Download Disease Unit Review

Disease Unit Review key
Sections 19.1, 19.2, 19.3, 40.1, and 40.2
Section 19.1: Bacteria
1. Draw or name the major parts of a bacteria cell.
- Cell membrane
- Cell wall (2 or 3)
- DNA or RNA (plasmid)
- Cytoplasm
2. What two kingdoms are prokaryotes split into, and how do those two kingdoms differ?
Archaebacteria and Eubacteria
Differences: archaebacteria live in extreme environments
Eubacteria have peptidoglycan in their cell walls
DNA in archaebacteria is more like eukaryotic DNA
3. Describe the four ways that prokaryotes are classified:
a. Shape (cocci [round], bacilli [rod shaped], spirilli [spiral])
Can also be in staphylo (cluster) or strepto (long chain) arrangement
b. Movement (can move using flagella, or can’t move at all)
c. Gram Stain- Gram Positive bacteria have two cell walls, and turn purple using
a gram stain. Gram Negative bacteria have three cell walls, and turn pink.
d. How they get energy- can be photoautotrophs, chemoautotrophs, or
heterotrophs (see definitions below).
4. Define the following methods of obtaining energy, and give an example of bacteria
that do each:
a. autotrophs: Make their own food using resources in the environment.
Ex: cyanobacteria and archaebacteria
b. photoautotrophs: Make their own food using light energy, similar to
photosynthesis. Example: cyanobacteria (blue green algae)
c. chemoautotrophs: Make their own food using chemicals in the environment.
Example: archaebacteria that live in deep sea vents.
d. heterotrophs: Rely on matter of other organisms for energy. Example: flesh
eating bacteria
Section 19.2: Viruses
5. Draw or list the main parts of a virus.
- protein coat (capsid)
- DNA or RNA (retroviruses have both)
6. List four reasons why viruses are not considered to be living things:
a. they are parasites, needing a host to get energy
b. they have no control over their movement
c. they can’t reproduce on their own
d. no nucleus, cytoplasm, organelles, or cell membrane
7. What is the difference between temperate and virulent viruses?
Temperate viruses do not make you very sick, and do not act quickly. They often
stay in the lysogenic cycle. Virulent viruses act very quickly, making you sick
and entering the lytic cycle right away.
8. Define viroid and prion, and explain what they do.
Viroid: genetic material on the run! DNA or RNA without a protein coat that
hijacks cell enzymes to reproduce itself.
Prion: protein on the run! Proteins that use ribosomes in cells to reproduce
themselves, making large protein plaques- mad cow disease is the accumulation
of protein plaques in the brain.
9. Draw or describe the lytic and lysogenic cycles of viral reproduction. How does the method of viral
reproduction relate to a virus’ virulence?
Lytic cycle: Virus injects its DNA or RNA into host; the virus reproduces itself using the cell’s
organelles; within 1-2 days, the new viruses burst out of the cell and look for new cells to infect.
Lysogenic Cycle: Virus injects its DNA into host; DNA becomes part of host’s
DNA; Viral DNA reproduces every time cell divides.
Virulent viruses tend to use the lytic cycle right away, making the host immediately ill. Lysogenic
viruses can stay dormant, causing less severe, if any, illness.
Section 19.3: Diseases Caused by Bacteria and Viruses
10. Explain two ways that bacteria cause disease.
a. Releasing toxins (botulism, strep throat)
b. Feeding off host tissues (flesh eating bacteria, tuberculosis)
11. What are antibiotics, and how do they treat bacterial infections?
Antibiotics are toxins produced by bacteria to kill other bacteria in a competition for space on a host.
They kill each other by disrupting cell walls. We have engineered bacteria to produce these
antibiotics in large amounts, and to fight the bacteria we want them to. When you have a bacterial
infection, you swallow or are injected with antibiotics to kill the infection inside of you.
12. Why can’t antibiotics be used on viruses?
Antibiotics disrupt the cell wall of bacteria; since viruses don’t have cell walls, antibiotics don’t
work.
13. What are vaccines, and how are they used to treat viral and bacterial disease?
Vaccines are weakened or dead versions of a bacteria or virus. When we are injected with them, our
immune system creates and stores antibodies to fight the disease when we get it for real.
14. For the following diseases, list what organism/parasite them and how they are prevented/treated:
a. Influenza – Virus; vaccine to prevent, anti-viral medications to treat
b. Staph infection- Bacteria; vaccine to prevent, antibiotics to treat
c. E. coli food poisoning- Bacteria; vaccine to prevent, antibiotics to treat
d. Mad cow disease- Prion; no prevention or treatment
e. Malaria- Protist; does not respond to vaccines, antibiotics, or anti-virals
f. Common cold- Virus; vaccine to prevent, anti-viral to treat
g. HPV/Genital Warts- Virus; vaccine to prevent, anti-viral to treat
f. Syphilis- Bacteria; vaccine to prevent, antibiotic to treat
Section 40.1: Infectious Disease
15. List the four major causes of disease:
a. Bacteria and Viruses
b. Protists
c. Worms
d. Fungi
Section 40.2: The Immune System
16. Describe four parts of your body’s first line of defense:
a. skin: provides a protective barrier against pathogens
b. mucus: traps pathogens and other foreign objects in nose, throat, and eyes.
Cilia (tiny hairs) push the pathogens forward to be expelled from the body.
c. Digestive fluids: stomach is very acidic, killing pathogens trying to live there.
d. Enzymes in body fluids: lysozyme in blood and lymph fluid kills pathogens
trying to live there.
17. Describe how the inflammatory response, your body’s second line of defense, works.
When the first line of defense is broken, the inflammatory response occurs. Blood carries white
blood cells to the scene to engulf pathogens. Your body raises its temperature (fever) to kill bacteria
that can’t live above 98.6 degrees. The area of infection gets red, swollen, and painful because of the
blood flow and death of white blood cells who are battling the bacteria.
18. What are interferons?
Cells that have been infected with a virus release interferons, which are proteins that interrupt viral
reproduction and infection of new host cells.
19. What triggers cell-mediated versus humoral immunity?
Cell Mediated immunity is triggered by cells infected by viruses, or cells that have become
cancerous. Humoral immunity is triggered by antigens in the blood stream and other bodily fluids.
20. Describe the process of humoral immunity, including the action of Memory B Cells,
Plasma Cells, and Antibodies.
B Cells bind to antigen, and become either Memory B cells or Plasma Cells. Memory B Cells are
stored in lymph nodes, while Plasma Cells go into battle. Plasma Cells create antibodies that attack
and destroy antigens. If you are infected with the same antigen again, the Memory B Cells divide to
become Plasma Cells, who immediately have the antibodies to kill the antigen.
21. Describe the process of cell-mediated immunity, including the actions of
Killer T, Suppressor T, Memory T, and Helper T Cells.
The Helper T cells activates Killer T cells, who find and destroy infected by breaking through their
cell membranes. Helper T cells also create Memory T cells to react faster to the same infection next
time. Finally, Suppressor T cells turn off Killer T cells so they stop killing.
22. Circle the following immune functions that are non-specific:
First line of defense, inflammatory response, cell-mediated immunity, humoral
immunity, interferons
Non Specific = first line of defense, inflammatory response, interferons