Taxonomy• The study of the

classification of living things• Taxa – group of one or

more groups of organisms • SIX hierarchical levels of

classification1. Domain EUKARYA2. Kingdom ANIMAL3. Phylum CHORDATA4. Class

MAMMALIA5. Order PRIMATES6. Family HOMINIDAE7. Genus HOMO8. Species SAPIENS

Increasing similarity

Most Inclusive

Increasing diversity

Least Inclusive

Binomial Nomenclature• Carolus Linnaeus

(1700’s)• System for

naming and classifying species

• Two characteristics1. Genus 2. Species

• Used by all countries in all languages to avoid confusion among scientists.– Homo sapiens– Canus lupus– Felis

domesticus

Proper Way of Naming • Three ways to properly

name and classify an organism

1. All Italics - capital letter of first name followed by lower case letter Tamiasciurus hudsonicus

2. Italics - capital letter followed by period (.) and then lower case letter italics T. hudsonicus

1. Handwritten - always underline the name Tamiasciurus hudsonicus

Common Name Family Scientific Name

Red squirrel Sciuridae Tamiasciurus hudsonicus

Short-tail weasel Mustelidae Mustela erminea

Groundhog Sciuridae Marnota monax

Mink Mustelidae Mustela vison

Eastern chipmunk Sciuridae Tamias striatus

River otter Mustelidae Lutra canadensis

Fisher Mustelidae Martes pennanti

Muskrat Cricetidae Ondatra zibethica

Black-footed ferret Mustelidae Mustela nigripes

Group organisms with increasing similarities

Dichotomous Key• Tool used by biologists to

identify an unknown organism• Series of paired statements of

anatomical description that leads to an identification.

Key for Vertebrate Identification1. a) animal has a spine…………………..go to 2

b) animal has no spine………..…invertebrate2. a) animal has no gills and fins……..…. go to 3 b) animal has gills and fins…………….. Fish3. a) animal has no scales…………..........go to 4 b) animal has scales………………..….reptile4. a) animal has feathers …………………..bird b) animal has no feathers ……………..go to 55. a) animal has hair…………………….mammal b) animal has no hair………………..amphibian

Three Domain Classification System• Based on

– DNA analysis, Evolutionary history, Relationship among organisms

Include 1. Bacteria (Prokaryotes)

A. Gram positive bacteria B. Spirochetes C. Chlamydia D. Cyanobacteria

2. Archaea (Prokaryotes)A. ExtremeophilesB. HalophilesC. Methanogens D. Thermophiles

3. Eukarya (Eukaryotes) A. Protista B. FungiC. Plants D. Animals

Major Features of The Three Domains

Bacteria, Acrchaea, and Eukaryotes

Feature Bacteria Archaea Eukaryotes

Membrane-enclosed organelles Absent Absent Present

Peptidoglycan in cell wall Present Absent Absent

RNA polymerase One Type Several Kinds Several Kinds

Introns (noncoding regions of genes) Absent Present in some genes

Present

Antibiotic sensitivity to streptomycin, chloramphenicol

Inhibited Not inhibited Not inhibited

Domain Bacteria• Lacks a nucleus and other

membrane bound organelles• Contain ribosomes• Pili – hair like structures used

to attach to other cells or objects

• Flagellum – tail like extension for motorboating (propeller)

• Cell wall • Nucleoid – chromosomal DNA• Plasmids – small circular pieces

of DNA• Capsule – composed of

polysaccharides, protects cell against phagocytosis

Bacteria are Pathogens• Klebsiella pneumoniae• Clostridium difficile• Escherichia coli• Staphylococcus aureus– MRSA

• Streptococcus pyogenes– Flesh eating disease

Common Shapes of Prokaryotes • Coccus (Round)– N. meningitidis – meningitis

• Bacillus (Rod)– B. anthracis - anthrax

• Diplococci (Pair)– N. gonorrhoea – gonorrhoea

• Streptococci (Chain)– S. pyogenes – scarlet fever

• Spirochete (Spiral)– T. pallidum – syphilis

• Cell walls are composed of peptidoglycan • Reproduce Asexually via binary fission• Make energy using organic chemicals, inorganic chemicals, or

photosynthesis

Bacteria

Archaea• Lack peptidoglycan in cell wall• Reproduce via Binary Fission• Live in extreme environments• Methanogens– Live in environments that lack

oxygen – Produce methane gas– Live in landfills

• Extreme halophiles– Live in environments that love

salt – Dead Sea, Great Salt Lake

• Extreme thermophiles– Live in environments of extreme

heat – Volcanic vents deep in the ocean

Binary Fission• Asexual

Reproduction

Conjugation• Transfer of

genetic material between bacterial cells

• Creates genetic diversity

• Antibiotic resistance

Domain Eukarya • Protista• Fungi• Plantae• Animalia

Animal-like Protists• Sporozoans– Cannot move on their own

(nonmotile)– Reproduce both sexually

(gametes) and asexually (mitosis)

– Parasites – Transmitted through vectors

(insects)

• Plasmodium vivax– Causes malaria (most common) – Transmitted by female

anopholes (mosquito)

Plasmodium vivax • Mosquito bites– Infects human with

sporozoites• Sporozoites infect liver

cells– Develop into merozoites

• Merozoites infect RBC’s– Continue to infect RBC’s – Some develop into

gametocytes • Mosquito bites infected

human– Gametocytes fertilize,

develop into oocyst• Oocyst ruptures

releasing sporozoites

• Eukaryotes• Cellulose cell walls• Use photosynthesis for

energy (primary producers)

• Produce molecular oxygen and organic compounds

Plant-like Protists (Algae)

Plant-like protists • Dinoflagellates– Marine plankton (flagella)– Red tide

• Algal blooms produce dinotoxins • Toxic to humans

• Diatoms – Phytoplankton– Cell wall is made up silica

• Euglenoids – Contain chloroplasts – Also feed by phagocytosis

• Green Algae – Macroscopic seaweeds

• Eukaryotes • Chitin cell walls• Use organic chemicals for energy

(consumers/heterotrophs)• Decomposers (important in

ecosystems)• Moulds – consist of masses of mycelia,

which are composed of filaments called hyphae

– Reproduce asexually (spores) • Yeasts – Round shape – Reproduce asexually (budding)

Fungi

Yeast Reproduction• BuddingNew organism

develops from outgrowth on another cell at a particular site

• Ascus Spore bearing

cell in fungi

Plantae (Eukaryotes)• All are autotrophic (make own food)– Synthesizing organic molecules using photosynthesis– Immobile

• 10 divisions of plants • Characteristics of Plants include– Vascular tissue– Cone bearing– Flowering – Mosses, – Ferns

Animalia (Eukaryotes)• All are Heterotrophic • Multicelluar • Grouped into 35 phyla• Most reproduce

sexually (diploid stage)• Most species – sperm

fertilizes egg• Monophyletic– All animal lineages

can be traced back to a single common ancestor

– Classified by anatomical features

Classification of Animalia• Organisms are

classified and identified using 6 characteristics

1. Structural – anatomy and physiology

2. Biochemical – enzymes, proteins, DNA

3. Cytological – cell structure

4. Embryological– development

5. Behavioral – patterns of actions

6. Fossil – common ancestor