What are the 5 characteristics of life?

  1. :blushing: I know this is easy, forgot my biology book though.
     
  2. jcsd
  3. o_O The teacher said 5, oh well.
     
  4. lol, in my class last year, we only had four characteristics of life:

    use energy
    complex structure
    genetic code
    ability to reproduce
     
  5. There are five to be sure:

    1. energy
    2. structure
    3. genetic code
    4. ability to reproduce
    5. stupidity
     
  6. Pengwuino

    Pengwuino 7,118
    Gold Member

    Thats exclusive to adolescent humans :rolleyes:
     
  7. i thought that was funny. :biggrin:
     
  8. Danger

    Danger 9,879
    Gold Member

    And Republicans.
     
  9. Pengwuino

    Pengwuino 7,118
    Gold Member

    At least we're above the single celled organisms called liberals :rolleyes:
     
  10. Danger

    Danger 9,879
    Gold Member

    I wondered how long that would take to get your attention. (What?! No Russ?!)
    The only disagreement that I have with the posted answers is in relation to having a genetic code. That is a characteristic of all known Earth life. Although something is required to carry on the traits of the species, it does not necessarily have to involve genes.
     
  11. Can you give an example where a living thing was able to pass on its traits without having a genetic code involved in the process? I am not being picky, just curious.
     
  12. Danger

    Danger 9,879
    Gold Member

    No I can't, because all known life is Earth-based. Where I should have clarified my meaning involves what the definition of a 'gene' is. Since my definition of 'life' is not restricted to carbon-based, I cannot consider that the medium of characteristics-transferral is restricted to the chemicals involved in Earthly DNA. If a machine intelligence ever evolves, for instance, the traits would be passed on through programming code and construction designs.
     
  13. It's good to note that since the definition of life is so widely argued, it's best to just go with what your textbook says. I remember getting into a huge arguement with my freshman biology teacher about it that lead to her disliking me for the rest of the year. It's just a lot easier to give the book's definition because most high school teachers get offended when you argue a good point.
     
  14. Could be so, but it's probably just included because at this point having genes is a common link between all living things. The moment we have proof of a living thing not using genes as a way to transfer information, the scientific community will be forced to modify it's definition (or dub the old defintion "classical" and continue to teach it while treating the "new" form of life as a separate entity, power to laziness :wink:.
     
  15. Danger

    Danger 9,879
    Gold Member

    I have to agree with Fluxcap if you were asking in relation to a school course. Unless you have a progressive teacher, stick to the book in public. In private, investigate all that you can with an open mind. Although extraterrestrial life is not likely to be encountered within our lifetimes, I'm willing to bet that it won't be based upon DNA when it turns up. That would just be too much of a coincidence.
     
  16. Thanks for validating my suspicion that there are people that are capable of rational thought, but just keep quiet about it to avoid trouble. :D
     
  17. Danger

    Danger 9,879
    Gold Member

    I have more experience with stupid teachers than I would wish upon my worst enemy. That's one of the primary reasons that I never finished high-school. One of the best things that I see about PF is that someone with a different, yet practical, way of looking at things can interact with others about it to maintain his sanity, while still pretending to be subservient to the school boards or CEO's.
     
  18. Well, you are free to think of any possibility you want, but ultimately for it to become science you have to provide evidence that supports your claim. People would still think Einstein was a nut for his "crazy" ideas had he not provided a way for people to test and verify his theories at a later point (when technology finally caught up to him).
     
  19. Danger

    Danger 9,879
    Gold Member

    That's a valid point, but not quite what I was referring to. As a for instance, in grade 12 chemistry a test asked for 3 uses of hydrogen. One of my answers was 'rocket fuel', which was marked wrong because it wasn't in the text book.
     
  20. And I've lost millions of points in math classes when a teacher didn't like the way I solved a problem. Just yesterday in Mulitvariable Calculus my moronic teacher said I did a problem wrong because I didn't use what the book said exactly, even though I still got a correct answer with proper work. It's only the thought of how much effort I've put in so far that prevents me from dropping out.
     
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