Viruses We will review the characteristics of viruses

Herpes simplex virus cold sores (Type 1) or genital herpes (Type 2)

Human papilloma virus genital warts and cervical cancer

Hepatitis B virus hepatitis and cancer of the liver

Are viruses alive? • Virus – Not a cell – Genetic material surrounded by

Let’s Compare: Viruses Prokaryotes (bacteria) No Yes Reproduction Only in a cell Yes Genetic

Dengue Virus • • • Spread by mosquitoes Mostly tropical areas No cure High

Rabies Virus • • Spread by bite of infected animal Infects mammals Preventable through

Foot-and-mouth Disease Virus • Infects animals with hooves (cows, deer, sheep, pigs) • Not

Smallpox Virus (Variola) • Infects humans • Vaccines have almost eliminated smallpox • Somalia,

Making the virus • Cut along solid lines • Fold along dotted lines •

Summary: Is a Virus Alive? • • Do they reproduce? Do they have metabolism?

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Viruses We will review the characteristics of viruses in order to determine whether or not viruses are alive.

Relative size of a virus

Varicella zoster virus chickenpox

Variola virus smallpox

Poliovirus polio

Rhinovirus common cold

Adenovirus respiratory illness

Influenza virus (such as H 1 N 1) flu

Human immunodeficiency virus AIDS

Herpes simplex virus cold sores (Type 1) or genital herpes (Type 2)

Human papilloma virus genital warts and cervical cancer

Hepatitis B virus hepatitis and cancer of the liver

Rabies virus rabies

Ebola virus Ebola hemorrhagic fever

Dengue virus Dengue fever

Bacteriophage attacks bacteria

Viruses We will review the characteristics of viruses in order to determine whether or not viruses are alive.

Are viruses alive? • Virus – Not a cell – Genetic material surrounded by protein – Can only reproduce inside of a cell – No metabolism – No homeostasis

Let’s Compare: Viruses Prokaryotes (bacteria) No Yes Reproduction Only in a cell Yes Genetic Code DNA or RNA DNA Mutation only Yes Use of energy No Yes Response to stimuli No Yes Homeostasis No Yes Structure Cellular organization Growth/Develop

Dengue Virus • • • Spread by mosquitoes Mostly tropical areas No cure High fever (up to 105°) Rash over most of body Severe headache Pain behind the eyes Severe joint and muscle pain Bleeding under the skin

Rabies Virus • • Spread by bite of infected animal Infects mammals Preventable through vaccination Treatable if caught early Flu-like symptoms Delirium Hallucinations Death

Foot-and-mouth Disease Virus • Infects animals with hooves (cows, deer, sheep, pigs) • Not in US, but England Europe have cases • Mutates often • Lesions on tongue, nose, mouth and in between toes • High fever • Extremely contagious, but not to humans

Smallpox Virus (Variola) • Infects humans • Vaccines have almost eliminated smallpox • Somalia, Nigeria and Afghanistan are showing outbreaks • Flu-like symptoms • Full body rash • Blisters

Making the virus • Cut along solid lines • Fold along dotted lines • Tape together most of the shape • Add genetic material (~5 meters of yarn) before taping shut

Summary: Is a Virus Alive? • • Do they reproduce? Do they have metabolism? Are they made of cells? Do they have heredity? • Are they living or nonliving?