1. Class Notes 2: Classification

2. Classification A. Organisms can be classified based on physical similarities.
B. Linnaeus developed the scientific naming system still used today.
Taxonomy is the science of naming and classifying organisms.
White oak: Quercus alba

3. C. Binomial nomenclature is a two-part scientific naming system.
1. uses Latin words
2. scientific names always written in italics
3. two parts are the genus name and species descriptor

4. D. A genus includes one or more physically similar species.
1. Species in the same genus are thought to be closely related.
2. Genus name is always capitalized.
E. A species descriptor is the second part of a scientific name.
1. always lowercase
2. always follows genus name; never written alone
Tyto alba

5. II. Linnaeus’ classification system has seven levels.
A. Kingdom, phylum, class, order, family, genus, species.
B. Levels get increasingly specific from kingdom to species.

6. III. Cladistics
The Linneaen system of classification only uses physical similarites.
Modern classification is called cladistics and is based on evolutionary evidence:
1. Fossil Records
2. DNA similarities

7. IV. Cladograms
A cladogram is an evolutionary tree that groups organisms together by common ancestry.
A clade is a group of species that shares a common ancestor.

8. V. Kingdoms
A. Classification has changed over time. B. Until 1866, only two kingdoms- animalia and plantae existed. C. Over time, the kingdoms protista, fungi, archae, and bacteria were added.

9. IV. Domains
A. Domains are above (more general than) the kingdom level.
Proposed by Carl Woese based on rRNA studies of prokaryotes
The three domains are Bacteria, Archae, and Eukarya

10. B. Domain Bacteria includes prokaryotes in the kingdom Bacteria.
1. one of largest groups on Earth
2. classified by shape, need for oxygen, and diseases caused

11. C. Domain Archaea includes prokaryotes in the kingdom Archaea.
1. cell walls chemically different from bacteria
2. differences discovered by studying RNA
3. known for living in extreme environments

12. D. Domain Eukarya includes all eukaryotes.
1. kingdom Protista

13. D. Domain Eukarya includes all eukaryotes.
1. kingdom Protista
2. kingdom Plantae

14. D. Domain Eukarya includes all eukaryotes.
1. kingdom Protista
2. kingdom Plantae
3. kingdom Fungi

15. D. Domain Eukarya includes all eukaryotes.
1. kingdom Protista
2. kingdom Plantae
3. kingdom Fungi
4. kingdom Animalia

16. Summary
What are the 2 parts in binomial nomenclature? What are the 7 levels of Linnaean nomenclature? What is the most general? What is the most specific?