Exception to Characteristics of Life.

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    • #301
      trus
      Participant

      Greetings,

      I have a bio quiz question that I cant seem to find the answer to and was wondering if any of you gifted individuals could help me out.

      The question is:

      What has all of the characteristics of life (ie, grows, reproduces, is made of cells) except does not have the last characteristic, which is “has DNA or RNA”?

      ~Paul

    • #19055
      biostudent84
      Participant

      Viruses =D

    • #19056
      ERS
      Participant

      do viruses really ‘grow’ though….

    • #19057
      biostudent84
      Participant

      That’s true…knee-jerk reaction. Viruses have been up for debate for a long time.

      Hmm….what else?

    • #19065
      trus
      Participant

      Virus was my first guess too, but they contain RNA. So it must be something else. (This is a tough one!)

    • #19080
      2810712
      Participant
      quote trus:

      Greetings,

      I have a bio quiz question that I cant seem to find the answer to and was wondering if any of you gifted individuals could help me out.

      The question is:

      What has all of the characteristics of life (ie, grows, reproduces, is made of cells) except does not have the last characteristic, which is “has DNA or RNA”?

      ~Paul

      I think, we should first decide that in what sense should we take the words cell, grow, reproduce. It can be any thing – nonliving also.But , if it,s a question in bioquiz then can it be a non living thing?
      hsg

    • #19081
      mith
      Participant

      red blood cells?

    • #19086
      Poison
      Participant

      I’m not sure but can it be PRION? I do not have so much knowledge about it but i know that it has neither DNA nor RNA. It is made of only protein.

    • #19102
      bioguy
      Participant

      a funguss?

    • #19112
      ERS
      Participant

      prions do not grow, but they do carry a small bit of genetic material.

    • #19121
      mith
      Participant

      Anyone seen the virus in the movie Andromeda Strain?

    • #19179
      thank.darwin
      Participant
      quote mithrilhack:

      Anyone seen the virus in the movie Andromeda Strain?

      No I haven’t – is it a good movie?

    • #19203
      mith
      Participant

      It’s this crystal space virus that feeds on energy and matter. It grows and grows and is seemingly unstoppable. Well, I won’t ruin the story 🙂

    • #19221
      thank.darwin
      Participant
      quote trus:

      Greetings,

      I have a bio quiz question that I cant seem to find the answer to and was wondering if any of you gifted individuals could help me out.

      The question is:

      What has all of the characteristics of life (ie, grows, reproduces, is made of cells) except does not have the last characteristic, which is “has DNA or RNA”?

      ~Paul

      A virus – Still up in the air

    • #19283
      waupor
      Participant

      I have far less bio knowledge.
      I think virus is not living thing.

      I do also think red blood cell is no DNA.
      It has no nucleus for increasing the ratio of surface area to volume.
      But I don’t know whether the DNA present in the cytoplasm or not.

    • #19291
      thank.darwin
      Participant
      quote waupor:

      I think virus is not living thing.

      It has many of the things that make something living – It needs a host to survive – even though small pox can survive for years in the environment without a host (if I’m wrong please correct me; I would like to know)

    • #19294
      Poison
      Participant

      someone correct me if im wrong but viruses seem like a form between living and nonliving. arent they? they need host to survive, they have sensivity to heat and they are not immortal means that they carry characteristics of life. But they turn to cristal form without a host. (not forever but for some time of course) which seems like a characteristic of nonliving.
      So, are they living or nonliving or what else ❓

    • #19298
      ERS
      Participant

      Poison,
      THAT is a good question, and one that science continues to debate. At what point can you start making exceptions to the characteristics of living vs. non-living materials? If you make an exception for viruses will we also have to excuse prions…

      Anyone else?
      ERS

    • #19302
      mith
      Participant

      Note the original question states it’s made of cells. The last time I looked the virus isn’t a self-contained self maintaining entity….there’s really no maintanence.

    • #19319
      Poison
      Participant

      In one of the books I’ve read, it says:” The things which can do respiration are considered to be LIVING. the others are considered to be NON-LIVING.”
      Do you think that respiration is exactly the point which living and non-living things can be classified? It sounds a bit strange to me. 🙄
      what do you think?

    • #19328
      trus
      Participant

      Hello everyone. Glad to see that this question has sparked some conversation. While I still havent discovered the answer to this riddle, let me help those of you that are wondering whether a virus is alive for dead. The 6th qualification that needs to be met for the object to be considered alive is “to contain DNA or RNA”. Viruses contain RNA.

      ~trus

    • #19331
      waupor
      Participant
      quote Poison:

      In one of the books I’ve read, it says:” The things which can do respiration are considered to be LIVING. the others are considered to be NON-LIVING.”

      Then how about PC’s CPU ? Do you think that they can thinking themself ? Are they a living things ?

    • #19334
      Poison
      Participant
      quote waupor:

      Then how about PC’s CPU ? Do you think that they can thinking themself ? Are they a living things ?

      I couldnt get the question. Viruses are made or organic material arent they? what is the relationship between PC and virus?

    • #19339
      mith
      Participant

      Well you could argue that pc’s (robots) are living. They consume electricity and metals. They have intelligence(somewhat). They reproduce by assembling clones of themselves and in other cases making better copies and improving upon existing designs.

    • #19343
      Poison
      Participant

      Are robots made of organic material? Or do they carry DNA or RNA? No. But viruses do. Dont they?

    • #19344
      biostudent84
      Participant

      Viruses carry RNA, true.

      But viruses are not made of cells, a stipulation clearly stated in the modern accepted definition of life.

      If you want to call viruses life, then you must first confront the entire biological community to petition for the definition of life to be changed. Or at least redefined.

    • #19351
      Poison
      Participant
      quote biostudent84:

      If you want to call viruses life, then you must first confront the entire biological community to petition for the definition of life to be changed. Or at least redefined.

      I’m not trying to call viruses life. I just want someone to persuade me.

    • #19352
      canalon
      Participant

      Hello,

      Virus can carry both RNA or DNA, but it cannot self replicate, it needs a cell replication mechanism to copy and multiply its genetic materia and to synthesize its enveloppe. They are basically genetic material wrapped in a membrane, without any machinery.
      Prions do not carry genetic materials, they are proteins that change the folding of normal proteins (produced and coded by a cell) into the pathogenic form in self catalytic process.

      Are they alive ❓ The limit is hard to draw.

      If it was not for the “made of cells” conditions, crystals could have been a good answer, they grows using only free material in the environment, without the need of a complex external machinery (i.e. a cell). And they are indeed making new copies of themselves. They were even supposed to have been one of the possible origin of life, though it is note the most highly favoured. And they are definetly non liveng entities.

      HTH

      Patrick

    • #19363
      Moff231Dawrin
      Participant

      you know, trus, you might want to ask your biology teacher that one. It would be interesting to see what he/she thinks. Also, did you get that quiz back yet?
      That’s a good question, and as far as I can tell, a Virus is as close as it comes. the next thing I’d guess is prokaryotic cells, but those have DNA. I’m curious to find out, so if you get any idea as to what it might be, please tell us.

    • #19366
      Poison
      Participant

      Thank you all for your explanations. Now they really seem to me like non-living.
      But I have one more question. (I think I asked it before). Can ‘respiration’ be the point where living and non-living differ? (I mean the exact point)

    • #19369
      biostudent84
      Participant

      While it is not included in the actual definition of life, I would have yo say yes, you might be right on that one. It would be hard to judge unless we can find a packet of chemicals that undergoes respiration but fails to meet the parameters of life…or one that does meet said parameters, but fail to respire.

    • #19381
      Moff231Dawrin
      Participant

      that’s a little but of an paradox, isn’t it? after all, don’t living living things need to be able to go under respiration for energy? so how can something live and not undergo respiration? It’s like what they say, “When you breathe, you respire. When you don’t breathe, you expire.”

    • #19386
      Maxwell
      Participant

      Viruses are not considered to be alive for two reasons:

      1) They do not produce their own energy
      2) They cannot reproduce on their own. They need the help of a host cell’s machinery to produce more viruses.

      Viruses also cannot be the answer to the riddle because, as stated by biostudent, they are not made of cells. Additionally, all viruses have some sort of genetic material in the form of either RNA or DNA depending on the virus. The RNA or DNA can be either single or double stranded.

    • #19401
      RobJim
      Participant

      I don’t see any way for this to have an answer and not be a trick question. All cells that grow and reproduce have RNA at least. I’m not sure if there’s any true life without DNA, but if so it will have RNA.

      The answer could be something like a beehive, but the bees have DNA and RNA and are essential for the reproduction and growth…it sounds like a trick question of some kind.

    • #19496
      thank.darwin
      Participant

      Right… can any living thing replicate without RNA or DNA?

    • #19498
      biostudent84
      Participant
      quote thank.darwin:

      Right… can any living thing replicate without RNA or DNA?

      Actually, yes. DNA sequencers do it all the time.

    • #19512
      thank.darwin
      Participant

      What are DNA sequencers? (I’m only in my first year of biology -we haven’t gone over anything like that)

    • #19581
      RobJim
      Participant

      DNA sequencers are machines that read DNA and then report to scientists what the sequence of bases is in the DNA.

      They do not replicate themselves; nor are they alive. What they do is replicate strands of DNA that are in the machine in order to read it.

      Take a look at this website:

      http://infohost.nmt.edu/~biology/sequencer.htm

    • #19640
      thank.darwin
      Participant

      Thank-you RobJim, that helped a lot!

    • #19700
      Moff231Dawrin
      Participant

      DNA sequencers sound like they’re a special type of protein. if so, then wouldn’t they have at least some DNa or RNA, because I thought proteins were made from ammino acids?

    • #19705
      mith
      Participant

      Read the info at the link and the posting itself. Both will tell you the sequencer is machine.

    • #19708
      Moff231Dawrin
      Participant

      oops. my bad. I was thinking about helicases.

    • #20011
      MrMistery
      Participant

      The viruses have been up for debate for a long time: nobody was able to determin if they are alive or not, so in the present they are called infectious entities. It is also true that viruses can contain DNA or RNA but they do not have their own methabolism nor are they capable of reproduction. But think of it: are viruses more alive than the printer or the computer monitor? Of course they are. Also, they are less alive than a bird or a toad. So, my personal opinion is that if you look at life as angradual state then both viruses and prions(which, from what i know do not contain DNA or RNA) can be alive, but at different levels. This is how i see this problem. I don’t know if anyone understands anything from what I just wrote, I hope yes.

      By the way, someone mentioned red blood cells. You first have to consider that red blood cells have a nucleus at all animals except mamals. But, i consider them as being part of life and not life itself. If a cell is alive than can you consider the mithocondrion inside it alive(maybe it’s not the best example since it is a known fact that mithocondrion are primitive bacteria which have come into symbiothis with the cell a long long time ago- anyway, you see my point)

    • #20055
      Lee
      Participant

      virus i think

    • #20056
      RobJim
      Participant

      I believe that viruses are not considered alive, as they don’t fit the definition of life.

    • #20058
      Poison
      Participant

      yes RobJim thats right. We discussed this so far.

    • #20094
      Dr.Doom
      Participant

      Viruses do have genetic material (ssRNA, ssDNA …etc). Prions are proteins; they do multiple through protein-protein. All other animate objects have genetic material (yes even fungus); therefore, the cloest thing may be a prion, but i don’t know if you can consider that as an animate object.

    • #20103
      thank.darwin
      Participant

      Right Dr.Doom… 😀

    • #20105
      Poison
      Participant
      quote Dr.Doom:

      Viruses do have genetic material (ssRNA, ssDNA …etc). Prions are proteins; they do multiple through protein-protein. All other animate objects have genetic material (yes even fungus); therefore, the cloest thing may be a prion, but i don’t know if you can consider that as an animate object.

      I guess we can’t. 🙂

    • #20167
      Wilmer
      Participant

      Of course virus is alive.
      They reproduce because they are automated to do so, but so are animals (such as humans) and animals are considered alive.

      They have no choice but to invade cells and so on but our will is just as limited as theirs (just that our will can handle more complex situations).

      And for the riddle: Bee hives are made of cells and they grow. And they kind of reproduce (new hives are built).

    • #20170
      biostudent84
      Participant
      quote Wilmer:

      Of course virus is alive.
      They reproduce because they are automated to do so, but so are animals (such as humans) and animals are considered alive.

      They have no choice but to invade cells and so on but our will is just as limited as theirs (just that our will can handle more complex situations).

      There’s more to the definition of life than reproduction =)

      Viruses are not made of cells, they do not arise from cells of the same species as themselves, and they do not enact the process of respiration.

      Whether or not a virus is a living being is still under debate by the biology community. No official verdict has been accepted yet =)

    • #20175
      Wilmer
      Participant

      I think that “has to be made of cells” is a silly concept for life. 😛
      The first living organism probably wasn’t a cell (even thought all cells are it’s children).
      It is not likely that membranes and all the proteins nessecary just popped up from nowhere. The first strain of DNA or RNA or whatever can’t have been complex.

      The first thing to live was the first thing that started to copy itself. Those who started feeding before copying and protecting their DNA (or RNA or whatever) with membranes were less likely to be broken by radiaton.

      This is just what I think. Don’t listen to me if you are writing something for school.

    • #20189
      biologyistehcool
      Participant
      quote Wilmer:

      I think that “has to be made of cells” is a silly concept for life. 😛
      .

      me too lol 😀

    • #20193
      James
      Participant

      Our classifictions of life are dominated from the majority of ‘living’ organisms we have so far observed. If we classed life as being made of cells, or those that do our ‘life processes’ etc, then if we met aliens, perhaps not carbon based, which were not made of cells or did our ‘life processes’, then we wouldn’t class them as alive, even if they were free moving and even intelligent organisms. Our classifictions should not be rigid, I’m sure that if we came across intelligent organisms on a far planet, despite not doing all of our life processes, we would say they were alive. So why don’t we classes viruses as alive?

    • #20215
      Poison
      Participant

      We discussed wheather viruses are alive or not. I think you can hava a look at them.

      about215.html
      about312.html

    • #20222
      MrMistery
      Participant

      The aliens we would meet will deffinetly have their own methabolism. Viruses do not. That is a major point in why they are not considered alive(by the way, I also consider viruses alive, just less alive than other things)

    • #20258
      Wilmer
      Participant

      Atleast ONE of the aliens on another planet would have to eat and grow. All the other aliens could live like viruses.

    • #20262
      biostudent84
      Participant
      quote Wilmer:

      I think that “has to be made of cells” is a silly concept for life. 😛
      The first living organism probably wasn’t a cell (even thought all cells are it’s children).
      It is not likely that membranes and all the proteins nessecary just popped up from nowhere. The first strain of DNA or RNA or whatever can’t have been complex.

      Read the research journals, textbooks and articles published by biologists. Whether or not you think it is “silly” is not a major concern to the Virologists and Taxonomists that are being paid big bucks to determine whether or not viruses are alive. When those researchers senior to us are completely certain whether or not they live, they will let us know.

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