VIRUSES
VIRUSES
health.howstuffworks.com/light-virus.htm
A virus is a sub-microscopic infectious agent that is unable to grow or reproduce outside a host cell. Viruses infect all cellular life. When found outside of host cells, viruses exist as a protein coat or capsid, sometimes enclosed within a membrane.
The capsid encloses either DNA or RNA which codes for the virus elements.
Viruses spread in many ways; different species of virus use different methods. For example, plant viruses are often transmitted from plant to plant by insects that feed on sap, such as aphids, while animal viruses can be carried by blood-sucking insects.
The capsid encloses either DNA or RNA which codes for the virus elements.
Viruses spread in many ways; different species of virus use different methods. For example, plant viruses are often transmitted from plant to plant by insects that feed on sap, such as aphids, while animal viruses can be carried by blood-sucking insects.
These disease-bearing organisms are known as vectors. Influenze viruses are spread by coughing and sneezing, and others such as norovirus, are transmitted by the faecal-oral route, when they contaminate hands, food or water. Rotavirus is often spread by direct contact with infected children.
posted by Maverick,Jonathan,Nicholas,Yaqzan @ 5:35 PM
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