Transcript microbes cause disease!!

Messana
Science 8
Chapter 25
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= Microorganism, Microscopic Organism
Protists
Bacteria
Virus
Parasite
Found EVERYWHERE!!...water, surface of living
things, inside living organisms
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Caused by a microbe entering a place in the
body where they aren’t supposed to be
Organism experiences impaired function
Show symptoms = your body’s response to
disease (fever, vomiting, joint pain, skin
condition, diarrhea, etc.)
Can be infectious/communicable OR
non-infectious/non-communicable
E. Coli
O157:H7 can
make you very
sick.
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Single celled organisms – ALIVE!
Very small, Need microscope to see
Prokaryotic
Can be found on most materials and
surfaces – Soil, Water, Air, etc.
Billions on your skin and in your
body’s digestive track right now!
Harmless bacteria on
the stomach lining
Streptococcus can
cause strep
throat.
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Different shapes = sphere, rod, spiral
Have cell membrane, cell wall, & capsule
Cytoplasm contains genetic material floating
freely + ribosomes (no nucleus or other
organelles)
Has flagellum & cilia
Can move, reproduce, eat, etc.
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Harmful Bacteria = Germs, Pathogens
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Cause disease by releasing toxins into body
Toxins are the waste products from bacteria
Bacterial infections  fever, swelling, rash
Treat with ANTIBIOTICS!
Helpful Bacteria:
◦ Eat other more harmful substances
◦ Help plants and animals release nutrients to be
used by organism
◦ Digest food in your stomach
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VERY small!
Contains protein coat = CAPSID
Contains DNA or RNA
NOT A LIVING CELL!!
Can’t reproduce, eat, move, or maintain
homeostasis
Try to get inside HOST CELL to reproduce
Must fit cell membrane like “lock and key”
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If virus finds suitable living host
cell…
◦ DNA or RNA directs host
cell to make copies of
virus particle
◦ Copies of virus cause host
cell to EXPLODE!
◦ Viruses go on to affect
other cells
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Shaped life on Earth
Cause disease in plants & animals
Affected evolution by redistributing
genes
Can protect organisms from
environmental contaminants
Can’t treat viral infections with
anything – have to run their course
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An organism that has a harmful relationship
with a host organism
Parasite lives on or in the host
Slowly weakens or kills host quickly
EX: protists, bacteria, ticks, tapeworms,
heartworm, mites, fleas, athlete’s foot, fungi,
invertebrate insects
Are you ready for these pictures!?
 Transfer
sun energy into
energy that can be used by
cells
Break
down
materials in
Dead/Decaying
organisms
for reuse.
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LIVE ON HOSTS, may not affect host OR may
be HARMFUL to host.
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http://www.mixbook.com/photobooks/nature/producers-consumers-anddecomposers-3724805
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J:\The Parasite Picture Gallery.mht