is dna a double helix can you be sure give one solid reason to support your believe?
402047
Yes, you can probably see the structure of DNA with a tunneling electron microscope.  \n\nIt's very unlikely that Watson and Crick deluded us, because their conclusions were subject to peer review by the scientific method, and other scientists would've taken delight in disproving their theory.
135772
molecules are a way of science. My theory is that Scientology is and the bible are both correct and incorrect. I mean if we evolved from single-cells organism that means im related to a cockroach, potato bug,arachnids,etc. And if the world has only been around for 1 million years then how could 65 million year old fossils be found? So molecules are just science its self. but don't fully go by me its just a theory
202746
Checkout what is being done with nanotechnology and building structures, Complex structures!, with dna strands!\n\nhttp://www.nature.com/nature/links/040212/040212-1.html\n\nIf it CAN and it can be measured imagine what can be done!\nalmost scary!
39430
Some believe that before DNA and protein, life existed in the form of RNA, evidenced by catalytic RNA in existence today (forming part of the ribosome: a protein building cellular machine) \n\nLess philosophically, amino acids (of which there are 20 types) are put together in sequences predetermined by DNA sequences. These DNA sequences are transcribed (copied) into an intermediary molecule of RNA, which is "read" by the ribosome (which gathers the correct amino acids to build the protein)
575480
The double helical structure of DNA is due to hydrogen bonding between the base pairs, therefore non-covalent.\n\nEach strand of DNA is a chain of nucleotides. The atoms of each nucleotide are held together by covalent bonds.
173265
DNA is a double helix, has deoxyribose sugar, and the nitrogen base thymine.\n\nRNA is a single strand, has ribose sugar, and the nitrogen base uracil (instead of thymine).
221648
The mode by which DNA replicates. Each strand acts as a template for a new double helix. The established model of DNA replication in which each double-stranded molecule is composed of one parental strand and one newly polymerized strand.
99741
Despite your poorly worded question, I think you are trying to ask if DNA refutes the idea of natural selection and evolution, right?  I think DNA, if anything, supports the idea of evolution.  In my simple understanding of evolution, I was able to take 1 protein from a turtle, human, lizard, snake, rat, monkey (using a protein/DNA sequence database, www.pubmed.com), and find how how different they are.  By using the accepted rate of mutation (1 base pair of DNA per million years), you can actually figure out how long ago did the species diverge simply based on random mutations.  By doing this, I made the evolutionary timeline that you see in textbooks all the time.  So in a way, I "proved" evolution by just doing something anybody can do with the resources available to me.\n\nThe part that I skip over in this program is that when a mutation is "bad" (something that would make it less likely to survive), that animal dies off.  Therefore, only "good" mutations will persist.  So when Watson and Crick in the 1950's "discovered" DNA, they in fact show how genes are passed on and how evolution can occur on a purely chemical level.\n\nI know this reply is a bit scattered, but if you do some research in scientific magazines/journals/text-books, evolution isn't some half-brained invention by anti-Christians (in fact most Evolutionists are Christians by the sheer fact that most Americans are Christian).  Evolution is a great theory in the sense it could easily be disproven, but it hasn't, therefore its the best we got until we find some greater truth.
481417
I could see 99%+.  I expect that they're doing a bit of statistical extrapolation (can't test everybody) and taking the upper range on their margin-of-error for journalistic sensationalism.  So, overall, probably.  \n\nConsider: DNA is DNA for every living thing (except perhaps a virus), so variations outside of a certain threshhold result in a different creature -- like aardvarks and komodo dragons.  Considering the diversity of life on earth, it should come as little surprise that the threshhold on DNA between one species and another is rather small (at least in comparison to the whole).
851956
First, kudos to you for being so open minded.\n\nI haven't read the Nat'l Geo article yet ... but I have it, and am anxious to read it.  Say what you will, the photos are breathtaking (but that's nothing new with Nat'l Geo).  And I have read several Dawkins books, but not that one. \n\nBut without hearing your specific counter-arguments, I don't know how to address them, or why you find the evidence to be "not of such high quality."  The evidence is actually *exceedingly* strong ... and most scientists accept it.\n\nI highly recommend two books in the "Beginners" series.  Specifically, "DNA for Beginners" and "Darwin for Beginners".   Don't be fooled by the cartoon format of these books ... they are excellent introductions to the science.\n\nBut if I can try and guess your point ... if the evidence of genetic linkage with *prehistoric* species is not of "high quality", it's because the DNA molecule (the source of all genetic material for all life on this planet) breaks down rather quickly.  Even a few hundred years is enough to start breaking down the DNA in the remains of animals.  And fossils rarely contain any genetic material.  However, this is not always true.  Occasionally, bone tissue can remain in fossils, and some DNA can be extracted (as we have done with Neanderthal, for example).  But overall, recovering genetic material from prehistoric animals is difficult.\n\nHowever, the genetic links can be reconstructed quite well by examining genetic similarities between living descendants of that prehistoric species.  If living species A, B, and C all have specific genes in common (code for the same protein, same location in the chromosomes, almost identical amino-acid structure), then this tells us that their common ancestor X had these genes.  If there is a fouth species D that has some, but not all the genes shared by A, B, and C ... then this indicates that there is a common ancestor Y that is further back that is the ancestor of all four living species.\n\nFuthermore, there is the concept of the 'molecular clock'.  This is the known rate at which transcription errors (basically 'typos') occur in DNA as it gets passed from generation to generation.  So the number of minor 'typos' found in the DNA of A, B, and C gives us a strong indication of how long ago their common ancestor X lived.  (For more info. see source.)\n\nI hope that helps.  It's hard to be more specific without knowing what your specific objections are.
273698
http://search.yahoo.com/search?p=shattered+helix+dna+of+humans&ei=UTF-8&fr=FP-tab-web-t&x=wrt  read through these to see if any of them are what you need
909726
are you asking a question here or are you trying to preach. well i don't deny the presence of God and i am quite a religious man. but i think it was quite a absurd way to manupilate the facts as you did. u have combined the holistic approach and the scientific approach to arrive at a pseudo conclusion. why are u using that -ve ion and positive ion theory. in fact if you look at the sperm, u will find thatit is nothing but a single strand of DNA with few protiens and yeah proteins are postively charged ions but the same protein are present in ovum too and infact in larger quantity than in sperm,, so the ovum is bound to be more positively charged, if we go by your hypothesis.\n\nbetter u correct your facts before you post.\n\nP.S: i would have answered longer still and would have posted thousands of doubt in your question if i would have time and patience to go through your question completely. but unfortunately i don't think it's worth my time to waste my energy on such a stupid question. \nyou are making the mockery of GOD as well as science
931396
There is no way that Darwin could have been aware of the specific molecule we call deoxyribonucleic acid (DNA). In the mid-eighteenhundreds Friedrich Miescher isolated "nuclein" and then purified it.  The substance was identified as an acid and named as such the same century.  It wasn't until 1929 that the components of DNA were identified and 1937 that an x-ray structure of the polymer was available.  Many people worked at solving the problem (an x-ray structure of a molecule isn't a real "map" like you might think of with bones, its more like a series of clues from which you might "back out" the structure with much difficulty) and in 1953 James Watson & Francis Crick published the seminal Nature paper detailing their proposed structure for DNA, a double-helix with a phosphate backbone and nucleoside interior having set "patterns" of left-right pairing.  \n\nThis was almost 100 years after Charles Darwin published Origin of Species (1859).  Darwin's proposal of evolutionary processes stemmed from observations of the macroscopic natural world and was based not on chemistry but primarily on phylogeny.  Darwin's concepts were utilitarian-based similar to Lamarck's proposals, but differed by rejecting inheritability of aquired characteristics, instead favoring a model where beneficial intrinsic characteristics would arise on their own but predispose their bearers for greater survival & reproduction.  \n\nA contemporary with Gregor Mendel, at the time he wrote his famous Origin of Species, Darwin was not aware of the work of Mendel on inheritance of traits.  However, both scientists' work supported the same conclusions.
241655
The only blood test that I have heard of relating to double-stranded DNA is an antibody test.  In certain autoimmune diseases, most commonly lupus, the body's immune system becomes activated against normal components of your body rather than what it should be attacking (foreign things).  In lupus, the body produces antibodies against double-stranded DNA (genetic material).  A positive lab test could indicate that the person has lupus.  With that said, lupus is a very complicated disease to diagnose.  They would never diagnose it based on a single positive lab test.  An immunologist or rheumatologist could explain in detail exactly what is needed to diagnose lupus.
429879
Each half of the double-helix sort-of "unzips" during replication.  Since each of the bases is kind of like a jigsaw-puzzle piece, the two strands can then wind back up, if supplied with the appropriate free bases, to form two identical copies of the original DNA strand.\n\nNeat, huh?
132431
You may need watson - creek structure\nDNA structure
534422
No possible way of knowing that since nobody (I am quite sure) has gone back and tried to determine whether the particular DNA evidence used in all those cases was "accurate" or "inaccurate."  In general, however, it is my belief that when performed properly and correctly used, DNA evidence is virtually infallible.