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Viruses

Date:April 19, 2006 12:47 pm
Subject:Science
Word Count:277
Page Count:2


Viruses
The word virus means "poi-son" in Latin. Viruses are submicro-scopic
intracellular parasites that consist of either RNA or DNA, and a protective coat
of protein. It has caused countless diseases in vari-ous organisms. The term
virus was first used in the 1890s to describe agents that caused diseases that
were smaller than bacteria. The ex-istence of viruses was established in 1892,
when Russian scientist Dimity I. Ivanovsky discovered microscopic particles
later known as the tobacco mosaic virus. Over the years, scientists have debated
whether viruses are alive. Some scientists argue that the virus is lifeless. On
the other hand, other scientists argue that viruses are lifeforms and should be
classified into a kingdom. However, many sci-entists have agreed that things
must have seven characteristics of life to be considered alive. The character-istics
of life are all living things are composed of cells, all organisms are organized
at cellular and molecular levels, energy use, and response to the environment,
growth, reproduc-tion, and adaptation. From research and observa-tion,
scientists have found that vi-ruses can perform some of the life processes. They
found that viruses have organization, the ability to re-produce, and
adaptations. First, they found that viruses are generally organized and composed
of a nu-cleic acid core, either RNA or DNA, surrounded by protein. Next, they
found that viruses could reproduce. It does not reproduce by sexual or asexual
production, but by injecting its genetic material into the nucleus of a living
cell. Finally, they found out that viruses have adaptations. They have the
ability to mutate into different strains to resist man-made drugs. In short,
these are some views and facts about the virus. To this day, scientists are
still fiercely debating whether viruses are alive. Should we consider them alive
since they perform some life processes or simply consider them lifeless?

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