Biological Foundations 112, Lecture 20


The Classification of Living Things

Chapter 1, pages 11-12
Chapter 20, pages 400-401
Chapter 23, pages 469-471
Five Kingdoms-1 0:00-17:08


I.   The History of Taxonomy

     A.   Theophrastus - 300 B.C. - Greek

            1.   Scientific writings in botany begin here

            2.   Theophrastus was a student of Aristotle

            3.   He described and classified about 500 different kinds of plants

            4.   Used characteristics such as habitat, length of life, flower form, and ovary position as                         a basis for his classification

     B.   Otto Drunfels - 1500 A.D. - German

            1.   Expanded list of known plants

            2.   Made drawing of each plant and coupled it with a description of the plant

            3.   The drawings and descriptions were compiled into books called herbals

            4.   Usually contained mostly:

                  a.   Herbaceous plants

                  b.   Plants useful for medicinal purposes

                  c.   If part of the plant imitates the shape of a human body organ, that plant part was
                        used for the correcting the ailment of that body organ

     C.   Carlos Linneus - 1753 A.D. - Swedish

            1.   Systematized both plants and animals

            2.   1753 - published Species Plantarum

                   a.   Contained 1,000 genera

                   b.   Contained 6,000 species

            3.    Name given to the plant in his system:

                   a.   Polynomial - 12 word Latin description of the plant

                   b.   Binomial - the first two Latin words of the polynomial was the scientific
                                            name of the plant

                         (1)  Consists of the genus and species name

                         (2)  The genus is like our surname

                         (3)  The species is like our first name

                         (4)  The genus name is always written first and capitalized

                         (5)  The species name is always written second and never capitalized

                         (6)  Thus if you were to write your name "scientifically" it would be written as  
                                Doe John rather than John Doe

                   c.   Later biologists standardized on the binomial as THE SCIENTIFIC NAME

                   d.   Examples:

                         (1)  Canis lupus - the wolf

                         (2)  Canis latrans - the coyote

II.  How Plants and Animals are Classified

      A.   Well over 1 million species of living organisms world wide

      B.   Definition of a species

             1.   Groups of morphologically and ecologically similar organisms that interbreed

             2.   See the definition of species on page 437 in your book

      C.   Classification levels

                Kingdom

                   Division

                      Class

                         Order

                            Family

                              Genus

                                 Species

                                   Subspecies

                                     Variety

                                        Strain

      D.   All classification is based on similarities and differences

             1.   Closely related organisms are quite similar and have relatively few differences and
                   many similarities

             2.   Distantly related organisms are quite dissimilar and have relative few similarities  
                   and many differences

      E.   Taxonomic terms

             1.   Taxonomy - involves three specific areas

                   a.   Classification - the grouping of organisms in some hierarchical order

                   b.   Nomenclature (naming) - naming of the group of organisms according to a        
                         universally accepted set of rules

                   c.   Identification - selection and use of a group of unique characters for    
                                                  distinguishing one taxonomic group from another (usually by the
                                                   use of a dichotomous key)

             2.   Flora - all the plants living in a given geographic region

             3.   Fauna - all the animals living in a given geographic region

III. Kingdoms of Organisms

      A.   Most biologists recognize 5 kingdoms

      B.   The five kingdoms are as follows:

            1.   Plantae - plants

            2.   Animalia - animals

            3.   Fungi - mushrooms, molds, and mildews

            4.   Protista - all single-celled organisms such as algae, slime molds, and amoeba

            5.   Monera - all the organisms that do not contain organelles in their cells such as the  
                                   bacteria and cyanobacteria

IV. Domains

      A.   One taxonomic level above Kingdoms has been proposed by some biologists called a    
             Domain with two different Domains being suggested

      B.   The two Domains are as follows:

             1.   Prokaryota

                   a.   Includes the bacteria and cyanobacteria

                   b.   Cells lack a nucleus and contain no organelles such as mitochondria,    
                         chloroplasts, and lysosomes

                   c.   Means "before nucleus" in Greek

             2.   Eukaryota

                   a.   Means "true nucleus" in Greek

                   b.   Cells contain a nucleus and membrane-bounded organelles

                   c.   Includes all other organisms that are not bacteria or cyanobacteria


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