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Determine whether or not viruses are actually living organisms.

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Introduction

Rachel Davis S. Floyd English 103 Essay 1 11 May 2004 Essay I It is quite difficult to determine whether or not viruses are actually living organisms. They do not complete many of the same tasks that living organisms do, and yet it seems that they are much more than complex chemicals. Scientists still do not know much about the origin of viruses and do not yet fully understand how viruses are related to each other, or to other organisms. Currently, the scientific opinion is: viruses are not living organisms. Viruses are considered non-living because they do not use energy to grow or to respond to their surroundings, they are obligatory intracellular parasites, and most importantly they do not satisfy all the characteristics of living organisms. Viruses were originally distinguished from other infectious agents because they are especially small and filterable - a characteristic which many bacteria are unable to claim. Unlike these bacteria however, viruses have few or no enzymes of their own for metabolism. ...read more.

Middle

On the contrary, "most endosymbionts and parasites, are acutally multi-cellular eukaryotic animals that generally posses digestive, circulatory, nervous, excertory, and reproductive systems- and are highly specialized to live inside their hosts" (Tortora, 361). In short, even though parasites might only be able to live and also reproduce inside a host - much like a virus, it is evident that they are considered to be living organisms due to the complexity and simality of their structure to other living organisms. Dispite that, there are essential properties and characteristics which are associated with life. Virsuses, however, can not fully satisy all of them. "All living organisms are alike in these aspects: cellular organization, metabolism, growth and development, reproduction, heredity, and response and adaptation to environment" (Pilet, 128). For something to be described as living, that something must display all of these characteristics. Even though many different people have various opinions about what living means, the following characteristics can be considered general and required characteristics of living organisms. Primarily, all living things are composed of cells. ...read more.

Conclusion

"All living things respond to stimuli in their environment such as heat, cold, sun, darkness, and movement. They also have the ability to maintain homeostasis and state of internal balance" (Pilet, 134). Viruses can not respond to their surroundings like living organisms do, in fact their ability to withstand their surroundings is directly dependent on their host's ability to function. The last characteristic that is generally required of living organisms is that they are not only able to respond but also evolve and adapt to their surroundings. This is something which viruses succeed at. For instance, the influenza virus adapts rapidly all the time; which is why many individuals can receive the "Flu" every year. Using these characteristics, one can categorize things as living or non-living. Because viruses don't meet all of these requirements, it can be concluded that they are non-living. It is evident that outside of living cells, viruses cannot grow or reproduce. Ultimately, viruses can be regarded as an exceptionally complex aggregation of nonliving chemicals, unable to perform many of the same tasks that living cells accomplish every second. ...read more.

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