CHROMOSOMES

Viewing 15 reply threads
  • Author
    Posts
    • #7820
      mehdi71000
      Participant

      HI EVERY ONE.
      IS THERE ONLY ONE SET OF CHROMESONE IN ONE CELL?
      THANKS

    • #73815
      canalon
      Participant

      There are no chromesone in any cells. But depending of the kind of cells you can have from one unique chromosome (bacteria) to tens of pairs of chromosome (human have 23 pairs). You can have look here:
      http://en.wikipedia.org/wiki/Chromosome

    • #73816
      mehdi71000
      Participant

      No 😕 You got me totally wrong. Say humans have 23 chromosomes. So let’s say we opened up a human cell nucleus. Would I find only 1 set of 23 chromosomes or 100 sets of the same chromosome?

    • #73818
      Khaiy
      Participant

      I guess I’m a little confused about your question, but a chromosome (as depicted on a karyotype chart) is the individual’s genome condensed to make it ready for replication; chromosomes are just specific parts of the DNA. There are 23 of these distinct parts, and two copies of each. No more, no less (with the exception of genetic disorders). Every bit of DNA is accounted for in those 23 pairs, and you can’t have more than that because there isn’t any more DNA to condense. I hope I answered your question, let me know…

    • #73820
      mehdi71000
      Participant

      Ok I’ll explain more.
      if I open a nucleus would I find only the 23 chromosomes. And no more of the same? or thousands of the same 23 chromosomes. I guess what im asking is how many of the 23 are there in the cell

    • #73821
      LilKim
      Participant

      There are 2 copies of chromosome 1
      (One is maternally derived, the other is paternally derived)

      There are 2 copies of chromosome 2
      (One is maternally derived, the other is paternally derived)

      There are 2 copies of chromosome 3
      (One is maternally derived, the other is paternally derived)

      There are 2 copies of chromosome 4
      (One is maternally derived, the other is paternally derived)

      and so on and so forth… all the way to X and Y.

      Creating a grand total of 46 chromsomes (2 copes of each chromosome…. where either copy is inherited from your mother or father)

    • #73823
      mehdi71000
      Participant

      Ooh I see thanks fro clearing that up for me. So what would happen if I inject more of the chromosome into the cells nucleus? Would the genes express more? Resulting in more growth and size or maybe change structure? By the way I’m not talking about human’s chromosomes, chromosomes in general.

    • #73826
      david23
      Participant

      a single chromosome carries an enormous amount of genes, an organism will not be well if you add something like that to it. Plasmids are simple and most of the times depending what transcription factors needed, you can get a high expression.

    • #73831
      mehdi71000
      Participant

      Thanks guys really appreciated. Great stuff.

    • #73849
      LilKim
      Participant

      Evolution has selected for the number of chromosomes that a "normal, Healthy" person (organism) has. So gain of chromosomes or loss of chromosomes are detrimental …. (because each chromosome has MANY MANY genes)

    • #73857
      mehdi71000
      Participant

      Thanks Lilkim.
      I still have many serious doubts about evolution. Maybe its true. but my doubts is based on why all the animals look perfect if they are mutating why we don’t have like a 2 headed bird of some weird spices that is like human but look a bit different like 6 fingers or toes I’m sure people with 6 or 3 fingers can all so survive as good as 5 fingers. I’m also very concerned about the way evolution is used in today’s society. my friend told me once the reason he doesn’t believe in god is we have all evolved from bacteria and the bacteria it self was created from chance of molecules sticking together to form a bacteria and by chance some how they form to recognize light and so on. I how ever told him if you wake up one day in a new planet and see a huge skyscraper or a or a suit jacket would you suggest it has been made by chance or have doubts of a creator for that sky scraper. Even in the evolution book it’s about the origin of spices not the origin of life. My teacher told me once of a law in thermo dynamics (I think). He said if you get a jar of 3 colour beans and lay them separately and neatly on top of each other if you shake them for million years you will never get the same combination same as ink in water. No matter how many times you shake it you will not end up with the drop that is seporated from water. I think perfection surrounds life. If you buy a lotto ticket to win you need to play many times to get the 6 numbers. And there are trillions and trillions of molecules in human body. So I say for a human to evolve there must be countless numbers of imperfect humans much much more than perfect humans. Even in today’s time if we are still evolving. There must me billions and billions of imperfect proteins and enzymes and unfinished genes and I don’t see a device in human body that alters dna so I cant believe my eyes area formed by chance. Sorry I needed to get that of my chest.

      Sorry if I have a caused headache but I say life is to be expressed freely. I still like the idea of evolution. I say to evolve is to be alive

    • #73866
      LilKim
      Participant

      Yeah, i’m don’t exactly wan to get into a evolution conversation … But scientifically, there is more evidence that evolution is ‘real’.. than any other ‘theory’.

      So, lets look at it in very general terms… The reasoning behind why I say 46 chromosomesis "evolutionarily selected" is simple. Becaurse if you have 45 chromosomes (or less) you’re either pretty sick or dead … if you have 47 chromosomes( or more) you’re either pretty sick or dead. Thus, there is a reason why we must have 46 chromosomes … because it is a "selected" number of chromosomes necessary for viabiliy (in humans).

      Remember Darwin’s "Survival of the fittest" theory (as a basis for evoulation)? Chromosome number is an EXACT example that lends suppor to his theory. (Because you are most ‘fit’ if you have 46 chromosomes).

      There was something that I was thinking about the other day (although i’m not sure if it’s an example of evolution). I heard a news report that stated that more people are wearing glasses nowadays than 50 years ago, and by year (???) it is projected that close to 100% of the human population will need corrective lenses by adulthood.

      As non-glasses wearing individual, I was pretty shocked when heard that statement. And then I started thinking about the american indians, that roamed the earth HUNDREDS of years ago. They survived on the land by farming, fishing, and hunting. And as I thought more about this whole vision thing going downhill (as an evolutionary process), I think it’s not completely unreasonable to think that the American Indians probably had very-good vision… because being able to see well was essential for survival (ie hunting with spears, bow and arrows) back then …

      However, in modern times, I hunt by going to the grocery store and ordering a steak, and picking up a bag of pre-made salad mix. My hunting requires no physical activity and because my steak isn’t running-away and hiding .. hunting for it doesn’t require perfect vision because I can get close enough to the sign to read the words "S-T-E-A-K".

      So you ask why I think this is an example of evolution? Well, nowadays, we don’t need our eyes to be ‘that-good’, because we can just go down to the 1-hr eyeglass shop and have perfect vision. However, eyeglass shops didn’t exist hundreds of years and people from those times relied on their senses (ie vision) to be able to hunt, find safety and to survive. (Could you imagine if a entire tribe of indians had poor vision? They probably wouldn’t last very long because they couldn’t see their food.)

      But, with the advent of cheap eye glasses we can STILL survive even if we have poor vision. (Therefore, people who were not "fit" before… are now "fit" for survival because of eyeglasses!!!!)

      … so, yah, i’m not sure if this is an example of evolution? (This is just something that I was thinking about while driving one day)

      A more factual example of evoultion is the story of sickle cell anemia (SCA).. SCA is essentially a point mutation in the B-globin chain of hemaglobin that has been evolutionarily selected for. People who are heterozygous at the ‘SCA’ (having a normal SCA copy on one chromosome, and having a mutated SCA copy on the other chromosome) tend to not get fatally sick, and are resistant to malaria. So, if you lived in an area where malaria infection rates were particularly elevated … being heterozygous for this mutation would give you a survival advantage over:

      1.) People having 2 ‘normal copies of SCA (Because they are suceptible to malaria infection)

      or

      2.) People having two mutated copies of SCA = Sickle Cell dises (they’re generally REALLY sick, and have acute crises that often result in death)

      Thus, having 1 copy of the abnormal SCA is "selected" in areas of the world where malaria is prevalent (ie. certain regions in africa) because these types of individuals are "fit" and evoultionarily selected for… because of malaria

      (Read more here: http://en.wikipedia.org/wiki/Sickle-cel … se#History)

      …. so, tell me what you think? I think that these may/may-not be examples of evolution

      (and i’m not talking about the kind of evolution that says that humans came from bacteria … cuz I have NO opinion on that… at all)

    • #73869
      LilKim
      Participant

      So I realized that I didn’t address your particular points:

      "we don’t have like a 2 headed bird of some weird spices that is like human but look a bit different like 6 fingers or toes I’m sure people with 6 or 3 fingers can all so survive as good as 5 fingers."

      A bird having 2 heads would probably have an aerodynamics problem… and would easily become prey to a predator (and become extinct). However I remember reading about a two headed species of reptile (?? as a child) that would use it’s heads to confuse it’s prey.

      As far as fingers and toes… There are plenty of people around who are born with +/- 10 fingers and toes. It’s actually much more common than you think (parents can often opt to have an extra toes or fingers removed shorty after a child is born that way … ) Also, there are plenty of people who have 2 fingers "ectrodactyly" (http://en.wikipedia.org/wiki/Ectrodactyly) … and they are just fine. So finger number? Yeah, I don’t know why most people have 10 fingers and toes .

      "So I say for a human to evolve there must be countless numbers of imperfect humans much much more than perfect humans. Even in today’s time if we are still evolving. There must me billions and billions of imperfect proteins and enzymes and unfinished genes and I don’t see a device in human body that alters dna so I cant believe my eyes area formed by chance"

      In fact there ARE countless numbers of "imperfect" humans … The reason why we don’t see them walking around is because they die prematurely (before birth or shortly thereafter). I used to work in a clinical cytogenetic laboratory where people would send their dead-fetus, hoping for some insignt into WHY it died. And, more than 50% of the time, there was a severe genetic abnormality (ie. imperfection) .. which resulted in morphologically abnormal-looking babies that died due to their "genetic problems"…

      So why don’t we see these strange-looking ‘people’? Normally, women will often "lose" these types of pregnancies due to fetal death (ie. due to loss or gain of genes, or mutated/non-functional metabolic protiens).. or some unknown mechanism by which the mothers ‘body’ selectively eliminates a fetus that isn’t perfect. (which has been observed due mothers more-frequently "losing" the genetically-abnormal fetus while pregnant with fraternal twins.)

      So, just because you don’t see alot of abnormal people walking around doesn’t mean that mutations that give rise to evolution doesn’t exist. It just meant that most mutations result in an un-fit human.. that die very early-on (and that’s why you REALLY don’t see people with 2 heads).

      BUt the bottom line is that i’m not trying to force my opinions on anyone … I just believe in being openminded, enought to make conclusions based on what YOU know (and not what others tell you)

    • #73874
      mehdi71000
      Participant

      well I think the person from age of 18 + is capable of making babies but loss of eye sight starts at over 30+ I say TV is the problem because if your eye stops to focus on close and near things that’s when the lens muscles become lazy and the person is end up with bad eye sight. You can blame the small house TV type of work you do and magazines. If I was Native American I would need to look at distance trees and land so my eye is more active to focus to near objects like my food or far like my cows or bear etc…
      My teacher told me when you’re at your computer look at distance objects so your eye doesn’t become weak.
      Another thing is we are designed to die. Even bacteria. You might say because our ancestors never lived to be 30+ so body can’t cope but whales die so as great white shark and element etc
      How ever if what you’re saying is true maybe that’s why they said there is a lockless monster. But I think they die too

      Evolving does exist. Like bacteria become resistant to some medication. But how is done is a mystery to me.
      and if 50% of humans die out of genetic imperfections i say some humans are designed to evolve and some rant. Because if they were to evolve they would have that (for example)6 fingers and toes. And one question why humans have hair or eyebrows and mustash and beard? They do get in the way
      i say there is a designer. The imperfections are only errors in the software.
      if you have more population you see more imperfections. We are designed to see the difference. if you see a room full of black butter flies. And 2 white butter flies you will focus on the white ones same as room full of white butter flies and few black ones. There are 4 babies born every second I doubt 2 have genetic problems.
      Maybe evolution is act of god? Like we are still under construction and in religions they say we are being tested. Maybe this is the case. We are in a test for more advanced species. Or aliens are responsible who knows? In this big universe we cant be the only ones? Maybe we are like lab mice to them since they are well advanced. 😯
      I don’t mind evolving not at all but some times its used in most silliest situation. I not implying on chromosome theory by Lilkim not at all. Evolution could be who knows. I don’t play too much lottery anyways

    • #74347
      lg1
      Participant

      Like many superficially reasonable just-so stories about the effects of evolution on human beings (viz. eugenics), the idea that eyeglasses are degrading the human gene pool is not valid. I don’t know what news media have claimed about corrective lenses and genetics, but this is from a peer-reviewed journal:

      “Corrective lenses were invented far too recently to have allowed a substantial increase in genes that cause myopia. This argument is supported by the dramatic myopia increase in native groups newly subjected to formal education in childhood (Young et al., 1969).” From “The Dawn of Darwinian Medicine,” George C. Williams; Randolph M. Nesse, The Quarterly Review of Biology, Vol. 66, No. 1. (Mar., 1991), pp. 1-22.

      Myopia is strongly heritable, but only develops when the eyes are used for much close work (e.g., reading) in childhood. The global increase in spectacles-wearing is not a result of eyeglasses frustrating natural selection and so degrading the human gene pool, but of cultural practices activating a preexisting genetic potential.

      Astonishingly, the above-cited paper was cited in 1998 (in “The future of genetic epidemiology,” by Schork, Cardon, and Xu, Trends in Genetics, 1998 V. 14 N. 7.) as sole support for the claim that “Poor vision would normally put one at a tremendous selective disadvantage, but the modern contrivance of corrective lenses has facilitated the maintenance of relevant myopia genes, and have led to a general weakening of visual capacities.” So strong is the bias, apparently, toward a crude adaptationism, that Schork et al. read Williams and Nesse as saying the exact opposite of what they really said. That way lies eugenics.

      Another reminder, by the way, to trace one’s references back to primary sources whenever possible.

      Sincerely,

      Larry

    • #74360
      kotoreru
      Participant

      Sorry, I just came across this topic – has anyone mentioned polyploidy anywhere?

      (the original topic, that is, not this Evolution debate)

Viewing 15 reply threads
  • You must be logged in to reply to this topic.