Transcript Classification

Classification
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Section:
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The Challenge
• Biologists have identified and
named approximately 1.5 million
species so far.
• They estimate that between 2 and
100 million species have yet to be
identified.
Finding Order in Diversity
•
1. Why Classify?
– To study the diversity of life
– To organize and name organisms
2. Why give scientific names?
– Common names are misleading
•
jellyfish
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silverfish
None of these animals are fish!
star fish
Why Scientists Assign Scientific Names to Organisms
Some organisms have several common names
This cat is commonly
known as:
•Florida panther
•Mountain lion
•Puma
•Cougar
Scientific name: Felis concolor
Scientific name means “coat of one color”
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Section:
Origin of Scientific Names
• By the 18th century, scientists realized that
naming organisms with common names was
confusing.
• Scientists during this time agreed to use a
single name for each species.
• They used Latin and Greek languages for
scientific names.
Slide # 6
Linnaeus: The Father of Modern Taxonomy
1732: Carolus Linnaeus developed
system of classification – binomial
nomenclature
a. Two name naming system
b. Gave organisms 2 names
Genus (noun) and species (adjective)
Rules for naming organisms
1. Written is Latin (unchanging)
2. Genus capitalized, species lowercase
3. Both names are italicized or underlined
EX: Homo sapiens: wise / thinking man
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Section:
Carolus
Linnaeus
Linnaeus’s System of Hierarchy
Least
specific
Kingdom
1.
Phylum
Class
2.
a.
Family
c.
Class
b.
Species
d.
Order
Order
Based on their names, you know that
the baboons Papio annubis and Papio
cynocephalus do not belong to the
same:
Family
a.
Family
c. Order
b.
Genus
d. Species
Genus
Most
specific
Species
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Section:
Which of the following contains all of the
others?
SPECIES
Binomial Nomenclature Example
• For example, the polar bear is named
Ursus maritimus.
• The genus, Ursus, describes a group of
closely related bear species.
• In this example, the species, maritimus,
describes where the polar bear lives—on
pack ice floating on the sea.
Modern Classification
• Linnaeus grouped species into
larger taxa, such as genus and
family, based on visible
similarities.
• Darwin’s ideas about descent
with modification evolved into
the study of phylogeny, or
evolutionary relationships
among organisms.
Modern Classification
• Modern biologists group organisms into categories
representing lines of evolutionary descent.
• Species within a genus are more closely related to
each other than to species in another genus.
Genus: Felis
Genus: Canis
Similarities in DNA and RNA
• Scientists use similarities and differences in
DNA to determine classification and
evolutionary relationships.
• They can sequence or “read” the
information coded in DNA to compare
organisms.
Kingdoms and Domains
• In the 18th century, Linnaeus originally
proposed two kingdoms: Animalia and
Plantae.
• By the 1950s, scientists expanded the
kingdom system to include five
kingdoms.
The Five Kingdom System
Monera
bacteria
Protista
Amoeba, slime mold
Fungi
Plantae
Animalia
mushrooms, yeasts, molds
flowering plants, mosses, ferns,
cone-bearing plants
mammals, birds, insects, fishes,
worms, sponges
The Six Kingdom System
• In recent years, biologists have
recognized that the Monera are
composed of two distinct groups.
• As a result, the kingdom Monera has
now been separated into two
kingdoms: Eubacteria and
Archaebacteria, resulting in a sixkingdom system of classification.
The Three-Domain System
• Scientists can group modern organisms
by comparing ribosomal RNA to
determine how long they have been
evolving independently.
• This type of molecular analysis has
resulted in a new taxonomic
category—the domain.
The Three Domains
• The three domains, which are larger than
the kingdoms, are the following:
• Eukarya – protists, fungi, plants and
animals
• Bacteria – which corresponds to the
kingdom Eubacteria.
• Archaea – which corresponds to the
kingdom Archaebacteria.
Classification of Living Things
The three-domain system
Bacteria
Archaea
Eukarya
The six-kingdom system
Eubacteria
ArchaeProtista Plantae Fungi
bacteria
Animalia
Hierarchical Ordering of Classification
As we move from
the kingdom level
to the species level,
more and more
members are
removed.
Each level is more
specific.
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Section:
ARCHAE
BACTERI
A
EUBACTE
RIA
PROTIST
FUNGUS
PLANT
ANIMAL
Number of Cells
(single/multi)
Single
Single
Single
(except
algae)
Multi
(except
yeast)
Multi
Multi
Prokaryotic/
Eukaryotic
Prokaryotic
Prokaryotic
Eukaryotic
Eukaryotic
Eukaryotic
Eukaryotic
Producer/
Consumer
Both
Both
Both
Consumer
(decompos
er)
Producer
Consumer
Mobile/Non-mobile
Both
Both
Both
Nonmobile
Nonmobile
Mobile
Cell Wall
(yes/no)
Sometimes
Sometimes
No
Yes
(Chitin)
Yes
(Cellulose)
No
Answer the questions using this chart:
A
B
C
D
E
KINGD
OM
Animailia
Animalia
Animailia
Animalia
Animailia
PHYLU
M
Chordata
Chordata
Chordata
Chordata
Chordata
CLASS
Mammalia
Mammailia Mammalia
Mammailia
Reptilia
ORDER
Carnivora
Cetacea
Cetacea
Eusuchia
Carnivora
FAMILY Canidae
Dolphinida Hyaenidae
e
Dolphinidae Cercapithecida
e
GENUS
Tursiops
Hyaena
Orcinus
Crocodylus
aduncus
brunnea
orca
acutus
Lycaun
SPECIES pictus
Kingdom Archaebacteria
Cell Type
Prokaryote
Number of
Cells
Nutrition
Unicellular
Location
Extreme Environments Volcanoes,
Deep Sea Vents, Yellowstone Hot
Springs
Sometimes
Cell Wall
Examples
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Section:
Autotroph or Heterotroph
Methanogens
Thermophiles
Kingdom Archaebacteria
• Archaebacteria:
– Some scientists believe that archaebacteria are
the oldest living organisms.
– They live in extreme environments such as
sulphur springs, deep-sea volcanic vents, the
great salt lake, intestines of mammals, and the
reactors in nuclear power plants.
– Can be autotrophs (live near cracks in the ocean
floor)
Kingdom Eubacteria
Cell Type
Number of Cells
Nutrition
Prokaryote
Unicellular
Autotroph or
Heterotroph
Location
Everywhere!
Cell Wall
Sometimes
Examples
Streptococcus,
Escherichia coli
(E. coli)
Go to
Section:
E. coli
Streptococcus
Kingdom Eubacteria
• Eubacteria:
– These are the bacteria that we are more familiar
with.
– They are classified according to their shape and
their reaction to Gram staining.
Kingdom Eubacteria
• Some bacteria are heterotrophs.
– They must rely on other organisms as a food
source.
– Parasitic- get the nutrients they need by feeding
on living organisms.
– Saprotrophs- feed on dead organisms and
organic wastes.
Kingdom Eubacteria
• Some bacteria are autotrophs.
– Photosynthetic autotrophs- contain chlorophyll
and live in habitats where they get enough light
to go through photosynthesis.
– Chemosynthetic autotrophs- can also make
organic molecules for food, but they do so by
breaking down inorganic compounds that
contain nitrogen and sulfur.
Kingdom Protista
Cell Type
Eukaryote
Number of Cells
Most Unicellular,
some multicellular
Nutrition
Autotroph or
Heterotroph
Sometimes
Cell Wall
Examples
Amoeba,
Paramecium,
Euglena,
The “Junk-Drawer”
Kingdom
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Paramecium
Green algae
Amoeba
Kingdom Protista
• Kingdom Protista is called the catch all
kingdom because it contains so many
organisms that don’t fit into other
kingdoms.
• They can be unicellular or multicellular;
microscopic or large; autotrophs or
heterotrophs.
• All protists are eukaryotes.
Kingdom Protista
• Pseudopods- used by
some protists for
movement
Kingdom Protista
• Contractile vacuolewhen water enters the
protist, the contractile
vacuole contracts and
pushes the water back
out.
– Used by protists that
live in hypotonic
environments to keep
them from swelling
and bursting.
Kingdom Protista
• Animal-like protists:
– Called protozoans
– Single celled
– Ex.- amoeba, which moves by using
pseudopods and doesn’t have a cell wall
– Other protozoans move by cilia or flagella
– Can cause diseases such as malaria
Kindom Protista
• Plant-like protists:
– Algae- carry out photosynthesis, but do not
have roots, stems, leaves, or flowers like plants.
• Some algae contain other color pigments and appear
red, brown, or golden.
• Can be unicellular or multicellular and meters long
– Diatoms- unicellular protists that have a
glasslike outer shell.
Kingdom Protista
• Fungus-like protists:
– Decompose dead organisms
– Able to move from place to place for part of
their life cycle (true fungi cannot)
– Include slime-molds, downy mildews, and
water molds.
– Very colorful
Kingdom Fungi
Cell Type
Eukaryote
Number of Cells
Most multicelluar,
some unicelluar
Nutrition
Heterotroph
Cell Wall
Made of Chitin
Example
Mushroom, yeast,
mildew, mold
Most Fungi are
DECOMPOSERS
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Section:
Mushroom
Kingdom Fungi
• Can grow anywhere there is moisture
• Do not contain chlorophyll (this is why they
are not considered plants!)
• Are heterotrophs
• Fungus get their food by extracellular
digestion
– They send out hyphae into their food source.
These hyphae release enzymes that break down the
food into molecules that can be absorbed directly
by the hyphae.
Kingdom Fungi
• Have cell walls made of chitin
• Some are saprophytes
– Mushrooms
– Feed on dead organic matter
• Lichens- a mutualistic relationship between a
fungus and a green alga living close together.
– Lichens help break down rocks into soil so that
plants can grow.
Kindom Fungi
• Fungi can reproduce sexually, asexually, or
both.
– Yeasts reproduce asexually by budding or by
fission.
– Mushrooms reproduce sexually by forming
spores (haploid) that must germinate and fuse
to produce a new mushroom.
– Bread molds and other fungi can reproduce
sexually when conditions are right, or by
asexual spores.
Kingdom Plantae
Cell Type
Eukaryote
Number of Cells Multicellular
Nutrition
Autotroph
Cell Wall
Made of
cellulose
Mosses, ferns,
conifers,
flowering plants
Examples
Mosses growing
on trees
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Section:
Ferns :
seedless
vascular
Douglas fir:
seeds in cones
Sunflowers:
seeds in
flowers
Kingdom Animalia
Cell Type
Eukaryote
Number of Cells Multicellular
Nutrition
Heterotroph
Cell Wall
Examples
None
Sponges,
worms, insects,
fish, mammals
Bumble bee
Sage grouse
Jellyfish
Hydra
Poison dart frog
Sponge
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Section:
Cladogram
• An evolutionary tree that suggests how species may be
related
• Over evolutionary time, certain traits in a group of species,
or clade, stay the same. Other traits change.
Derived Characters
• Derived characters are traits that are shared by
some species but not by others
• The more closely related species are, the more
derived characters they will share
• Derived characters
are shown as
hash marks
Nodes
• Each place where a branch splits is called a
node.
• Nodes represent the most recent common
ancestor shared by a clade.
What do the house cat and the turtle have in common?
What does the leopard have in common with the wolf?
What organisms are most closely related?