Transcript Microbes_PP

Microbes
Unit 3: Week 1
Microbiology
 Microbiology explores
microscopic organisms
including viruses,
bacteria, protozoa,
parasites and some
fungi and algae.
 Each of these
organisms lack tissue
differentiation, are
unicellular and exhibit
diversity in form and
size.
Viruses
1.Nonliving particles
that are made of
nucleic acid (DNA or
RNA) and a protein
coat.
2.Need a host cell to
reproduce
 Flu Attack: How a Virus Invades Your
Body Video Clip
Viruses
 Viruses invade healthy
cells and use the
enzymes and
organelles of the host
cell to make more
viruses, usually killing
those cells in the
process.
Viruses
 Viral diseases are among the most
widespread illnesses in humans.
 These illnesses range from mild fevers to
some forms of cancer or other fatal
diseases.
 Transmission of viruses vary; some by
human contact and others through water
or an insect bite.
West Nile Virus
Viruses
3.Vaccines and
some anti-viral
drugs are used to
prevent the spread
of viral diseases.
Bacteria
1. Prokaryotic, single celled organisms
 Can live in a variety of places (with or
without oxygen, hot or cold, etc).
2.Bacteria reproduce through binary
fission, a form of asexual reproduction.
 Bacteria can grow and divide very rapidly.
Binary Fission
 Binary Fission Video Clip
Bacteria
 Antibiotics are used to inhibit the growth
of bacteria.
 Because antibiotics have been overused,
many diseases that were once easy to
treat are becoming more difficult to treat.
3.Antibiotic resistance in bacteria occurs
when mutant bacteria survive treatment
and give rise to a resistant population.
Fungi
1. Eukaryotic (have a nucleus),
nonphotosynthetic organisms and most
are multicellular heterotrophs.
2. Most can reproduce both sexually and
asexually, producing spores (this gives it
an advantage)
Fungi
 When the environment is favorable, rapid
asexual reproduction ensures an
increased spread of the species.
 During environmental stress, sexual
reproduction causes genetic
recombination, increasing the liklihood
that offspring will be better adapted to
new conditions.
Fungi
3. Can attack tissues of
plants and animals and
causes disease.
 Major concern for humans
because fungi not only
attack us, but also our
food, making fungi
competitors with humans
for nutrients.
Fungi
 Mold spores can
cause mild to
serious allergies in
some people.
Billions of mold
spores can become
airborne and may
then be inhaled,
triggering a reaction.
Parasites
1. An organism that feeds on another
individual, known as the “host” (either
live on or in the host’s body).
2. Natural selection favors adaptations that
allow a parasite to exploit its host
(anatomically and physiologically).
Parasites
 Ex. Tapeworms are so specialized for a
parasitic lifestyle that they do not even
have a digestive system.
 They live in the small intestine of their
host and absorb nutrients directly through
their skin.
Parasites
3. Infectious disease may also be caused by
animal parasites, which may take up residence
in the intestines, bloodstream or tissues.
Ewwww.
 Tapeworms are common in dogs and cats
(from fleas) and they can pass on to humans
(cucumber like seeds in poop-gross!!!).
 Many remedies exist to kill worms if you do
become infected.