• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Determine whether or not viruses are actually living organisms.

Extracts from this document...

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.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Energy, Respiration & the Environment section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Energy, Respiration & the Environment essays

  1. Marked by a teacher

    Effect of nitrate concentration on the growth of Duckweeds

    5 star(s)

    The same tap water used increased the reliability of the results as tap water from different taps contain different amount of nutrients. However to the low t- test value obtained in trend A means that there may be factors that affect the reliability of the results.

  2. the effect of bile concentration on the activity of the enzyme lipase during the ...

    milk has gone bad as it will turn very creamy and go rancid. This just means that we will have to repeat the experiment which will cause us inconvenience but has a very low possibility of altering our results Heat the milk in a thermostatically controlled water bath as the

  1. Why the Body Needs Energy? Every living cell within the ...

    * The diaphragm also helps with expulsive body actions e.g > Micturition (urine excretion) > Defecation (faeces expulsion) > Parturition (giving birth) Reference: http://www.gcsesciencedoubleaward.co.uk/c3.htm http://www.bbc.co.uk/schools/gcsebitesize/biology/humansasorganisms/2breathingrev2.shtml Website viewed on 24 / 5 08 Alveoli The exchange of gases in the lungs takes place in the tiny sacs called the alveoli at the end of the terminal bronchioles.

  2. out how different concentrations of the enzyme pectinase affect the degradation of the substrate ...

    I will do so because this way my results will be accurate and reliable * Mass of apple pulp used should be the same for all different concentrations of pectinase (30g). This is because if the mass of apple pulp used for the different concentration of pectinase varies, this means

  1. Weed study. Dandelions - descrption and characteristics. Investigation to dandelion distribution.

    There are many risks and safety precautions in which I took. I had to make sure that I dress up appropriately according to the weather. It was not raining heavily, however it was very cold. Therefore, making sure that I dressed up warm is vital, as there is huge risk of catching hypothermia.

  2. Investigating the effects of different lead chloride concentrations on the growth of cress seedlings

    The preliminary experiment will allow ideas to be tested out and to see if those ideas should be used in the real experiment. This is all done to receive accurate and reliable results in the real experiment. For the preliminary experiments, care should be taken throughout.

  1. the role of pathology service

    to the top, with a ''Buffy coat'' (which contains leucocytes and platelets) in the middle. The appearance of the centrifuged sample can also provide subjective information about the patient's health. PCV can be used as a screening tool for anaemia and to indicate the degree of fluid loss in dehydration.

  2. Infectious Diseases - Avian Flu

    Then between late November and early December 1997, there had approx. 18 new cases had been reported. Six had died, after this about 1.4 million chickens were destroyed around the Hong Kong region to prevent any further possible spread of the disease.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work