1. Unit #3 Classification Part 2

2. Dichotomous Keys Useful tool/chart.
We use dichotomous keys to help you identify organisms in the natural world that we don’t know.
We can take an organism and identify it by looking at its characteristics.
These keys always start with 1A, and 1B.
Always start at the top of the key and do what it says.
Go to the right and work down.

3. Dichotomous Keys

5. Evolutionary Classification
Phylogeny –the evolutionary relationship among organisms.
Scientists now group organisms into categories that represent lines of evolutionary descent or phylogeny, not just physical similarities.
This strategy is called evolutionary classification.

6. Evolutionary Classification: How do scientists decide?
Which similarities are most important?
Phylogeny
Cladograms
Similarities in DNA & RNA
Molecular Clocks-a model that uses DNA comparisons to estimate the length of time that two species have been evolving independently. Provide clues to evolutionary history.

7. Cladograms A diagram that shows the evolutionary relationship
among a group of organisms
Useful tools that help scientists
understand how one lineage
branched from another in the
course of evolution

8. Cladograms

9. Cladograms

10. Cladograms

11. Cladograms

12. Cladograms

13. http://faculty. uca. edu/johnc/phylogenyclad1441
Derived Characteristics: Characteristics that appear in the recent parts of the lineage

14. Classification

15. The Three-Domain System
Today we added….
Domain- a large group that is a more inclusive category then any other, even larger than a kingdom. Scientists currently believe this is the most updated system to use. As they make updates, it could change.

16. Remember: Domains are the broadest level of classification.
Archaea and Bacteria contain all prokaryotes which are thought to be the earliest forms of life on Earth.
Eukarya contains all eukaryotic organisms .

17. The Three-Domain System
1. Archaea – Prokaryotes, which corresponds to the Archaebacteria which is old/ancient or gas type bacteria.
2. Bacteria – Prokaryotes, are Eubacteria which is true bacteria. Has 3 common shapes.
3. Eukarya – are Eukaryotes which are
composed of protists, fungi, plants,
and animals.

18. 6 Kingdoms Eubacteria Archaebacteria Fungi Protista Animalia Plantae
NOTE: Viruses are NOT LIVING
so they don’t belong in a
kingdom

19. Eubacteria True bacteria Can be round, rod, or spiral shaped
Are prokaryotes which are simple cells with no nucleus, no organelles like our cells and just ribosomes and a blob of DNA
Have peptidoglycan in their cell walls
Largest kingdom of the prokaryotes.
This kingdom is bigger than all the other kingdoms put together
Are small in size
Used to be in the Monera kingdom
Examples are E. coli, and blue-green bacteria

20. Eubacteria

21. Eubacteria

22. Archaebacteria Are prokaryotes Are very small Are gases
No peptidoglycan in their cell walls
The smaller of the bacteria kingdoms
Live in very harsh environments
Salt lovers and Heat lovers
Used to be in the Monera kingdom
Ancestors of eukaryotes
Examples are the methanogens, halophiles, and thermophiles

23. Archaebacteria

24. Fungi Are heterotrophs, have hyphae(tiny filament)
Feed on dead or decaying organic matter
Secrete digestive enzymes into their food source
Are eukaryotes
Examples are mushrooms , molds(multicellular), and yeast (unicellular)
Used to be in the kingdom Plantae a long time ago

25. Fungi

26. Protista Are eukaryotes, we call them protozoans
Are not classified as animals, plants, or fungi even though they look like them
Have great variety, was a “catch all” kingdom a long time ago
Are mostly single-celled, however some are multicellular
Some are photosynthetic
Can cause disease
Examples are amoeba, paramecium, euglena, diatoms, and dinoflagellates

27. Protista

28. Animalia Are eukaryotes Are multicellular and heterotrophic Backbones!
Invertebrates – 95% to 99%
Vertebrates – 1% to 5%
Animals can move about for all or part of their life- sponge is sessile (doesn’t move)
Incredible diversity
Exist in nearly every part of the planet
Examples are sponges, insects, worms, jellyfish, crabs, HUMANS,and mammals.

29. Animalia

30. Plantae Are eukaryotes Are multicellular Are photosynthetic autotrophs
Make sugar (glucose)
Put a lot of Oxygen into the atmosphere
Are non-motile(not able to move), can grow
Have cell walls that contain cellulose
Examples: mosses, ferns, flowering plants (angiosperms), some algae, shrubs, and trees

31. Plantae

32. Summary of the Six Kingdoms
Eubacteria
Archaebacteria
Protista
Fungi
Plantae
Animalia
Cell Type
Prokaryote
Eukaryote
Number of Cells
Unicellular
Most unicellular; some colonial; some multicellular
Most multicellular; some unicellular
Multicellular
Mode of Nutrition
Autotroph or heterotroph
Heterotroph
Autotroph
Examples
E.Coli
Streptococcus
Methanogens, halophiles
Amoeba, paramecium slime molds, giant kelp
Mushrooms, yeasts
Mosses, ferns, flowering plants
Sponges, worms, insects, fishes, mammals

33. Comparison of the Six Kingdoms
Factors
Archaebacteria
Eubacteria
Protista
Fungi
Plantae
Animalia
Representative Organism
(examples)
Cell Type
(eukaryotic or prokaryotic)
Presence and Type of Cell Wall
Macrostructure
(unicellular or multicellular)
Nutrition (autotrophic or heterotrophic)
Locomotion
(mobile or immobile)
Reproduction
(asexual, sexual,
or both)
Ecological/Economic Importance

34. Let’s Review: Fungi used to be in Plantae Kingdom
Protista was included in the 3 kingdom system a long time ago
Cladistic analysis focuses on the order in which derived characters appear in organisms.
All organisms have DNA and/or RNA to pass on information

35. Review: First term is the genus and is capitalized
Second term is the specie and is lower case
We have only classified a fraction of the organisms on Earth
We mostly use Latin to classify or say they are Lantinized
To study organisms requires the use of both large and small categories

36. Review: Bacteria used to be in the kingdom Monera
There are 7 levels of classification
The main idea behind molecular clocks is that neutral mutations accumulate at a steady rate
Our classification system is numerous and diverse

37. Review:
Before Linnaeus, classification was very long and hard to understand
Protists are very diverse and cannot fit into any other kingdom
We italicize scientific names and some people under-line
For many species there are regional differences in the common names of organisms

38. Review:
Organisms that are not closely related but look similar have convergent evolution
Organisms with cell walls of chitin are in the kingdom Fungi
Our scientific names today are much shorter than in the past

39. Comparison of the Six Kingdoms
Factors
Archaebacteria
Eubacteria
Protista
Fungi
Plantae
Animalia
Representative Organism
(examples)
extremeophiles
Cell Type
(eukaryotic or prokaryotic)
prokaryotic
Presence and Type of Cell Wall
Cell wall present, made of lipids
Macrostructure
(unicellular or multicellular)
unicellular
Nutrition (autotrophic or heterotrophic)
autotrophic (chemosynthesis)
Locomotion
(mobile or immobile)
mobile and immobile
Reproduction
(asexual, sexual,
or both)
asexual only
Ecological/Economic Importance
basis of many food chains (where they could not otherwise be)