Virus+AG

7.1 (p.122-124) and Avian Flu p. 125

Why are viruses not exactly living or nonliving? Viruses bridge the gap between living and nonliving things. Outside a host, viruses are essentially chemicals that can be stored on a shelf. Viruses replicate inside cells and appear to be alive at this time.

Give some examples of diseases caused by viruses. Avian Flu, mad cow disease, JCD and bovine spongiform encephalopathy.

What is the basic structure of a virus? (The two parts and their function) A virus has two parts: an outer capsid composed of protein units and an inner core of nucleic acid. Both are either composed with either DNA or RNA.

Why are viruses like microscopic pirates? They command the metabolic machinery of a host cell

Why are viruses considered parasites? Viruses live inside other living things and feed off of their existence like parasites do.

Why are viruses considered OBLIGATE parasites? Because viruses must replicate inside a living cell.

Why do viruses ALWAYS cause disease? A virus relies on the host’s enzymes and ribosome for its own reproduction, the reproduction causes for the body’s illness.

How do viruses "emerge" and "spread" each year? Give examples. Viruses emerge by being transported from one location to another where it has not been before. They spread through the body’s germs to other patrons eventually causing the virus growth to increase. Viruses can also be spread by way of insects that require massive efforts to control the vector population such as the West Nile virus.

What is a virus vector? Give examples, Many viral diseases are transmitted by vectors, usually insects, that carry diseases from an infected individual to a healthy individual. If I virus transmitted by a rare species of mosquito can now be transmitted by a more common species.

What is the relationship of bird flu to birds? Birds can become infected by coming into contact with the saliva, feces, or mucus of another infected bird.

How does bird flu infect humans? When a human is infected with the human flu and then comes into contact with the avian flu and the two viruses could meet in the person’s body and swap genes with each other. Also if the two viruses infect a different host species and swap their genes in that host species.

What is a pandemic? A pandemic is when a virus is spread into and with another virus and causes them to spread and create illness. Why is there fear that bird flu could cause a pandemic? The fear is that the virus would become a hybrid virus and spread to become infectious, fatal and easily transmitted from person to person.

What action can we take to prevent bird flu pandemic? There are no current vaccinations but several drugs are being trialed and have produced mixed results. Also to be more careful with the spread of germs and interaction with the wildlife animals who might contain a virus.