Transcript classification - cloudfront.net

CLASSIFICATION
Finding Order
in Diversity
Organism
Number
Described
Estimated number to be
Discovered
Viruses
5,000
about 500,000
Bacteria
4,000
400,000-300 million
Fungi
70,000
1-1.5 million
Protozoans
40,000
100,000-200,000
Algae
40,000
200,000-10 million
Flowering plants
250,000
300,000-500,000
Roundworms
15,000
500,000-1 million
Mollusks
70,000
200,000
Crustaceans
40,000
150,000
Spiders and mites
75,000
750,000-10 million
Insects
950,000
8-100 million
Vertebrates
45,000
50,000
TAXONOMY
• The classifying of
organisms and the
assigning of a
universally
accepted name to
each.
WHY CLASSIFY?
1. To study the diversity of
life, biologists use a
classification system to
name organisms and group
them in a logical manner.
WHY CLASSIFY?
2. When taxonomists classify
organisms, they organize
them into groups based on
similarities.
WHY CLASSIFY?
3. Classification makes life
easier. What are some ways
we classify?
ASSIGNING
SCIENTIFIC NAMES
• Using common names can be
confusing because many
organisms may have several
different common names.
• The cougar is also known as
the mountain lion, puma or
catamount…thus the need
for a scientific name.
Felis concolor
• A Swedish botanist named
Carolus Linnaeus developed
Binomial Nomenclature, a
two-word naming
system for naming
all species on earth.
What do botanists
study?
ASSIGNING SCIENTIFIC
NAMES
• The first part of the
scientific name is the
genus. This word is
always written first and Homo sapien
the first letter is
capitalized. It appears
in italics or is underlined.
Ursus arctos
ASSIGNING SCIENTIFIC
NAMES
• The second part of the
scientific name is the
species name. This word
is always written second
and the first letter is Homo sapien
lower-case.
It appears in italics or is
underlined.
Ursus arctos
LINNAEUS’S SYSTEM OF
CLASSIFICATION
• Linnaeus’s hierarchical
system of classification
includes seven levels. They
are, from largest to smallest,
Kingdom, Phylum, Class,
Order, Family, Genus,
Species.
LINNAEUS’S SYSTEM OF
CLASSIFICATION
• The Kingdom is the largest and
most inclusive (includes) of the
taxonomic categories.
• Species is the smallest and
most specific of the taxonomic
categories. It includes one
LINNAEUS’S SYSTEM OF
CLASSIFICATION
• The more taxonomic
levels that two
organisms share, the
more closely related
they are considered to
be.
LINNAEUS’S SYSTEM OF
CLASSIFICATION
What do the scientific names of the
polar, grizzly and panda bears tell you
about their similarity to each other?
Ursus maritimus
Ursus arctos
Ailuropoda
melanoleuca
THINKING CRITICALLY
Organism
Cat
Wolf
Fly
Kingdom
Animalia
Animalia
Animalia
Phylum
Chordata
Chordata
Arthropoda
Class
Mammalia
Mammalia
Insecta
Order
Carnivora
Carnivora
Diptera
Family
Felidae
Canidae
Muscidae
Genus
Felis
Canis
Musca
F. domesticus
C. lupus
M. domestica
Species
THINKING CRITICALLY
1. What type of animal is
Musca domestica?
Animal; insect
2. From the table, which
2 animals are most
Cat and Wolf
closely related?
3. At what classification
level does the
Family Level
evolutionary
relationship between
cats and wolves diverge
(become different)?
Human classification:
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Primates
Family
Hominidae
Genus
Homo
species
sapiens
EVOLUTIONARY
CLASSIFICATION
• Organisms aren’t just grouped
based on similarities. These
evolutionary relationships or lines
of descent are also used in
classification.
• Phylogeny: The study of
evolutionary relationships among
organisms.
What determines evolutionary
relationship?
• Anatomy and physiology
– Common structures imply a common ancestor.
• Breeding and behavior patterns
• Geographic distribution
• DNA and biochemistry
DNA comparisons between these plants show almost
no difference.
EVOLUTIONARY
CLASSIFICATION
A
B
C
D
E
F
Clade or
lineage
Speciation: formation of two
new species from one
T
I
M
E
CLADOGRAM
Hagfish
Fish
Lizard
Frog
Mouse
Pigeon
Chimp
Feathers
Fur &
Mammary
Glands
Lungs
Jaws
Claws
or Nails
VENN DIAGRAMS
• Venn Diagrams can be used to make
models of hierarchical classification
schemes. A Venn diagram is shown
below:
A.
B.
C.
D.
A.
B.
C.
D.
• Four groups are represented by circular regions
• Each region represents different taxonomic
levels.
• Regions that overlap, share common members.
• Regions that do not overlap do not have common
members.
A.
B.
C.
D.
Matching:
Mammals C
Animals with backbones B
Insects D
All animals A
Dichotomous key:
• A key that is used to identify different
organisms based on physical
characteristics.
• It is made up of sets of two statements
that deal with a single characteristic of
an organism, such as leaf shape
(toothed or smooth edge) or hair (has
hair or doesn’t have hair)
So how are all living things put
into these different groups?
• All living things are classified based on
several features:
–
–
–
–
–
Cell type
Number of cells
Cell structures
Mode of nutrition
Motility
Remember the 2 Cell Types?
• Prokaryotic
– Small, simple cells without
membrane-bound
organelles; i.e. bacteria
• Eukaryotic
– Large, complex cells
containing many specialized
organelles, nucleus; i.e.
plants, animals, protists &
fungi
Domains
• Largest , most inclusive group
– Bacteria: Prokaryotic cells
• 1 kingdom: Eubacteria
– Archaea: Prokaryotic cells
• 1 kingdom: Archaebacteria
– Eukarya: Eukaryotic cells
• 4 kingdoms: Protista, Fungi, Plantae, Animalia
Kingdom Eubacteria
• Unicellular
• Very strong cell
walls
(peptidoglycan)
• Autotrophic or
heterotrophic
• diverse habitat
• Some motile, other
non-motile
• Ex: streptococcus,
Escherichia coli
Kingdom Archaebacteria
• Most live in extreme
environments
– Most do not use oxygen to
respire (anaerobic).
– Ancestor to eukaryotes
• Unicellular
• Cell walls lack peptidoglycan
• Can be heterotrophic or
autotrophic
• Some motile, others nonmotile
• Examples: Halophiles,
methanogens.
Kingdom Protista
• Most are unicellular, few are
multicellular
– lacks complex organ systems
• lives in moist environments
• diverse metabolism/motility
– Animal-Like
– Plant-Like (cellulose,
chloroplasts)
– Fungus-Like
• Ex: paramecia, euglena,
algae, slime molds
Kingdom Fungi
• Saprobes: decomposes
matter by absorbing
materials
• Multicellular
(mushrooms) or
unicellular (yeast)
• Cell walls (chitin)
• Non-motile
Kingdom Plantae
• Multicellular
• Autotrophic:
Photosynthetic
– Cells contain
chloroplasts
• Immobile
• Cell walls
(cellulose)
• Ex: grass, rose,
moss
Kingdom Animalia
•
•
•
•
•
•
Multicellular
Mobile (at one point during their lifetime)
Lack cell walls
Diverse habitats
Heterotrophic
Ex: insects, worms,
squirrels, birds
Nutritional types
Auto(photo)
Hetero(absorb) Hetero(ingest)
Fungi
(Seaweeds)
Protista
Eu
Pro
Bacteria
Animalia
Multi
Uni