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Classification and the 6
kingdoms
I. Taxonomy
A. Branch of biology that specializes in
classifying organisms into a series of
groups called TAXONOMY.
B. Classification System
2. KINGDOM : (A group of related Phyla)
a. Largest classification taxon
b. Has the MOST organisms
3. PHYLUM : (A group of related classes)
Called division when referring to plants
4. CLASS : (A group of related orders)
5. ORDER : (A group of related families)
6. FAMILY : (A group of related genera)
7. GENUS : (A group of related species)
8. SPECIES :
a. Smallest taxon
b. Has the LEAST # OF organisms
c. Members of a species to be able to
interbreed and produce fertile offspring
C. If an organism is in the same phylum
then they are in the same KINGDOM .
What if they were in the same family, what
else would they be in that is the same?
DOMAIN KINGDOM PHYLUM CLASS
ORDER
D. Naming Organisms
1. Scientific names are made by using the GENUS and
SPECIES.
a. The genus is always written first and is
capatilized.
b. The species is always written second and is
lowercase
c. Both the genus and species are italicized
2. Binomial nomenclature:
a. Uses TWO names (genus and species) to identify the
organism.
b. Carlous Linneaus gave us binomial nomenclature.
c. Acer rubrum (Acer=genus) (rubrum=species)
3. Trinomial nomenclature:
a. used when organisms are divided into
subspecies or varieties
b. The first two names are still the GENUS
and SPECIES but the third name is the
subspecies or variety
c. Example: Haliaeetus leucocephalus
washingtoniensis; (Haliaeetus=genus)
(leucocephalus=species)
(washingtoniensis=subspecies)
4. Scientific names tell you if two organisms
are closely related.
a. If the scientific names are Acer rubrum
and Rana rubrum, are these two
organisms closely related? NO
b. If the scientific names are Acer rubrum
and Acer saccharum, are these two
organisms closely related? YES
c. If you find an unknown organism, the best way
to tell if the unknown organism is related to the
known organism is to look at DNA comparisons
d. Scientists also use diachotomous keys to
determine what species an unknown organism
is.
i. It is a series of QUESTIONS that leads you to
the organism’s name
ii. you always start back at question one
II. Viruses
A. Do not belong to a kingdom because they are
not considered to be LIVING organisms
B. Examples of Viruses: flu, chicken pox, HIV,
cold sores, and some can cause cancer
C. The biggest viruses are 1/100 the size of
prokaryotic cells (bacteria/without a nucleus or
membrane bound organelles). Most bacteria
are even smaller than half the size of a
prokaryotic cell.
D. Considered to be non-living because
they CAN”T :
1. Grow
2. Develop
3. Obtain energy
4. Reproduce on their OWN; viruses must
use a HOST cell to reproduce
E. Virus classification or names come from:
1. The TYPE OF CELLS they affect; ex:
adenovirus affects the adenoids in the throat
2. The DISEASES they cause; Ex: poliovirus
causes polio
3. Some of the viruses are similar and are
therefore given a number as part of their name
4. BACTERIOPHAGES are viruses that affect
bacteria
F. Virus Structure
1. Contain an inner core of NUCLEIC ACIDS
a. Viruses either have DNA or RNA but
NEVER both
2. CAPSID : protein coat that surrounds the nucleic acid;
the way the proteins are arranged determines:
a. The SHAPE of the virus
b. The cells the virus can affect
c. The WAY the virus infects the cells
3. ENVELOPE: Some, but not all, viruses have an
envelope that acts like a plasma membrane
G. LYTIC Cycle (Virus Reproduction)
1. Viruses take over the genes of the host
cell
2. They use the genes to make more viral
genes and viral protein
3. This continues until the cell is so full of viruses
it actually BURSTS intern killing the host cell
and releasing more viruses into the body
4. Viruses can infect:
a. PLANTS
b. animals
c. bacteria
5. The only way a virus can infect a living cell is if a
receptor site on the host cell MATCHES that of
the virus.
a. Specific cells are only vulnerable to certain
VIRUSES
b. Ex: Tobacco mosaic virus can only invade the
leaves cells in a tobacco plant (The reasons
dogs don’t catch your colds)
6. Antibiotic DO NOT kill VIRUSES because Anti
means against and bio means life so against
life…viruses are non-living, you can’t kill
something that isn’t alive
There is a six-kingdom classification
system:
1. Kingdom Archeabacteria
2. Kingdom Eubacteria
3. Kingdom Protista
4. Kingdom Fungi
5. Kingdom Plantae
6. Kingdom Animalia
Kingdoms 1 and 2 used to be combined
into Kingdom Monera
III. Kingdom Monera (Bacteria/Prokaryotic
Cells)
A. Now divided into Archeabacteria and
Eubacteria
B. Reproduce by binary fission
C. All cells in kingdom monera are
prokaryotic meaning they are lacking a
nucleus and membrane-bound organelles
and their DNA is found in the cytoplasm
D. All prokaryotes contain a cell wall
E. Most widespread and numerous
organisms on Earth
F. Kingdom Archaebacteria
1. Has a different composition to their cell
wall than Eubacteria
2. Genes are more similar to eukaryotes
than to eubacteria
3. oldest living organisms
4. Live in harsh environments: Hot sulfur
springs, deep sea vents on the ocean
floor, Great Salt Lakes, and intestines of
mammals
5. Autotrophic and Heterotrophic
6. Can tell all the archeabacteria are
related by their RNA sequencing
G. Kingdom Eubacteria
1. Have a different composition to their cell
wall than Archeabacteria
2. Classified according to their shape and
reaction to Gram staining
3. Eubacteria Metabolism
a. heterotrophic (must eat other
organisms)
b. parasitic (Live off of other organisms)
c. decomposers (Eat dead and decaying
organisms)
d. Autotrophic (make their own food)
i. Photosynthetic Autotrophs: Contain
chlorophyll; Use the sun’s energy to
make food through photosynthesis ex:
Cynobacteria
ii. Chemosynthetic Autotrophs: Break down
nitrogen and Sulfur to make organic
compounds (glucose )
G. Bacteria Pros and Cons
1. Helpful Bacteria
a. Most bacteria is important and beneficial
b. Nitrogen-fixing bacteria: live in the roots of plants and
help it to obtain nutrients
c. Break down dead things
d. Put oxygen back in the soil by
photosynthesis
e. FOODS: Pickles, Yogurt, Cheese
f. Antibiotics : neomycin and erythromycin kill other
bacteria; Remember antibiotics can NOT be used to kill
viruses, because they are non-living. They only kill
bacterial infections
g. Probiotics live in the intestine and make vitamins, help
with absorption, enhance the immune system
2. Harmful Bacteria
a. endospores: Cause botulism or
tetanus
b. Lyme disease, strep throat
c. Biofilms cause cavities
IV. Kingdom Protista
A. Called the “_catch all ” kingdom because it contains
many organisms that don’t fit into the other kingdoms
B. The most DIVERSE kingdom
C. ALL are eukaryotic (Contain a nucleus and membrane
bound organelles)
D. Can be heterotrophic or autotrophic, unicellular or
mulitcellular, large or microscopic
E. Contain contractile vacuole that pumps excess water
out of the cell: important for protests that live in fresh
water (hypotonic-water will move into the cell and the cell
will burst)
F. Animal-Like Protists
1. Called protozoans
2. unicellular
3. Ex: paramecium (use cilia to move) , amoeba
(shapeless and doesn’t have a cell wall; it moves
by pseudopods which stick out of the cytoplasm)
4. Other Protozoans may move by cilia or flagella
5. Many protozoans are parasites and cause
disease like malaria
G. Plant-Like Protists
1. Contain chlorophyll and are autotrophic
so they carry out photosynthesis
2. Ex: Algae
a. they don’t have roots, stems, or leaves
like plants so they are not a plant
b. May contain red, brown, or golden
pigments
c. Size ranges from unicellular to a mile
long
3. Ex: Diatoms
a. Made of a glass-like outer shell
b. When the protist dies the glass shell
sinks to the bottom and collects.
c. This collection is called diachotomous
earth which is used in abrasives like
toothpaste and cleaners and in
insecticides
4. Other examples: euglenoids, goden
algae, green algae, brown algae, and red
algae
H. Fungus-Like Protist
1. Decompose dead organisms
2. Able to move for part of their life
cycle
3. Ex: slime molds, downy mildews,
and water molds
V. Kingdom Fungi
A. Grow anywhere that has moisture
B. Mostly multicellular (yeast are the only
unicellular fungi)
C. Used to be classified as plants but they
don’t contain chlorophyll so they are not
producers…instead they are consumers
meaning they have to eat, yes, fungi DO
eat They are heterotrophic
D. Fungi use extracellular digestion to eat
1. hyphae are threadlike structures sent
out into the food source
2. Hyphae release enzymes that break
down food until it is small enough to cross
the cell walls into the hypahe
E. Cell wall made of chitin, a complex
carbohydrate) (Remember plants have a
cell wall made of cellulose …a
polysaccharide)
F. Fungi Heterotrophs
1. decomposers : Break down dead and
decaying matter
2. Saprophytes like mushrooms break down dead
organic matter
3. Parasites like ringworm and athlete’s foot
4. lichens: A mutualistic (both
benefit)relationship between fungus and green
algae; They are important because they break
down rocks into soil so plants can grow and they
put nutrients into the soil when they die and
decompose
G. Fungi Reproduction
1. Asexual Reproduction
a. Yeasts
b. budding: organism grows from the parent
and then breaks off
c. fission: the yeast splits in half to form two
yeast cells
2. Sexually:
a. Mushrooms
b. Spores called basidiospores are produced in the
cap of the mushroom
c. Spores are produced by meiosis so they are
haploid when two spores meet and germinate
to have a baby mushroom
3. Both Sexually and Asexually
a. Bread molds and most fungi
b. Sporangium (a specialized hyphae) produce
asexual spores
c. The sporangium release these spores which can
grown into more sporangia
d. if conditions are unfavorable bread molds
reproduce sexually
i. two hyphae fuse together to forma
zygospore
ii. the zygospores has a thick cell wall
and can remain dormant until
conditions become favorable for
germination
H. Fungi Good or Bad?
1. Benefits
a. Food: mushrooms, yeasts make bread (through
alcoholic fermentation), cheese
b. Medicine (Penicillium) Antibiotics to kill
bacteria…NOT VIRUSES
2. Harmful
a. Destroy timber and crops each year
b. Plant disease called rusts and smuts
c. Some spores can be fatal if inhaled
(black mold)