1. Copyright 2010. PEER.tamu.edu

2. 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?

3. How is a mall organized? Food Court Big Department Stores
Specialty Clothing Stores
Jewelry Stores
Electronics Stores
Shoe Stores
Toy Stores
Kiosks

4. 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?

5. 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.

6. What is classification?
Classification: putting things into orderly groups based on similar characteristics
Taxonomy: the science of describing, naming, and classifying organisms

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

8. Scientists also Classify Living Organisms
Cats, dogs, mammals, pets, friends………
How could you classify these living things?

9. Quick, organize these living things into groups:

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

11. 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?

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

13. 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

14. Scientific Names Examples
Scientific names can tell you a something about the organism: its size, where it is found, color, who discovered it
EXAMPLES:
Acer rubrum Red maple
Felis domesticus house cat
Lepus californicus Jack rabbit (that lives in CA)
Sequoia gigantea Giant sequoia tree
Strigiphilus garylarsoni Chewing louse found on owls
named after a famous cartoonist

16. Same Genus Different Species
Felis domesticus
Lepus americanus
Felis concolour
Lepus californicus

17. Acer rubrum
Red Maple
Acer saccharinum
Silver Maple

18. Modern Taxonomy The Evidence used to classify into taxon groups
  1) Embryology
  2) Chromosomes / DNA
  3) Biochemistry
  4) Physiology
  5) Evolution
  6) Behavior

20. How to remember?? DOMAIN KINGDOM PHYLUM CLASS ORDER FAMILY GENUS
DASHING
KING
PHILIP
CAME
OVER
FOR
GREAT
SPAGHETTI
DOMAIN
KINGDOM
PHYLUM
CLASS
ORDER
FAMILY
GENUS
SPECIES

21. The most basic classification system is based on Domains and Kingdoms
The most basic classification system is based on Domains and Kingdoms. Organisms are classified into Domains or Kingdoms based on these characteristics:
1. Whether they are unicellular or multicellular 2. Whether they are prokaryotic or eukaryotic (See pg. 8O) 3. Whether they have a cell wall or cell membrane 4. Whether they have membrane bound organelles 5. Whether they are autotrophic or heterotrophic 6. Whether they reproduce sexually or asexually 7. How they tolerate heat, salt, or other extreme conditions
See Vocabulary Activity in this Module.

22. Nucleus and Organelles
Terminology:
prokaryotes - lack membrane bound nuclei and membrane-bound organelles.
Nucleus and Organelles

23. Terminology:
eukaryotes – have a membrane bound nucleus and membrane-bound organelles.

24. 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

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

26. “Archaea” means “ancient” bacteria. Organisms in Archaea are:
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

27. 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.

28. Domain Eubacteria “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.

29. 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.

30. 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

31. 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

32. 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

33. Classification of Living Things
Are Viruses Alive?
Are Prions Alive?

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

35. 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

36. 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

37. 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.

38. Using the Classification System
Field guides help identify organisms.
-they highlight differences between similar organisms (like trees)
Taxonomic Key (Dichotomous Key)
-paired statements that describe the physical characteristics of different organisms

39. Dichotomous Key
1a Fruits occur singly Go to 3
1b Fruits occur in clusters of two or more Go to 2
2a Fruits are round Grapes
2b Fruits are elongate Bananas
3a Thick skin that separates easily from flesh Oranges
3b Thin skin that adheres to flesh Go to 4
4a More than one seed per fruit Apples
4b One seed per fruit Go to 5
5a Skin covered with fuzz Peaches
5b Skin smooth, without fuzz Plums

40. 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?