viruses are they living things?!?. review which correctly identifies the organization of living...
TRANSCRIPT
Viruses
Are they living things?!?
Review
• Which correctly identifies the organization of living things from least complex to most complex?
• A. Community, Organism, Cell, Atom• B. Tissue, Ecosystem, Cell, Organ System• C. Molecule, Tissue, Population, Community• D. Atom, Organ, Community, Population
Review
• What 8 characteristics define living things?
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What do viruses look like?
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• All Viruses– Capsid
– DNA or RNA
• Some viruses– Envelop
Comparison with a bacteria
• Bacteria– Made up of cells
– Get energy (metabolize)
– Respond to stimuli
– Reproduce asexually
– Evolve
• Virus– Not a cell--no cell
membrane, ribosomes
– No metabolism
– ?Response to stimuli?
– Reproduce using the cells machinery as a host
– Evolve
Bacteria vs. Viruses
• Bacteria can be treated with antibiotics that destroy the cell’s wall. – Ex. Penicillin to get rid of Strep throat!
• Would antibiotics work on a sore throat caused by the common cold virus?
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Virus Reproduction
• Lytic: Uses cell and destroys cell. • Lysogenic: Uses cell and hangs out inside until
the right time to strike!
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Chicken Pox
• Varicella virus• Lytic cycle--pox• Lysogenic cycle--can
remain dormant and come back as shingles.
• What does the vaccine do?
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Vaccines
• Trick your immune system into producing a response to an antigen and make antibodies.
• Can be for a virus or bacteria.
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What do antibodies do?
• Antibodies make it easier for your body’s immune system to recognize and destroy pathogens before you get “sick”
• “Memory”
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Why vaccinate? Why not just treat the symptoms?
• If there is no host, the virus may no longer be able to exist.
• Smallpox was eradicated in 1977 through a world-wide vaccination program.
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Types of Vaccines
• Live, attenuated– Chicken Pox– MMR– Polio “drink”
• Killed– Flu– Polio shot
• Component– Hepatitis
• Toxins– Tetanus – DPT (whooping cough)
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“Tricky” Vaccines
• Influenza--– Why do we have to get
a new one every year?
– Why doesn’t it always work?
• HIV--Why don’t we have one?
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Virus Question
• Peer edit:– How many characteristics of life did they mention?– How many characteristics of life did they relate to the
virus?– How many characteristics of life did they explain using
example from a virus why the virus does or does not display the characteristic?
– What could they add from what we talked about today to support 1-2 characteristics of life?
What makes a good open response?