PROPERTIES OF LIFE 3
Tobe classified as a living thing, an organism should fulfill the nineproperties of life. These properties include:
Order:Thisis the arrangement of structures in relation to one another.Structures in living things are arranged in the most orderly mannercompared to the nonliving things. This orderliness allows them tofunction and sustains life. Disordering the structures can lead toloss of life or deformity.
Metabolism:Livingthings require energy for survival, growth, repair of tissues andproduction of new cells. They do this by obtaining energy from theenvironment, breaking it down through chemical processes, and usingit for the purposes outlined above. Metabolism also helps to maintainorder by reorganizing disorganized structures.
Motility:Anorganism uses its power to move (Postlethwait& Hpson, 2011).Animals display the most developed motility by literally moving fromone place to another on their limbs in search of food, evadingdanger, leisure, exercise, etc. Plants also exhibit subtle movementthrough growth, shifting together with sunlight, opening and closingof flowers, etc.
Responsiveness:Livingthings detect changes in their environment and respond to them. Theresponse can be instantaneous, like letting go of a hot object or theinstant folding of the venous fly trap when touched or gradual suchas the shifting of a houseplant’s leaves towards the light or theshedding of leaves during the dry season. All types of tropism(photo, thigmo, hydro, geo etc.) are examples of responsiveness inliving things.
Reproduction:All living things give rise to offsprings of the same kind, whethersexually (offspring of the same kind but not identical to parent) orasexually (identical to parent). This is the property that ensurescontinuity of life.
Development:Intheir young stages, living things are usually small and simple.However, with time, they grow and increase in complexity as theyreach maturity. This change in complexity is referred to asdevelopment.
Heredity:Livingthings transfer their genetic traits to their offsprings, who alsotransfer them to their offsprings in turn. This transfer of traits iscalled heredity and is the reason why offsprings are of the same kindas the parents. Identical twin is a typical illustration of heredity.The asexual reproduction of a microbe is another illustration of howtraits are passed from parent to offspring.
Evolution:Organismsundergo changes over time so as to fit and survive in a particularenvironment.Evolutioncould entail modifications in the genetic structures or organs so asto survive. By tracing the family trees, we realize that oldermembers of the family are a bit dissimilar with the current members.The differences between Ramapithecus and the present day human beingare more pronounced than those between Homosapiensand Homosapiens sapiens.
Adaptation:Thisproperty is closely related to evolution. Organisms possess specificstructures that make them suited to the environment and maintainrelationships with other organisms in the ecosystem (Alberts et al.,2013). If an organism does not have these structures orcharacteristics, they change and develop the traits else they dieand become extinct. As Charles Darwin put it, only the fittestsurvive. Hence, living things have to adapt to the environment so asto survive.
Viruses,prions, and viroids do reproduce and evolve, but they are notconsidered as living things. This is because they depend on the hostcell for their existence. Even though they exhibit traits ofreproduction, they do not reproduce by themselves they coerce theinfected cells to reproduce (Alberts et al., 2013). Concerning theirevolution, it is more or less the same as their reproduction style.They change rapidly, depending on the cells they invade. Their hosts’altered responses are the reason for their changes hence they do notevolve by themselves. In addition, prions have no DNA or RNA.
Alberts,B., Bray, D., Hopkin, K., Johnson, A., Lewis, J., Raff, M., … &Walter, P. (2013). Essential cell biology. Garland Science.
Black,S. (2013). The Nature of Living Things: An Essay in TheoreticalBiology. Butterworth- Heinemann.
Miller,G. T., & Spoolman, S. (2011). Living in the environment:principles, connections, and solutions. Nelson Education.Chicago
Postlethwait,J.H. & Hopson, J.L. (2011) Life. Student Edition. Brooks/Cole,Cengage Learning.
Starr,C., Taggart, R., Evers, C., & Starr, L. (2015). Biology: Theunity and diversity of life. Nelson Education.