Taxonomy
• Taxonomy- the science
of classifying
organisms into groups
• Think of the
classifications as a
hypothesis. As new
discoveries are made
and new technologies
are developed,
sometimes the
classifications change
Carolus Linnaeus
• Swedish naturalist who laid the foundation for our
modern classification system in the mid-1700s
including the use of binomial nomenclature
Linnaeus developed the scientific naming
system still used today.
• Taxonomy is the science of naming and classifying organisms.
• A taxon is a group of organisms in a classification system.
White oak: Quercus
alba
Binomial nomenclature is a two-part scientific naming system.
– uses Latin words
– scientific names always written in italics
– two parts are the genus name and species descriptor
Why Latin?
• Latin is a dead language (it isn’t spoken
natively anymore), so it isn’t changing
• Most scholars at the time new Latin
• Latin is a very descriptive language
• A genus includes one
or more physically
similar species
– Species in the
same genus are
thought to be
closely related.
– Genus name is
always capitalized.
• A species descriptor is
the second part of a
scientific name.
– always lowercase
– always follows
genus name; never
written alone
Scientific names help scientists to communicate
– Some species have very similar common names.
– Some species have many common names.
Linnaeus’ classification system has seven
levels.
• Each level is
included in the
level above it.
• Levels get
increasingly
specific from
kingdom to
species.
The Linnaean classification system has
limitations.
• Linnaeus taxonomy doesn’t account for molecular
evidence.
– The technology didn’t exist during Linneaus’ time.
– Linnaean system based only on physical similarities.
Vocabulary
Which term means one-celled? Many-celled?
• multicellular
• unicellular
Which term means that the organism produces
its own food? Consumes food?
• autotroph
• heterotroph
Vocabulary
• Prokaryotic – describes an organism with cells
that have a cell membrane but do NOT have a
nuclear membrane
• Eukaryotic – describes an organism with cells
that have a cell membrane and a nuclear
membrane
Vocabulary
• Autotrophic – makes its
own food
• Heterotrophic – gets
nutrients from the food
it consumes
List of the Three Domains and
the Six Kingdoms
1. Domain Bacteria
•
Kingdom Eubacteria
2. Domain Archaea
•
Kingdom Archaebacteria
3. Domain Eukarya
•
•
•
•
Kingdom Protista
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
http://www.tellapallet.com/tre
e_of_life.htm
Overview of the
Three Domains
and
Six Kingdoms
Kingdom Eubacteria
• Most abundant organisms on the Earth
• Bacteria can live in many places on earth,
inhabiting a wide variety of habitats, including
other organisms
• Unicellular
• Prokaryotic
• Autotrophic or heterotrophic
• Thick cells walls with peptidoglycan
Kingdom Eubacteria
• Bacteria come in
different shapes, such
as round, spiral and
rod-shaped.
Kingdom Eubacteria
• Bacteria can cause a wide variety of diseases, such as
strep throat, food poisoning and the Black Death
(bubonic plague of the Middle Ages)
Kingdom Eubacteria
• Bacteria also play an
important role in
decomposition,
nitrogen fixation and
human digestion (E.
coli)
Soybean root containing
billions of bacteria
Kingdom Eubacteria
• Procholorococcus – an
autotrophic bacterium –
What does that mean
about how it gets its
nutrients?
Kingdom Eubacteria
• Bacteria from a
Nitrifying Trickle Filter
(NTF) stained with
acridene orange. The
stain makes
DNA appear yellow and
RNA appear orange.
Kingdom Archaebacteria
• Bacteria that live in extreme habitats
(extremophiles), such as hot springs, geysers,
volcanic hot pools, brine pools, black smokers
(hydrothermal vents)
• Unicellular
• Prokaryotic
• Autotrophic or heterotrophic
• Cell walls without peptidoglycan
Kingdom Archaebacteria
Morning Glory Pool in Yellowstone National Park – note the bright colors
from the archaebacteria growing in the extremely hot water.
Kingdom Archaebacteria
• Bacillus infernus
Some live in
temperatures
as high as
230° F
Kingdom Archaebacteria
• Archaebacteria can live
deep in the ocean near
hydrothermal vents
• There is no light, so
they carry out
chemosynthesis instead
of photosynthesis
Kingdom Protista
• Extremely diverse group
• Eukaryotic
• Most unicellular, some colonial, some
multicellular
• Autotrophic and heterotrophic
• Some with cell walls containing cellulose;
some carry out photosynthesis with
chloroplasts
Kingdom Protista
Euglena - autotrophic
Volvox – a colonial protist
A slime mold
Amoeba - heterotrophic
Kingdom Fungi
• Eukaryotic
• Most are multicellular
• Heterotrophic, decomposers- feed on dead or
decaying organic matter, digest food externally
and then absorb the nutrients
• Cell walls made of chitin
Kingdom Fungi
Stilton cheese
Bread mold
Kingdom Plantae
•
•
•
•
•
Eukaryotic
Multicellular
Autotrophic
Cell wall of cellulose; chloroplasts present
True tissues
Kingdom Plantae
Kingdom Animalia
•
•
•
•
•
Eukaryotic
Multicellular
Heterotrophic
No cell walls, no chloroplasts
True tissues
Kingdom Animalia
Flatworm
Sponge
Jellyfish
Octopus
Coral snake
Bear
Some Animal Phylums
•
•
•
•
•
•
Porifera- sponges
Cnidaria- hydra, jellyfish, corals, sea anemones
Platyhelminthes (flatworms)- planarians, flukes, tapeworms
Nematoda (roundworms)
Annelida (segmented worms)- earthworm
Mollusca- bivalves (clams, oysters), gastropods (snails, slugs),
cephalopods (squid, octopus)
• Echinodermata- starfish, sea urchins, sea cucumbers
• Arthropoda- crustacea, spiders, insects
• Chordata- fish, amphibians, reptiles, birds, mammals
Organ Systems
•
•
•
•
•
•
•
Integumentary
Skeletal
Muscular
Respiratory
Digestive
Circulatory
Lymphatic
•
•
•
•
Excretory
Nervous
Endocrine
Reproductive
Symmetry
• Symmetrical
~ animal can be cut into 2
equal halves.
• Asymmetrical
~body patterns cannot be
divided into equal halves.
• Human Brain
• AMOEBA
Anatomical Terms
•
•
•
•
•
•
•
•
•
•
Cephalic- concerning the head
Caudal- concerning the tail
Anterior- toward the front; forward
Posterior- toward the rear; farther back
Dorsal- on or near the upper surface; back
Ventral- on or near the lower surface; front
Lateral- on or toward the side
Medial- on or toward the middle
Midline (median)- divides into right and left
Transverse- crosses perpendicular to midline
p446
At least 95% of the
more than 1,367,000 species
of animals are invertebrates.