

28. Which one would you choose? Why?
Even though classification is not an exact science, it is a part of almost every aspect of our lives.
This is an example of classifying by personal preference which all students have experience with.
Which one would you choose? Why?

29. Quick, organize these living things into groups:

30. Did you do it like this? These are grouped by color:
Blue, red or red and blue

31. Are there any other ways to group these living things?
Or this?
These are grouped by type of organisms: Fish, butterfly or bird
This is probably a more meaningful way to group these for scientific purposes than the previous slide’s grouping by color.
Are there any other ways to group these living things?

32. Classify these organisms