Download Classification of Living Things

Classification Systems
Shape Activity
• First, Cut out the Shapes
• Arrange shapes into groups
–You must have at least 4 groups
• Give each group a name
• Give each shape within the group a
name
–Glue the groups on to the paper in
their own section
• Wait for discussion
Why Classify?
• Name organisms
• Group them in a logical manner
Taxonomy
• The science of classifying organisms and
assigning each one a universally accepted
name
– Scientific Naming
– Binomial Nomenclature
• Name consists of the Genus and species
• Why a Scientific Name….
Common Name
Different Animal
•
American Opossum
Australian Possum
Same Animal
different common name
• Depending on the region
• called striped mullet, black mullet, flathead
grey mullet
Scientific Name (Binomial Nomenclature)
Example: Red Maple (this is the common name)
• Acer rubrum (italicized or underlined)
– Acer, is the genus (the latin word for maple)
– rubrum is the species (rubrum is the latin
word for red)
Why is it important to
have a scientific name
and not just a common
name?
Biological Classification
• Linnaeus developed this system and
placed living things into levels of
classification.
– Based his system on specific traits
– Includes more groups than older systems
• Each level is called a taxon (taxa)
Linnaeus’ Classification
System
•
•
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•
•
•
•
Kingdom
Phylum
Class
Order
Family
Genus
Species
Use a mnemonic to help you
• King Phillip Came Over For Good Soup
Kingdom
• The largest group
• Contains several phyla
Example: Kingdom Animalia
consumers, multicellular,eukaryotes
(a) A sea star
Phylum
• Includes several classes
• Includes a large number of different
organisms.
• The organisms share some important
basic characteristics
• Example: Phylum Chordata
• Includes mammals, birds, fishes,
amphibians and reptiles
What do these animals have in common?
Class
• A group of closely related orders
Example: Mammalia (covered with fur, warmblooded, nurse their young)
Order
• Several families of similar organisms
– Example: Carnivora, includes cats, dogs, ,
etc.
– Carnivores are meat-eaters
Family
• Larger than a genus
– Contains several related genera
– Example: Lions, tigers, cheetahs (all catlike
animals belong in the family Felidae)
Genus
• Species that share common
characteristics
– Example: Felis (contains the common house
cat as well as the cougar and puma. (Small
cats.)
– Have similar teeth, feet, and claws
Species
• Population of organisms that share similar
characteristics and that can breed with
one another and produce fertile offspring
– Example: catus (a tame cat)
Kingdom
• When first introduced all phyla belonged to
either the Kingdom Animalia or Plantae
• The scientific view of life was not as
complex in Linnaeus’s time
Early Classification
• Traits used to separate Animals from
Plants
– Animals were mobile, used food for energy
– Plants were green and photosynthetic
• Two Kingdoms were not enough
to logically include all organisms
The Six-Kingdom System
• Animalia
• Plantae
• Fungi
– Yeast, mushrooms and molds
• Protista
– Many microorganisms
• Bacteria
• Archae
The Three-Domain System
• The Domain is larger than a Kingdom
• Scientists have used molecular analyses
to group organisms into domains
– Note: This was not part of Linnaeus’ System
• The Three Domains:
• Bacteria
• Archaea
• Eukarya
– Eukaryota
Domain - Bacteria
Kingdom Bacteria
( common bacteria)
• Characteristics
– Prokaryote (no nucleus)
– Composition of cell wall different from archaebacteria
– Unicellular
– Autotroph, heterotroph or chemotrophic (energy from
chemicals)
• HONORS
• Contain peptidoglycan in cell wall
• Peptidoglycan is a sugar polymer. These bacteria are less complex
and easier to treat.
•
Escherichia coli
Streptococcus
Domain Archaea
Kingdom Archaea
( Archa – means “initial”, also known as extreme bacteria)
• Characteristics
– Prokaryote
– More complex cell wall composition
– Unicellular
– Autotroph, heterotroph or chemotrophic (energy from
chemicals)
Halophile’s (salt loving bacteria) in the Sierra Navada
(aerial view)
•
Halophile bacteria in Lake Natron, Tanzania
Thermophiles – heat
loving. Live near
volcanoes. Mt.St
Helens
• Methanogens – live with no oxygen –
• make methane gas (natural gas or swamp gas)
Domain Eukarya
Kingdom Protista
• Characteristics
– Eukaryote (contain a nucleus)
– Most unicellular (some multicellular)
– Autotroph or heterotroph
https://www.youtube.com/watch?v=-zsdYOgTbOk
Examples of Protists
•
Amoeba
euglena
Paramecium
Giant Kelp and
sea weeds
Sporozoites –
parasite causes
malaria
Slime mold
Domain Eukarya
Kingdom Fungi
• Characteristics
– Eukaryote
– Cell walls made of chitin
• Material that makes up exoskeleton of insects and
arthropods.
– Most multicellular (some unicellular)
Heterotroph
https://www.youtube.com/watch?v=YyUWa84bGgA
Examples of Fungi
Mushrooms, puffballs,
shelf fungi
Athlete’s foot
and ringworm
Yeast – Only unicellular
fungi
Domain Eukarya
Kingdom Plantae
• Characteristics
– Eukaryote
– Have Cell walls made of cellulose
– Contain chloroplasts
– Multicellular
– autotroph
•
•
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Bryophytes – Nonvascular plants
https://safeshare.tv/x/ss5887b6fe44aea
Ferns – vascular seedless
https://www.youtube.com/watch?v=c4YtOT
0Z6Ek
• Seed plants - Gymnosperms
• https://www.youtube.com/watch?v=zKnrlUI8
5ys
• Seed plants – flowering plants angiosperms
https://www.youtube.com/watch?v=ph7Ex8rQ
Examples of Plants
Mosses, and ferns the
seedless plants
Flowering seed
plants
Seed plants/nonflowering - conifers
Domain Eukarya
Kingdom Animalia
• Characteristics
– Eukaryote
– No cell walls or chloroplasts
– Multicellular
– heterotroph
• Examples of Animals
Problems with Classification
• Which characteristics are more important?
– Those we can see….
– Or those we can’t
Classifying only observable traits can pose
problems
Think about it.
• Linnaeus tried to group organisms
according to biologically important
characteristics
• This was more than a century before
Darwin’s ideas about evolution.
– And how organisms are related
What is the problem with classifying based on
body structure comparisons?
•
Barnacles and limpets would
be grouped together
The problem is…which
similarities and differences
are most important?
Grouping based on the lines of evolutionary
descent
Darwin’s theory of evolution changed the way biologists
thought about classification
Crabs and
barnacles are more
closely related and
are grouped
together.
Organisms are grouped into
categories that represent
lines of evolutionary descent,
not just physical similarities
Evolutionary Classification
• Phylogeny-the study of how living and
extinct organisms are related to one
another.
• The strategy is to group organisms
together based on their evolutionary
history (evolutionary classification)
– Look at their evolutionary descent rather than
similarities and differences
Bozeman Science Phylogenies
https://www.youtube.com/watch?v=fQwI90bkJl4
Evolutionary Classification
• Common Ancestors
– Phylogenetic systematics places organisms into
higher taxa
– The larger a taxon is, the farther back in time its
members shared a common ancestor.
Phylogeny Example
Cladogram
• Classifying organisms according to these rules places them into
groups called clades
• Clade – is a group of species that includes a single common ancestor
and all descendants of that ancestor – living and extinct.
At each juncture
is a new
evolutionary trait
Cladogram example of barnacles and limpets
•
Similarities in DNA and RNA
• Similarities in DNA can be used to help
determine classification and evolutionary
relationships
• DNA of different organisms can be “read” and
compared to trace the history of genes.
• They are useful because all organisms have
either DNA or RNA
Comparing DNA of different species. The more similarities
in the DNA sequence, the more closely related the species.