1. Classification Chapter 17

2. Why classify organisms. currently there are 1
Why classify organisms? currently there are 1.5 million known species of living things

3. Taxonomy
field of science that deals with classifying organisms according to their characteristics and evolutionary history

4. Early scientists had to use common names or scientific descriptions when referring to organisms
common names – used by the people of an area, may not accurately describe an organism, vague, one organism might have several common names
Example: jelly fish, ground squirrel, pine tree,…
scientific descriptions – were long, written in different languages, did not indicate relationships
Example: insect having 3 body segments, 6 legs, 2 pairs of wings, hairy abdomen,….

5. Early Classification Aristotle – 2000 BC
devised a classification system
divided living things into 2 groups….
PLANTS – divided into smaller groups based on their stem structure – herbs, shrubs, trees
ANIMALS – divided into smaller groups based on their habitat – land, air, water

6. Early Classification Linnaeus - 1700’s - naturalist
devised a classification system based on comparative morphology
classification system had 7 taxonomic categories
(called TAXONS)
devised a way to give each organism a unique word name

7. 7 taxonomic categories = taxons
Kingdom – composed of similar phyla or divisions
largest group; most variety
Phylum or Division – composed of similar classes
Class – composed of similar orders
Order – composed of similar families
Family – composed of similar genera
Genus – composed of similar species
Species – composed of structurally similar organisms that naturally interbreed and produce fertile offspring
smallest group; least variety

8. ACRONYM – to help you remember the order of the taxons
kingdom - King
phylum - Phillip
class - Came
order - Over
family - From
genus - Great
species - Spain

9. classification of the American Crow
Kingdom: Animalia
Phylum: Chordata (with backbones)
Class: Aves (birds)
Order: Passeriformes (songbirds)
Family: Corvidae (crows, jays)
Genus: Corvus
Species: brachyrhynchos

10. Binomial Nomenclature
giving an organism a unique 2 word name,
A SCIENTIFIC NAME
consists of two words
Genus – 1st word – capitalized
species – 2nd word – lower case
*written in latin or “latinized”
*underlined or italicized

11. Why Latin? “dead” language is the basis for many of today’s languages
no changes being made
it is not in use today
is the basis for many of today’s languages
assures a unique name for each species

12. Scientific Names may tell you…
geographic location of organism
who discovered it
how the organism looks
Examples:
Linnea borealis
Odocoileus virginianus
Felis domesticus

13. Lasionycteris noctivagans
nocti = nocturnal
vagans = wanderer
nyct = night
“wanderer at night”
Silver-haired bat

14. Dichotomous Key “dividing into two parts”
used to help identify an organism based on it characteristics
at each step in a dichotomous key you have 2 choices

15. MODERN CLASSIFICATION
Today, taxonomists classify organisms in such a way as to indicate evolutionary relationships.
called
phylogenetic classification
Archaeopteryx – believed
to be the ancestor of birds

16. Modern Taxonomy IS NOT BASED ON HABITAT!!!! Today, taxonomists use…
comparative morphology
fossil evidence
embryological evidence
chromosomal evidence
biochemical similarities
physiological similarities
evolutionary relationships
to determine the classification of an organism

17. PHYLOGENY = THE EVOLUTIONARY HISTORY (relationships) OF A SPECIES
PHYLOGENETIC TREE = TREE OR DIAGRAM THAT REPRESENTS THE EVOLUTIONARY HISTORY OF A SPECIES

20. DERIVED CHARACTERS are used to help determine evolutionary relationships
Derived Character - a feature (trait) that apparently evolved only within a specific groups of organisms
examples….
jaws, lungs, claws, feathers, mammary glands,….

21. CLADOGRAM - diagram made by cladistic analysis that shows the evolutionary relationships of organisms
cladistic analysis help to determine evolutionary relationships (phylogeny) so that phylogenetic trees are more “accurate”

23. 2 Modern Systems of Classification
Today, we use the 6 kingdom system However, because of differences in cellular structure and molecular/chemical structure, scientists have added a larger/broader taxon – called a domain – this is known as the 3 domain system

24. 2 Modern Systems of Classification
3 domain system kingdom system
Domain archaea Kingdom archaebacteria
Domain bacteria Kingdom eubacteria
Domain eukarya Kingdom protista
Kingdom fungi
Kingdom plantae
Kingdom animalia

25. Differences among Kingdoms
Archaebacteria and Eubacteria: prokaryotic, unicellular
Protista: eukaryotic, unicellular and multicellular
Fungi: eukaryotic, cell wall of chitin, no chloroplasts, unicellular and multicellular, absorptive heterotrophs
Plantae: eukaryotic, cell wall of cellulose, chloroplasts, all multicellular, autotrophic
Animalia: eukaryotic, no cell wall, all multicellular, heterotrophic

26. BACTERIA are divided into 2 Kingdoms Archaebacteria and Eubacteria (previously classified together as kingdom Monera)

27. 3 shapes
spiral rod round

28. Bacteria…. Eubacteria and Archaebacteria
many are saprophytic (feed on dead organic matter)
many are parasitic (feed on living organic matter)
among the first forms of life
prokaryotic cells
unicellular
ONLY KINGDOMS lacking
an organized nucleus and
membrane-bound organelles
Nostoc (cyanobacterium)

30. Methods of energy acquisition (or modes of nutrition)
Some are capable of ….chemosynthesis
Some are capable of ….photosynthesis
Others are heterotrophic

31. Bacteria – Roles in the Environment
some cause disease – INCLUDING strep throat, tooth decay, gum disease, flesh eating strep bacteria and many more…
photosynthesis and oxygen production
cyanobacteria (“blue-green bacteria”) contributed to formation of atmospheric oxygen by photosynthesis
Cause spoilage of food
food source (used to flavor foods such as …Yogurt, vinegar, cheese, buttermilk, sour cream
Important in nutrient transfer
convert atmospheric (gaseous)N into forms useable by plants and animals
Lyme disease – carried by mammals and birds, transmitted by ticks to humans
Many heterotrophic bacteria also cause diseases such as strep throat, rheumatic fever, cholera, gonorrhea, syphilis, and toxic shock syndrome. Bacteria can cause disease by destroying cells, releasing toxins, contaminating food, or by the reaction of the body to the infecting bacteria. Bacterial infections can be controlled by vaccinations and antibiotic treatments. Antibiotics interfere with some aspect of the replication of bacteria, and are produced by microorganisms such as fungi, that compete with bacteria for resources. Penicillin, the first antibiotic discovered, inhibits the synthesis of new cell walls in certain types of bacteria. However, the overuse of antibiotics during the past fifty years has led to natural selection favoring antibiotic resistance. There are reportedly more than 50 strains of antibiotic resistant bacteria, necessitating the development of new antibiotics and the frequent change of antibiotics in treatment.

32. Bacteria – Roles in the Environment
decomposition
saprophytic (decompose dead tissue)
symbiotic (live within a host organism)
These decomposing bacteria are often used in sewage treatment plants
some oil deposits are attributed to cyanobacteria
There are also oil eating bacteria – used to clean up oil spills
Used in biotechnology applications- we can take human genes and insert them into bacteria – turning them into “factories” that then produce HUMAN INSULIN and HUMAN GROWTH HORMONE

33. Kingdom Archaebacteria (“old bacteria”)
cell wall does not contain peptidoglycan
have unusual lipids in cell membrane
oldest and most primitive organisms known
life’s extremists - occupy environments that “normal” organisms find too harsh

34. Archaebacteria….3 groups….
Methanogens - produce methane gas, found in soil, swamps, digestive tracts of animals
Extreme Halophiles – live in high salt environments, found in salt lakes, Dead Sea
Thermoacidophiles – live in hot, acidic environments, found in volcanic vents, hydrothermal vents

35. Kingdom Eubacteria (“true bacteria”)
cell wall contains peptidoglycan
includes most of the bacteria that affects our daily life including….
tetanus, strep throat, tooth decay,
E. coli, salmonella, botulism,
lyme disease, syphilis, and many more….

36. Kingdom Protista

37. Kingdom Protista
Method of energy acquisition - heterotrophic and autotrophic
Eukaryotic cells
Found in freshwater, saltwater, soil, also live in other organisms
because of great diversity, classification is difficult
Euglena, diatoms, paramecium

38. 3 groups of protista “animal-like” protists (called protozoans),
include paramecium, amoeba
“plant-like” protists (called algae)
includes euglena, diatoms, dinoflagellates
“fungus-like” protists
includes slime molds and water molds

39. PARAMECIUM
EUGLENA
AMOEBA

40. Protista – Roles in the Environment
photosynthesis and oxygen production
food source (algae)
animal feed, fertilizers
algae sheets used in some Japanese dishes
additive to puddings, ice cream, salad dressing, candy (carrageenan and alginate)
Some can cause disease
avian malaria, human malaria,
amoebic dysentery

41. Protista and Red Tides
Occurs when there is a population explosion of dinoflagellates
neurotoxin is released
shellfish eat dinoflagellates and concentrate toxin
humans can be killed by eating shellfish contaminated by toxin

42. Kingdom Fungi mushrooms, blights, rusts, molds, puffballs, morels, yeasts, truffles, toadstools, shelf fungi,….

43. Fungi Eukaryotic cells
made up of hyphae – threadlike filaments that make up the body of a fungus
mycelium= mass of hyphae
no roots, stems or leaves
no chlorophyll
Method of energy acquisition: saprophytic or parasitic
reproduce by spores
cell walls contain chitin
UNIQUE IN THAT THEY ARE absorptive heterotrophs
Both multicellular and unicellular species

44. Roles of Fungi in the Environment
Food Source
mushrooms, truffles, morels, cheeses, bread, beer and wine
Production of some Antibiotics
Some are parasites of crops and plants
cause loss of food plants, spoilage, infectious disease
Dutch Elm Disease
Chestnut Blight
Benefit Wildlife
food source, nest sites, hiding places and cover
Symbiosis - Mutualism
lichens (fungus + alga)
mycorrhizae (fungus and plant roots)

45. Kingdom Plantae

46. Plants eukaryotic, multicellular, photoautotrophs
cell wall with cellulose
2 major groups of plants
nonvascular
and
vascular
Fungi, lichens

47. Nonvascular Plants small – usually under 5” tall
NO VASCULAR TISSUES - lack conducting cells for water and food
likely were the earliest land plants
liverworts, hornworts and mosses
Fungi, lichens

48. Vascular Plants have specialized cells for transporting materials
Xylem (for transporting water and mineral nutrients)
Phloem (for transporting sugars from leaves to the rest of the plant)
pines, cacti, grasses, trees, flowers, …..

49. Roles of Plants in the Environment
food source
generate oxygen
provide habitat for humans and wildlife
American chestnut, late 1800s

50. invertebrates and vertebrates
Kingdom Animalia
multicellular
heterotrophic
Eukaryotic cells
no cell wall
2 main groups
invertebrates and vertebrates

51. Invertebrates (animals without a backbone)
sponges, jellyfish, corals, insects, worms, rotifers, comb jellies,…

52. Vertebrates animals with a backbone (of bone or cartilage)
5 groups of vertebrates - fish, amphibians, reptiles, birds, mammals

53. Roles of Animals in the Environment
food source
most serve as predators in some capacity – and limit populations of other organisms
scavengers
“shape” habitats for other wildlife

54. Viruses – not living
Do have genetic material and some other characteristics of cells but do not exhibit all the characteristics of life
However, biology usually involves a study of viruses because they infect cells

55. How are Viruses different from Bacteria?
Subcellular
Intracellular parasite
No nucleus
No organelles
have genetic material
Have a protein coat (capsid)
Bacteria
Prokaryotic cells
No nucleus
Have organelles
Have genetic material
Have a cell membrane and many have a cell wall

56. Viruses infect all groups of organisms – however, they are very specific
Plant viruses infect a specific plant or group of related plants
Human viruses only infect humans
Bacterial viruses infect bacteria

57. is a virus that infects a bacterium
BACTERIOPHAGE
is a virus that infects a bacterium

58. Other viral shapes…

59. Let’s Review This characteristic separates which kingdoms….
All members are heterotropic?
All members are autotrophic?
Contains both heterotrophic and autotrophic members?
All members prokaryotic?
All members eukaryotic?
Have chloroplasts?
Have a cell wall?
All members unicellular?
All members multicellular?
Contains both unicellular and multicellular members?
Autotrophic = Plantae
Heterotrophic = Fungi, Animalia
Heterotrophic and Autotrophic = Monera, Protista