Download Microbiology Review Guide Answers

Microbiology Review Guide Answers
Viruses
1. A virus is a small pathogen which causes many diseases.
2. Viruses are non-living because they don’t carry out life processes such as
metabolism, growth, & development. All are parasitic – require hosts.
3. True: Viruses are specific as to what type of host or tissue they infect.
4. Ebola, AIDS, colds, influenza, chicken pox, polio, etc. are all viral diseases.
5. Interferon is a protein produced by the body that interferes with viral
replication.
6. Ebola kills its victims too quickly so it is unable to spread very far.
7. Viruses consist of a nucleic acid (DNA or RNA) wrapped in a capsid (protein
coat).
8. Viruses are classified by the type of nucleic acid they consist of, shape, mode
of transmission, etc.
9. People don’t get sick every time they encounter a virus because they may be
immune (have antibodies), they may have destroyed it with other defenses,
such as stomach acid, it may be a virus that does not infect humans . . .
Bacteria
1. Bacteria belong to the Archaebacteria or Eubacteria Kingdoms.
2. Bacteria are classified by shape, arrangement, gram stain reaction, oxygen
requirements, colony color/appearance, etc.
3. See diagram on Bacteria WS & Quiz
4. An endospore is an adaptation for protection, it is a structure that allows the
bacterial cell to remain dormant when environmental conditions are
unfavorable & when conditions improve, the cell will resume normal
functioning.
5. Obligate aerobes require oxygen for energy, obligate anaerobes do not use
oxygen and may be harmed by it, facultative anaerobes can use oxygen when
available but can also use fermentation for energy when oxygen is not
available.
6. Most bacteria eat carbon based compounds such as fat, protein, sugar, or
blood.
7. Parasitism is a relationship in which one organism benefits and the other is
harmed; Mutualism is a relationship in which both organisms benefit.
8. Bacteria are able to convert nitrogen in the air into soil compounds that plants
can use; they are used to make many food products, including yogurt,
cheese, pickles, etc., they aid in digestion, are used for vaccines, wrinkle
treatment, leather tanning, producing beer & wine, genetic engineering of
human hormones etc. Bacteria can also be harmful because they cause food
spoilage & disease.
9. Most bacteria prefer warm, dark, moist environments with the correct oxygen
requirements & a food source.
10. Binary fission is a form of asexual reproduction – identical bacteria are
produced; Conjugation is a form of sexual reproduction in which bacteria can
share their genetic material & therefore pass on mutations.
Labs
1. Agar in a Petri dish provides a food source for the bacteria.
2. Bacteria are mixed with water when making a smear to dilute them so that
individual cells can be seen.
3. Heat fixing bacteria helps them to stick to the slide & not wash off during the
addition of chemicals & rinsing.
4. True: the gram reaction is based on cell wall chemistry.
5. A gram + streptococcus would be a purple chain of spheres.
6. True: A colony consists of bacteria that are genetically alike.
7. ------- 8. ------- 9. ------Spread of Disease
1. Direct Contact
2. Botulism
3. Food
4. Salmonella
5. Airborne droplets
6. Anything that can carry & transmit disease; Lyme disease – deer tick; AIDS –
dirty needle
7. Boil water, filter water, chemically treat water, cook food thoroughly, wash
hands, refrigerate or freeze perishables . . .
8. Many different strains exist & they mutate rapidly.
9. Disinfect objects/surfaces; don’t share personal hygiene items; wear shower
shoes, etc.
Defenses Against Disease
1. Helper T cells – identify invaders & alert the immune system; killer T cells
destroy infected body cells by using powerful chemicals; memory cells – store
information for preparing antibodies; B cells – produce antibodies
2. Fever speeds up the rate of tissue repair & slows down pathogen growth
3. Stomach acid kills many swallowed pathogens
4. A vaccination is an injection of dead or inactivated pathogens that cause the
body to produce antibodies to that particular pathogen = immunity
5. Mucus, skin, saliva, interferon, complement, phagocytes, etc. are all physical
or chemical defenses against pathogens
6. Histamine is the substance produced by white blood cells that causes
inflammation
7. Interferon is a non-specific chemical defense that “kills” viruses
8.
Passive Immunity
Active Immunity
Where antibodies made
Someone else
Your own body
How acquired naturally
Placenta/Breast milk
Exposure to pathogen
How acquired artificially
Injection of antibodies Vaccination
How long it takes to develop Works immediately
~1 month or so
How long immunity lasts
Short time – few
Long time – months,
weeks
years or permanent
Are memory cells involved? No
Yes
Parasites
1. Tapeworm
2. Schistosoma (Swimmer’s Itch)
3. Trichina
4. Hookworm
Protists
1. False – All protists are not multicellular; most are unicellular
2. True
3. True
4. False – Sporozoans are animal-like protists that cannot move
5. Cilia = small hairs in large numbers & flagella = long, whip-like structures only
1 or 2 total.
6. Ameoba
7. Malaria, African Sleeping Sickness, Chagas Disease – bite of infected
arthropod
8. True
9. Euglena has no cell wall and can move = animal-like BUT also has
chlorophyll to make its own food = plant-like
10. They supply ~75% of the world’s oxygen