Unit 13Unit 13

Classification of Classification of OrganismsOrganisms

I. Isn’t everything living I. Isn’t everything living thing either a plant or an thing either a plant or an

animal?animal?A. AristotleA. Aristotle is is

credited with the first credited with the first true true classification system. He classification system. He

grouped all living things into grouped all living things into two two basic groups: basic groups: plant plant

and animaland animal..

OR

B LinnaeusB Linnaeus further classified further classified plants and animals by dividing plants and animals by dividing them into related groups. He them into related groups. He used the used the LatinLatin language, language, because Latin was not longer because Latin was not longer spoken conversationally and spoken conversationally and thus was less likely to change.thus was less likely to change.

1. He first grouped related 1. He first grouped related organisms. He called this a organisms. He called this a genusgenus. For example, all of . For example, all of the dog-like creatures were the dog-like creatures were grouped as the genus grouped as the genus CanisCanis..

2. He next gave every different type 2. He next gave every different type of organism in the group a of organism in the group a specific name, which he called specific name, which he called speciespecie. For example, the dog . For example, the dog becamebecame

Canis familiarisCanis familiaris and the wolf and the wolf

Canis lupusCanis lupus. Notice the . Notice the genus is genus is capitalizedcapitalized but the but the specie begins specie begins with a lower case letterwith a lower case letter! !

Both are Both are italicizeditalicized or underlined. or underlined.

3. Thus, every organism was 3. Thus, every organism was given a two-word name, the given a two-word name, the genus and speciegenus and specie. This . This practice of practice of binomial binomial nomenclature nomenclature continues continues today, giving each organism a today, giving each organism a ““scientific namescientific name”.”.

4. The benefit of binomial 4. The benefit of binomial nomenclature includes nomenclature includes eliminating confusion due to eliminating confusion due to common namescommon names (ex. (ex. cottonmouth and water cottonmouth and water moccasin are actually the moccasin are actually the same animal) and allows same animal) and allows scientists around the world to scientists around the world to more easily communicate.more easily communicate.

What name do you use for this organism?

Loxosceles reclusa (Brown Recluse)

C. Even after the C. Even after the microbialmicrobial world world was discovered, was discovered, the two the two “kingdom” “kingdom” system continued. system continued. (Yes, science can (Yes, science can be very slow to be very slow to change.)change.)

D. As knowledge of D. As knowledge of the diversity of the diversity of organisms organisms increased, increased, WhittakerWhittaker (in (in 1969) expanded 1969) expanded classification to classification to include include fivefive kingdoms.kingdoms.

E. The science of classification, E. The science of classification, taxonomytaxonomy, now allowed , now allowed scientists to assign scientists to assign seven levels seven levels of taxaof taxa to living organisms: to living organisms:

Kings

Play

Cards

On

Fat

Green

Stools

1. The 1. The kingdomkingdom is the most is the most general of these seven taxa, general of these seven taxa, thus the kingdom would contain thus the kingdom would contain the greatest number of the greatest number of organisms.organisms.

2. 2. SpecieSpecie is the most specific of is the most specific of these seven taxa, thus the these seven taxa, thus the specie would contain only one specie would contain only one type of organism. A specie is type of organism. A specie is defined as a defined as a group of organisms group of organisms which can interbreed and which can interbreed and produce fertile offspringproduce fertile offspring..

F. Today, we use F. Today, we use three domainsthree domains, , which are divided into which are divided into six six kingdomskingdoms. These domains are . These domains are based on new information about based on new information about possible evolutionary possible evolutionary relationshipsrelationships..

II. What happens when you II. What happens when you find an organism and you find an organism and you are stymied?are stymied?

A. A. Dichotomous keysDichotomous keys are tools that use a are tools that use a series of paired statements and the series of paired statements and the visible characteristics of the organism. visible characteristics of the organism. Of course, a dichotomous key is only Of course, a dichotomous key is only useful if the organism has already useful if the organism has already beenbeen classified and given a scientific classified and given a scientific namename..

1. Always 1. Always start at statement 1start at statement 1 (or the (or the beginning point)beginning point)

2. Decide which path best 2. Decide which path best describes describes the organismthe organism (Statement A or (Statement A or Statement B)Statement B)

3. Follow that path3. Follow that path to find the next to find the next choice (Go to …)choice (Go to …)

4. When you can go no further, you 4. When you can go no further, you will will find the namefind the name!!

B. If the organism has NOT been B. If the organism has NOT been classified, taxonomists must begin the classified, taxonomists must begin the process of classification. In order to process of classification. In order to correctly classify an organism, correctly classify an organism, scientists use many modern tools:scientists use many modern tools:

1. 1. MorphologyMorphology describes the physical describes the physical characteristics of an organism. characteristics of an organism. Typically, this is enough information Typically, this is enough information to place the organism within a domain to place the organism within a domain and kingdom.and kingdom.

Example: Presence of a nucleus places Example: Presence of a nucleus places the organism in Domain the organism in Domain EukaryaEukarya

2. 2. DNA and biochemical analysisDNA and biochemical analysis allow allow scientists to test less visible, but scientists to test less visible, but distinguishing, characteristics.distinguishing, characteristics.

Example: Gram staining a bacteria cell Example: Gram staining a bacteria cell allows scientists to distinguish allows scientists to distinguish between between archaeaarchaea and and prokarya.prokarya.

Gram-positive anthrax bacteria (purple rods) in cerebrospinal fluid sample. If present, a gram-negative bacterial species would appear pink. (The other cells are white blood cells)

Gram-negative E. Coli bacteria.

3. 3. Comparing embryology Comparing embryology allows allows scientists to group organisms that scientists to group organisms that share common fetal development.share common fetal development.

Example: The diagram below would Example: The diagram below would suggest the suggest the lastlast fourfour organisms are organisms are most closely related.most closely related.

4. 4. Evolutionary phylogeny Evolutionary phylogeny describes the describes the evolutionary relationships between evolutionary relationships between organisms. These relationships are organisms. These relationships are deduced based on deduced based on shared traits shared traits that that may have been passed from ancestor may have been passed from ancestor to new species. Traits may include to new species. Traits may include physical traits physical traits (ex. presence of jaws), (ex. presence of jaws), or may be or may be genetic traitsgenetic traits (shared (shared genes). These relationships can be genes). These relationships can be illustrated in a illustrated in a phylogenetic tree phylogenetic tree or or cladogramcladogram::

1) German Shepherd, Great Dane, parrot, Irish setter,

canary, husky, robin, pigeon

Title_________________ _____________________

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Title_________________ _____________________

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2) apples, peas, orange, banana, carrot, lettuce, turnip,

pear, grape, potato

Title_________________ _____________________

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Title_________________ _____________________

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Review QuestionsReview Questions

1. Who first officially classified 1. Who first officially classified organisms?organisms?

Aristotle, then Linnaeus created our Aristotle, then Linnaeus created our current systemcurrent system

2. What was the contribution of Linneaus 2. What was the contribution of Linneaus to taxonomy?to taxonomy?

He grouped related organisms and He grouped related organisms and created binomial nomenclature (every created binomial nomenclature (every organism has a two word name- genus organism has a two word name- genus and species)and species)

3. What are the two parts of a scientific 3. What are the two parts of a scientific name?name?

Genus and speciesGenus and species

4. What are the domains used in the 4. What are the domains used in the current classification system?current classification system?

Prokarya, Archae, EukaryaProkarya, Archae, Eukarya

Review QuestionsReview Questions

5.5. How many kingdoms are used in the How many kingdoms are used in the current classification system?current classification system?

SixSix

6. What is a dichotomous key?6. What is a dichotomous key?

A key that uses paired statements and A key that uses paired statements and visible characteristics to identify a visible characteristics to identify a known organism.known organism.

7. What 4 modern tools are used to 7. What 4 modern tools are used to classify a newly discovered organism?classify a newly discovered organism?

Morphology, biochemical similarities, Morphology, biochemical similarities, embryology, and phylogeny embryology, and phylogeny (evolutionary relationships)(evolutionary relationships)

III. Why am I not a fungus?III. Why am I not a fungus?A. Kingdom BacteriaA. Kingdom Bacteria

1. Cellular Structure: 1. Cellular Structure: ProkaryoticProkaryotic with with cell wall, cell wall, unicellularunicellular

2. Metabolism:2. Metabolism:

a. Food getting: a. Food getting: Very diverse – Very diverse – some are some are photosyntheticphotosynthetic, some are , some are chemosyntheticchemosynthetic and some are and some are

heterotrophicheterotrophic, , taking in food by taking in food by active active transport.transport.

b. Cellular b. Cellular energy: Some are energy: Some are aerobicaerobic for the production of ATP, for the production of ATP,

some are some are anaerobicanaerobic..

3. Reproduction: Mostly 3. Reproduction: Mostly asexualasexual through through binary fission; may exchange DNA binary fission; may exchange DNA using a process called using a process called conjugationconjugation..

4. Ecological/Economic Importance: 4. Ecological/Economic Importance: Bacteria are important to the Bacteria are important to the environment because they drive the environment because they drive the nitrogen cyclenitrogen cycle and are and are decomposersdecomposers. . Bacteria can be Bacteria can be beneficialbeneficial to humans to humans (ex. useful in making foods such as (ex. useful in making foods such as yogurt) or yogurt) or harmfuharmful (ex. some may l (ex. some may cause disease such as syphilis)cause disease such as syphilis)

WARNING- X-Rated Image of Bacteria Sexually Reproducing

B. Kingdom Archaea (Extreme bacteria!)B. Kingdom Archaea (Extreme bacteria!)

1. Cellular Structure: 1. Cellular Structure: ProkaryoticProkaryotic with with cell wall, cell wall, unicellularunicellular (different (different chemicals in cell wall than Kingdom chemicals in cell wall than Kingdom Bacteria)Bacteria)

2. Metabolism:2. Metabolism:

a.Food getting: Very a.Food getting: Very diverse – some are diverse – some are photosyntheticphotosynthetic, some are , some are chemosyntheticchemosynthetic and some are and some are heterotrophicheterotrophic, taking in food by active , taking in food by active

transport.transport.

b. Cellular energy: b. Cellular energy: Some are Some are aerobicaerobic for for the the production of ATP, some are production of ATP, some are anaerobicanaerobic..

Aerobic = Oxygen used

Anaerobic = No oxygen used

3. Reproduction: Mostly 3. Reproduction: Mostly asexualasexual through through binary fission; may exchange DNA binary fission; may exchange DNA using a process called using a process called conjugationconjugation..

4. Distinguishing habitats: They are all 4. Distinguishing habitats: They are all classified as “classified as “extremophilesextremophiles” – they ” – they live in extreme environments such as live in extreme environments such as thermal vents, swamps, guts of thermal vents, swamps, guts of animals, and areas of high salinityanimals, and areas of high salinity. .

C. Kingdom ProtistaC. Kingdom Protista

1. Cellular Structure: 1. Cellular Structure: EukaryoticEukaryotic (some with cell wall and some (some with cell wall and some without), some arewithout), some are unicellular unicellular (amoeba) and some are (amoeba) and some are multicellularmulticellular (seaweed)(seaweed)

2. Metabolism:2. Metabolism:

a. Food getting: Very a. Food getting: Very diverse – some are diverse – some are photosyntheticphotosynthetic (plant-like), and some are (plant-like), and some are heterotrophicheterotrophic (animal-like), taking in (animal-like), taking in food food by active transport.by active transport.

b. Cellular energy: All b. Cellular energy: All utilize utilize aerobicaerobic respiration for the respiration for the production of ATP.production of ATP.

3. Reproduction: 3. Reproduction: AsexualAsexual through through binary binary fissionfission (in animal-like protists) and (in animal-like protists) and fragmentationfragmentation (in plant-like protists). (in plant-like protists). Some may exchange DNA though Some may exchange DNA though conjugationconjugation (sexual). (sexual).

4. Ecological/Economic Importance:4. Ecological/Economic Importance:

a. Plant-like protists (commonly called a. Plant-like protists (commonly called algaealgae) are the primary producers of ) are the primary producers of oxygenoxygen used for cellular respiration. used for cellular respiration. They are also the They are also the producersproducers that form that form the base of all aquatic food webs. the base of all aquatic food webs.

b. Animal-like protists (commonly called b. Animal-like protists (commonly called protozoansprotozoans) are important ) are important primary primary consumersconsumers in aquatic food webs. in aquatic food webs. Many protozoans also cause diseases Many protozoans also cause diseases such as malaria.such as malaria.

c. A specialized group of protists called c. A specialized group of protists called slime molds slime molds are important are important decomposers. decomposers.

D. Kingdom Plantae D. Kingdom Plantae

1. Cellular Structure: 1. Cellular Structure: EukaryoticEukaryotic with with cell wall, cell wall, all multicellularall multicellular

2. Metabolism:2. Metabolism:

a. Food getting: a. Food getting: All are All are photosyntheticphotosynthetic (autotrophic).(autotrophic).

b. Cellular energy: All b. Cellular energy: All utilize utilize aerobicaerobic respiration for the respiration for the production of ATP.production of ATP.

3. Reproduction: All reproduce 3. Reproduction: All reproduce sexuallysexually (using sperm and egg or (using sperm and egg or spores); may reproduce spores); may reproduce asexuallyasexually (using vegetative propagation or (using vegetative propagation or spores)spores)

Each one of these buds can develop into a new plant next year. In fact a whole row of potato plants can be started from just one good tuber.

4. Ecological/Economic Importance: 4. Ecological/Economic Importance: Plants are Plants are exponentially more exponentially more complex complex as compared to algae, but as compared to algae, but perform many of the same ecological perform many of the same ecological roles (roles (oxygen production, base of food oxygen production, base of food webweb). Plants are also used for ). Plants are also used for numerous productsnumerous products such as clothing such as clothing (cotton), paper, medicine (aspirin), (cotton), paper, medicine (aspirin), and lumber.and lumber.

E. Kingdom Fungi E. Kingdom Fungi

1. Cellular Structure: 1. Cellular Structure: EukaryoticEukaryotic with with cell wall, cell wall, mostly multicellular mostly multicellular (mushroom) with (mushroom) with some unicellularsome unicellular (yeast)(yeast)

2. Metabolism:2. Metabolism:

a. Food getting: a. Food getting: Heterotrophic with Heterotrophic with extracellular extracellular digestiondigestion (fungi secrete (fungi secrete digestive digestive enzymes and absorb nutrients enzymes and absorb nutrients across the cell wall)across the cell wall)

b. Cellular energy: b. Cellular energy: Some utilize Some utilize aerobicaerobic respiration for the production of ATP respiration for the production of ATP

(mushrooms), some (mushrooms), some are are anaerobicanaerobic (yeast).(yeast).

Bird’s Nest Fungi

3. Reproduction: May be 3. Reproduction: May be asexualasexual ((budding in yeast and spore budding in yeast and spore production in other fungiproduction in other fungi), or ), or sexualsexual ((sporespores).s).

4. Ecological/Economic Importance: 4. Ecological/Economic Importance: Fungi are important Fungi are important decomposersdecomposers. . Fungi can be beneficial to humans (ex. Fungi can be beneficial to humans (ex. used to make used to make food and alcoholfood and alcohol), or ), or harmful (harmful (cause diseasescause diseases such as ring such as ring worm and athletes foot)worm and athletes foot)

F. Kingdom Animalia F. Kingdom Animalia

1. Cellular Structure: 1. Cellular Structure: Eukaryotic with Eukaryotic with no cell wallno cell wall, , all are multicellularall are multicellular

2. Metabolism:2. Metabolism:

a. Food getting: All are a. Food getting: All are heterotrophicheterotrophic and have diverse and have diverse methods for acquiring methods for acquiring food.food.

b. Cellular energy: All b. Cellular energy: All utilize utilize aerobicaerobic respiration for the respiration for the production of ATP but production of ATP but some some specialized cells can convert to specialized cells can convert to anaerobicanaerobic respiration when oxygen is respiration when oxygen is

scarcescarce

3. Reproduction: All animals reproduce 3. Reproduction: All animals reproduce sexuallysexually (egg and sperm), but some (egg and sperm), but some simple animals may also reproduce simple animals may also reproduce asexuallyasexually (fragmentation in sponges, (fragmentation in sponges, regeneration in worms)regeneration in worms)

4. Ecological/Economic Importance: 4. Ecological/Economic Importance: Animals are important Animals are important consumersconsumers in in food webs. Animals may be beneficial food webs. Animals may be beneficial to humans (ex. to humans (ex. foodsfoods) or harmful (ex. ) or harmful (ex. worms may cause worms may cause diseasedisease))

Review Questions: Review Questions:

1. Which 2 kingdoms contain bacteria?1. Which 2 kingdoms contain bacteria?

Archaebacteria and EubacteraArchaebacteria and Eubactera

2. Which 2 kingdoms are prokaryotic?2. Which 2 kingdoms are prokaryotic?

Kingdom Bacteria and Kingdom ArchaeKingdom Bacteria and Kingdom Archae

3. The organisms of which kingdom do not have cell 3. The organisms of which kingdom do not have cell walls?walls?

Kingdom animaliaKingdom animalia

4. Name the kingdoms that contain important 4. Name the kingdoms that contain important decomposers. decomposers.

Bacteria and FungiBacteria and Fungi

5. Name the kingdoms that contain producers.5. Name the kingdoms that contain producers.

Plantae and ProtistaPlantae and Protista

6. Why are you not a fungus?6. Why are you not a fungus?

I am not a decomposer, do not get my food I am not a decomposer, do not get my food through extracellular digestion, and do not through extracellular digestion, and do not reproduce asexually!reproduce asexually!