To say something is alive, conscious, and or intelligent has a unique meaning for each person. We can try and define these aspects, but we have no proof; all we have are supporting facts. The correct definition of ÃÂlifeÃÂ still cannot be agreed upon by scientists; there are simply too many exceptions. Scientists have, however, come up with nine main characteristics of life, although this still does not have unanimous support. Arguments include the characteristic of reproducing being part of the nine, for animals such as mules are thought to be alive and yet canÃÂt produce offspring. Nonetheless, the other characteristics of living things, including growth, adaptation, responsiveness, organization, the usage of energy, being made of cells, having a definite form and limited size, and death seem to be necessary conditions for life.
One major argument in this field is whether prions are alive. As Sean Henahan said in his article New Findings on Prions, ÃÂÃÂRogueÃÂ prions, which are misfolded forms of the normal prions, are unusual in that they can convert normal prions into copies of themselves.ÃÂ
College of Medicine & JNM Hospital
Electron micrograph of Bacteriophages
From left to right, the structures of A-, B- and Z...They do not metabolize, they simply collide with correctly folded proteins. Because prions are not actually alive, and donÃÂt have any genetic information, they canÃÂt be killed by any of the common ways such as heating, sterilizing, and more. Prions are not made of cells, canÃÂt reproduce on their own, do not grow or undergo division, and do not transform energy. Many people believe that they are not alive, that theyÃÂre just one of our own proteins that has gone wrong and that has the capability to cause normal PrP to go wrong, too.
Similarly, viruses are a controversial issue. They are somewhere between complicated complexes and extremely simple biological entities. Viruses have some of the structures and show some of...