Chapter 18.1Chapter 18.1Intro to VirusesIntro to Viruses

By By

Krista and CalebKrista and Caleb

Mydoom Virus

What is a virus?

Viruses are made of 3 parts.

1)Genes made from DNA or RNA.

2)Protein coat for protection.

3)(sometimes) a layer of fat.*

They do not have the ability to sustain life (on their own).

How a Virus Works

The virus reproduces its self within a cell.

It takes over a host cell*

Then moves to another cell*

They then move to the mRNA

Two cycles of virusesTwo cycles of viruses1) Lytic Cycle 1) Lysogenic cycle

Breakdown of cycles Lytic Begins cycle lytic attaches prophage is realesed replication detaches from DNA Cell bursts and starts over

Lysogenic• Begins cycle• lytic attaches• prophage is realesed• replication• cell undergoes a split • Two+ infected cells are

made

SpreadingSpreading

Bodily fluids (blood)

Sneezing/coughing

Contact

Stopping the spreadFrequent handwashing

Vaccination

Works Cited

Campbell, Neil A. Biology. San Francisco, CA: Pearson/Benjamin Cummings, 2005. Print.

"File:

Phage2.JPG." Wikipedia, the Free Encyclopedia. Web. 06 Feb. 2011. <http://en.wikipedia.org/wiki/File:Phage2.JPG>.

"Viruses and Bacteria." NetDoctor.co.uk - The UK's Leading Independent Health Website. Web. 06 Feb. 2011. <http://www.netdoctor.co.uk/health_advice/facts/virusbacteria.htm>.

"What Is a Virus?" THE MEDICAL NEWS | from News-Medical.Net - Latest Medical News and Research from Around the World. Web. 06 Feb. 2011. <http://www.news-medical.net/health/What-is-a-Virus.aspx>.