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• Name some examples of viruses and the diseases that they cause.
• Explain how viruses replicate and survive within the body.
• Describe how RNA interference prevents virus replication.
• Describe potential applications of RNA interference.

Check your understanding with the Virus Wars Video Quiz.

Learning Points: 

Here are some of the main ideas that students should take away from this video:

• A virus replicates and survives by taking control of the replication mechanism within a cell and producing more copies of the virus. When a virus injects its genetic code into an invaded cell, the cell uses the code to build more viruses, which eventually burst through the cell membrane. The cycle continues as the new viruses attack other cells.
• The human body develops immune responses to defend against viral attacks. When a person gets sick with a virus such as the flu, the virus succeeds in replicating at first, but eventually the immune system learns to recognize and destroy the invaders.
• One type of immune response is RNA interference (RNAi)—which uses dicer proteins to identify viral RNA—was recently discovered in plants and some animals. Dicer proteins identify double-stranded RNA, which often indicates the presence of a virus, and chop it up. The cells use the RNA pieces, which are instructions for replicating the virus, to identify and stop the formation of new viruses.
• Scientists can use RNA interference to turn off one gene at a time in order to study the effects on organisms.
• Scientists do not yet know if human cells naturally fight viruses with RNAi. However, it may be possible in the future to use RNAi to treat human health problems. For example, scientists might be able to find a way to use RNAi to deactivate cancer-causing genes and genetic disorders.