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Viruses
What is a virus?
• Virus-A small nonliving particle that invades and reproduces inside a living cell
• Why are they nonliving again?
– Not made of cells
– Do not use energy to grow or respond to surroundings
– Cannot make food or produce waste
What are they? Cont…
• Viruses act like parasites
– Something taking advantage of another organism
• Host
– The organism being taken advantage of
• Viruses infect members of all 6 kingdoms
• Normally target a particular cell type
– Example: Cold-Cells of throat and nose
Naming Viruses
• Viruses are not alive
– No two-part name
• Virus animalis-Doesn’t exist
• Instead viruses are named after:
– The disease they cause-Polio
– Discoverers of the disease- Winter-Fittante Virus
– Location disease originated from -Ebola
What do they look like?
• Bacteriophage-bacteria eater
What do they look like? Cont…
• All shapes and sizes
– Brick shaped
– Bullet shaped
– Round
– Etc.
Structure
• Two parts
• Outer Coat-Protein coat
– Protection
– Attaching to host
• Inner Coat-Contains genetic material
– Information for making new viruses
Two Types of Viruses
• Active and Hidden
– Once a virus finds a cell they can attach to they lock on
– Invasion depends on type of virus
– Eventually, both types take over cellular machinery and use it to make copies of themselves
Type 1: Active Viruses
• Active
– Invasion
– Virus immediately begins to make new copies
– Cell bursts and virus invasion spreads
Type Two: Hidden Viruses
• Hidden (Cold Sores virus)
– Invasion
– Virus becomes part of the cell (Dormant)
– Can remain like this for a long time
– Assumes active state (see above)
• Dormant stage is believed to be ended by strong sunlight and/or stress (Cold sore virus)
Viruses in the Living World
• Ebola, Flu, AIDS, rabies
• Plant viruses deprive us of food
• But are they all bad?
– Not all
• We use some for gene therapy.
• Gene therapy-Modifying a disease on a genetic level
• Use virus to modify cell DNA
Gene Therapy Controversy
• Used to help restore normal cell function with a “good” invasion of viruses
• Example: Cystic Fibrosis-Patients don’t have genetic information for normal lung function
• However, we are modifying genetics of a person.
• God created us just as we are…are we playing god?
Gene Therapy Paper
• Write a one page, typed, persuasive paper that provides reasoning to answer the following:
• Is using gene therapy to cure diseases tampering with God’s creations?