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    • #10913
      caliali612
      Participant

      Why do prokaryotes not have any organelles?

    • #89167
      MrMistery
      Participant

      cause they don’t need them

    • #89181
      Stefan
      Participant

      Well If u look at how the organisms evolved – u see that a first ‘cell'(wasn’t really a cell – couldn’t divide) was called liposome – this liposom had a bilayer membrane and was filled with water full of proteins – later came DNA or RNK molecules(which was first to appear isn’t really of my concern, I’m just a cytologist). So lyposomes started fusing – and had their genetic materials combined – etc etc. – And we got a first cell – prokyariotic cell – all the basic functions – and not a large energy consummation needed – usually a small cell – and when in evolution the cell of prokaryots got bigger – tahat was a problem – evolution is going in the way of surface area>>Volume – so to get their P up cell walls started to fold – creating endomembranes and thus the organells( endoplasmatic reticulum being the first) – somewhere along the way mitochondrias appeared(through endosimbiosis)! 😀
      Well this isn’t a direct answer to your question – but I told it in there:
      – Energy consumption
      – Cell size – proportions – surface area>>Volume
      Well u just have to look at prokaryots as a more simply organized cell…

    • #89354
      GaryGaulin
      Participant

      Wikipedia has a list of prokaryote organelles:

      carboxysome – carbon fixation
      chlorosome – photosynthesis
      flagellum – movement in external medium
      magnetosome – magnetic orientation
      nucleoid – DNA maintenance
      plasmid – DNA exchange
      ribosome – translation of RNA into proteins
      thylakoid – photosynthesis

      http://en.wikipedia.org/wiki/Organelle

      Contrary to common belief some prokaryotes are also reported to have membrane-bound organelles.

    • #89363
      JorgeLobo
      Participant

      I’d not look to wikipedia for scientific reference. They’ve no organelles because that is the definition. One can always find (or imagine) divergence from almost any such definition.

      There is no "why" as that presumes there’s a rationale. They just don’t.

    • #89376
      GaryGaulin
      Participant

      Hi Jorge,

      Sometimes Wikipedia is the best resource available. The exact same list and description is found at other sources but it’s hard to say whether they are quoting Wiki or Wiki is quoting them. There are other sources of information like this:

      http://library.thinkquest.org/C004535/p … cells.html

      What is now taught in (at least) US schools and even in teaching college is now obsolete. All textbooks I have seen or were described to me are wrong about this and the modern origin of life theories. I estimate they are on average 10 years behind reality.

      Here is my origins presentation:

      http://originofintelligentlife.blogspot.com/

      That is the direction science is now going. And it was the result of over 20 years of following trends and studying things educators are not taught. So I do not pick a resource like Wikipedia and blindly believe it, I used it because it is in fact the most modern information available.

    • #89379
      JorgeLobo
      Participant

      wikipedia may be an excellent source for nonscientists. To biologists, it’s as trivial as the other internet sites you offer.

    • #89380
      GaryGaulin
      Participant

      I understand that Wikipedia is written for the general public but that does not change the fact that at least on the internet a new scientific view is now replacing the old.

      If you want to see scientists discussing the problem then here is one I found interesting:
      http://scienceblogs.com/transcript/2007 … nelles.php

      Do you have a recent reliable source of information to the contrary? Without that, there is nothing I can do but assume that you were not aware of this having happened and are another attacking the messenger.

    • #89384
      JorgeLobo
      Participant

      Science isn’t done on the internet.

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