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 Flu Attack: How a Virus Invades Your Body Video Clip 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 Binary Fission Video Clip 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.