Download Classification ppt - Madison County Schools

Today you need:
Classification notes from orange
bin.
Writing utensil
If you were not here yesterday: the
biological classification packet in
yellow bin.
If you have not taken your exam,
you need to do so during SSR
today.
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Classification
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 Biodiversity – the variety of organisms in an
ecosystem.
 10 million species known to exist today.
 Possibly 30 million+ undiscovered species of
insects alone.
 Relationship between organisms determined by:
 Evolutionary relationship
 Biochemistry
 Behavior
 Developmental stages
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Classification
 8 Levels of classification in modern system.
 There used to be 5 levels in the original Linnaeus system
 Each level is called a taxon and can change as more
information becomes available. Add ex. phylogenetics
 Can be used to classify all BUT asexually reproducing
species
1. Domain (largest category, organisms are least similar)
2. Kingdom
3. Phylum
4. Class
5. Order
6. Family
7. Genus (smallest category, organisms most similar)
8. Species (down to a single organism!)
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Acronym for remembering this is?
Write one of these down.
Do Kangaroos Prefer Cake Or
Frosting, Generally Speaking?
Didn’t Know Popeye’s Chicken
Offered Free Gizzard Strips.
Or make your own.
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Which is more closely related to the …
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Domain – broadest level, includes 3 lineages:
1. Archaea: similar to Bacteria, but inhabit extreme, hostile
environments (hot springs, deep-sea thermal vents, salty lake,
no O2). “Ancient”
2. Bacteria: unicellular prokaryotic organisms. Lack
membrane-bound organelles and nucleus. Has a cell wall.
3. Eukarya: multicellular eukaryotic organisms. Has
organelles and a nucleus.
Add “True nucleus”.
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Kingdoms
 6 different kingdoms in modern system
 Used to be 5 because …
 Archaebacteria & Eubacteria used to be 1 kingdom
known as Monera.
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Kingdom Archaea (Domain Archaea)
•Prokaryotic – no nucleus or membrane bound organelles
•Used to be in Kingdom Monera with bacteria
•Unicellular and microscopic
•Live in extreme environments (Salty lakes and boiling hot
springs)
•***Not on handout – All prokaryotes do have the following:
DNA, Ribosomes, Proteins, Cell Membrane – why?
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Kingdom Bacteria (Domain Bacteria)
•Prokaryotic – no nucleus or membrane bound
organelles
•Used to be in Kingdom Monera with archaea
•Unicellular and microscopic
•Can be a PRODUCER
•Normal bacteria
•GRAM STAIN
Used to differentiate between
different types of bacteria
(Gram + or Gram -)
•FACT
Penicillin stops kills bacteria by stopping
their production of cell walls 12
ENDOSYMBIOSIS -symbiosis in which one of the
symbiotic organisms lives inside the other.
Ex. Mitochondria in a eukaryotic cell.
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Kingdom Protista (Domain Eukarya)
•Eukaryotic – nucleus and membrane bound organelles
•Diverse collection of mostly single celled organisms
•Can be “animal like” or “plant like”
•Algae is an example of plant like (is autotrophic –
photosynthesis) – these are PRODUCERS
•Animal like protists are called protozoans
•Recent evidence suggests this kingdom should be split
into multiple kingdoms
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Kingdom Fungi (Domain Eukarya)
•Eukaryotic - nucleus and membrane bound organelles
•Multicellular
•Includes mushrooms, molds, yeasts
Mode of nutrition
Heterotrophic - Mostly decomposers (break down remains of
dead organism and organic wastes, such as leaf litter and animal
feces, and absorb the nutrients into their cells)
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**Additional Info about the
Kingdom Fungi not on note
handout
• Produce spores that can survive for very long
periods of time in unfavorable conditions and will
wait to sprout until conditions are favorable for
the adult fungi to survive
• Have a branching network called hyphae that work
with their roots to digest the surface they are
growing off of
• Have a cell wall NOT composed of cellulose
• Some of them can produce toxic chemicals
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Kindgom Plantae (Domain Eukarya)
•Eukaryotic - nucleus and membrane bound organelles
•Multicellular
•Plants
•Nonmotile
•Special Organelles (that animals don’t have) – 1) Cell walls made of
cellulose, 2)Chloroplast, 3)Central vacuoles
Mode of Nutrition
Autotrophic - Produce own food through photosynthesis
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Kingdom Animalia (Domain Eukarya)
•Eukaryotic - nucleus and membrane bound organelles
animals
•Multicellular
•Motile
•Lack rigid cell walls, chloroplasts, and central vacuoles
Mode of nutrition
Heterotrophic – eat different organisms for food
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VIRUSES
•Viruses are considered NON-LIVING because
they are not made of cells.
•So, what kingdom would they be classified in?
More facts about viruses:
•Require a host to reproduce
•Made only of protein and DNA
•No known cures for human viruses. If you get one,
you will have it for life.
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Taxonomy – science of classifying organisms.
(Phylogenetics is classifying organisms based off of their
evolutionary history)
Aristotle (about 2,400 years ago)
 1st scientist to classify organisms
 Only two groups (plant & animal) based on habitat and stem
structure.
 Common names & long descriptions
Carolus Linnaeus (year 1735)




“father of modern taxonomy”
Based on structural similarities.
Originally has 5 levels of classification.
Used 2 name, naming system (binomial nomenclature)
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Binomial nomenclature – 2 name naming system.
“Genus & species”
First word capitalized, second word not.
Always italicized or underlined.
Always in Latin because…
 Dead language (not subject to change in meaning “slang”)
 It is universal
Example: Homo sapien or Homo sapien
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Dichotomous key
 "divided into two choices“
 looks at the similarities and
differences
 leads the user to the organism’s name
MONEY TAXONOMIC KEY
1 A. Metal....................................................go to 2
1 B. Paper....................................................go to 5
2 A. Brown (copper)........................................penny
2 B. Silver....................................................go to 3
3 A. Smooth edge...........................................nickel.
3 B. Ridges around the edge...............................go to 4
4 A. Torch on back..........................................dime
4 B. Eagle on back...........................................quarter
5 A. Number 1 in the corners...............................$1 bill
5 B. Number 2 in the corners...............................$2
bill
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Problems with Taxonomy
 Classifying species into higher taxa is useful, but
ultimately arbitrary
 Higher classification levels are defined by various
morphological characteristics instead of measurable
differences that could be used to apply to an entire
taxon level
 Therefore, many biologists now propose that
classification be based solely off the evolutionary history
of an organism (Phylogenetics)
 Add this: Phylogenetics: organisms related
based on their DNA sequences.
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Classifying organisms based on
Evolution
 Phylogeny – the evolutionary relationship between
organisms. (genetics)
 Cladogram / Phylogenetic Tree- looks like family tree,
used to show evolutionary history of organisms
 Evidence of shared ancestry:




Fossil records
Homologous features
Embryological evidence
Add: genetics
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 Analogous structures - traits that have similar use, but different
structure. Due to structure being used in similar way
 Homologous structures – traits that have similar structure, but
have different uses. Due to common ancestry.
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Cladistics (Cladograms)
 Organisms are grouped into clades
 A clade is a group of species that includes an ancestral
species and all of its descendants
 Based on a new trait developing and being passed
down to descendants
 Groups of organisms that share these new traits are
more closely related to each other than to groups who
only have ancestral traits
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Making Cladograms / Phylogenetic
Trees
 Shared derived characters – new traits that are
shared by a group
 These shared derived characteristics distinguish
between clades and are “branches” in the tree of life
(and branches in cladograms)
 Shared ancestral characters – original traits present
in ancestral groups
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Making Cladograms /
Phylogenetic Trees – Character
Tables
 Character Table - Table used to generate phylogenetic
trees by comparing characteristics of species.
 Each new character represents the divergence of two
groups from a common ancestor (one without the
new characteristic and one with it) and thus shows
the order in which new traits evolved.
 Ingroup – group of taxa that is actually being analyzed
 Outgroup – species or group of species that is known to have
diverged before the lineage that contains the groups we are
studying
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Rules for making character table
 Organisms go on top of chart
 List organisms from oldest to youngest going from left to right
 Organisms that have the MOST TRAITS of those being studied will be the
YOUNGEST. This is because they evolved most recently and thus would
had diverged from an ancestor that had already acquired these traits;
therefore, when they diverged they too would have these traits plus
some additional ones.
 In the same sense, the organisms that have the LEAST TRAITS of those
being studied will be the OLDEST because they diverged from an
ancestor before these traits appeared
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Rules for making a character table
continued
 Traits go on the left side
 List traits from newest to oldest going from top to
bottom
 The traits that are shown by the LEAST organisms will be
the YOUNGEST because they appeared more recently;
therefore, there would not have been as much time for
speciation to occur creating multiple species with the trait.
 The traits that are shown by the MOST organisms will be
the OLDEST because they appeared early in the
evolutionary lineage; therefore, all organisms that diverged
after that trait appeared would acquire that trait from their
ancestor.
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hagfish
perch
salamander
lizard
pigeon
mouse
chimp
Fur;
mammary
glands
0
0
0
0
0
1
1
Feathers
0
0
0
0
1
0
0
Claws or
nails
0
0
0
1
1
1
1
Lungs
0
0
1
1
1
1
1
Jaws
0
1
1
1
1
1
1
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hagfish
perch
salamander
lizard
pigeon
mouse
chimp
Fur; mammary
glands
0
0
0
0
0
1
1
Feathers
0
0
0
0
1
0
0
Claws or nails
0
0
0
1
1
1
1
Lungs
0
0
1
1
1
1
1
Jaws
0
1
1
1
1
1
1
Tips for reading a cladogram
1.Extant (living species) will be up top
2.Extinct species will be on bottom
3.They can be turned either way and be read the same.
4.The youngest species will be the one with the shortest divergence line (and the oldest will
be the one with the longest)
5.Each node represents divergent evolution. Typically, cladograms are based off of the
emergence of a new morphological trait that all species from that point forward will show
(because they come from this ancestor that had the trait) but none of the organisms before
will (because they evolved before the trait appeared)
6.A species will be most related to (because they share the most recent common ancestor
with) the species that evolves after them.
7.The most recent common ancestor of 2 extant species can be found by tracing the line
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back to where they diverged.