What are Living Things?
You may well be sitting there thinking “well nah, that’s obvious”. To a certain degree it is but what if I were to tell you that top scientists at NASA are still working on a proper definition and many top biologists are divided over whether a virus is a living thing? The best we’ve got so far is MRS GREN.[i] MRS GREN is an acronym that states that in order to be considered living it has to do all these processes: · Movement · Respiration · Sensitivity – notices changes in it’s environment · Growth · Reproduction (a virus can’t reproduce on its own it needs a host[ii]) · Excretion · Nutrition – eats The term we use to describe a living thing is organism – not to be confused with a very similar word with a very different meaning. We divide organisms into three groups: plants, animals and micro-organisms[iii]. Each has separate characteristics that allow us to separate out each. [i] Even better than poking it with a stick- though not as fun. [ii] When you have a cold don’t tell your partner: “sorry honey but I’ve been having sex with [pause for gasps and/or slaps] a virus and there are 3 million children.” [iii] Though many micro-organisms are split into plants and animals since they have features the same as plants or animals, but you don’t worry about that yet.  |
