How can we tell if an organism is alive or not? Is a virus , prion, virod, or a rock a living organism? What is life? Biologist have studied what makes organism alive for many years and have come to the conclusion the there are nine characteristics of life. Each characteristic has a property which applies to how and organism is alive. Life characteristics are as follows: order, metabolism, motility, responsiveness, reproduction, development, heredity, evolution, and adaptation. All of the characteristics of life together are what makes an organism alive. Order is defined as “a precise arrangement of structural units and activities; also, in taxonomy, a taxonomic group comprising members of similar families” (Postlethwait & Hopson, 2011). Order is the most important characteristic of living thing, without order all living organism will die. Organisms are independent individuals that have a level of involvedness and grouping not found in lifeless things. For example, a human is an independent individual (organism) possessing order. The human body is made up of numerous cells. These cells are organized into tissues that make organs, the organs in turn work together to make an organ system within the human body. All living organisms show evidence of a rapid turnover of chemical materials. Metabolism is “a series of chemical reactions by which cells acquire and use energy and that contribute to repair, growth, and other survival processes” (Postlethwait & Hopson, 2011). Living organism’s ability to maintain order is done through metabolism. Metabolism involves the exchanging of chemicals with the outside environmental energy which creates a wide-ranging conversion of the cells. The conversions include repair, maintenance and growth. Nonliving things do not display metabolism, they cannot repair, maintain or growth themselves. Motility is “the self-propelled movement of an individual or its parts” (Postlethwait & Hopson, 2011). Motile organisms have the...
Cited: (n.d.). Retrieved 10 30, 2012, from CCBC Faculty Web: http://faculty.ccbcmd.edu/courses/bio141/lecguide/unit3/viruses/prion.html
Postlethwait, J. H., & Hopson, J. L. (2011). Life. Belmont: Cengage Learning.
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