how does DNA replicate?
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Before a cell can divide, it must duplicate all its DNA. In eukaryotes, this occurs during S phase of the cell cycle. \n\nA portion of the double helix is unwound by a helicase. \nA molecule of a DNA polymerase binds to one strand of the DNA and begins moving along it in the 3' to 5' direction, using it as a template for assembling a leading strand of nucleotides and reforming a double helix. In eukaryotes, this molecule is called DNA polymerase delta (δ). \nBecause DNA synthesis can only occur 5' to 3', a molecule of a second type of DNA polymerase (epsilon, ε, in eukaryotes) binds to the other template strand as the double helix opens. This molecule must synthesize discontinuous segments of polynucleotides (called Okazaki fragments). Another enzyme, DNA ligase I then stitches these together into the lagging strand. \n\nWhen the replication process is complete, two DNA molecules — identical to each other and identical to the original — have been produced. Each strand of the original molecule has \nremained intact as it served as the template for the synthesis of \na complementary strand.\nThis mode of replication is described as semi-conservative: one-half of each new molecule of DNA is old; one-half new
413070
Alternatively, if you meant why do cells stop dividing after a certain time it is because their telomeres get too short. Telomeres are the parts of DNA at the end of chromosomes. DNA polymerase requires a primer (a piece of DNA to sit on). It starts making new DNA from this point, but doesn't copy the part it sits on at first, so the copy is a tiny bit shorter than the original. Each time cells divide and copy their DNA, their telomeres get a little bit shorter. When they are too short the cell recognizes this and stops dividing.
286365
DNA is a double helix molecule.  The 2 strands are aniparellel (one runs 3' to 5' and the other 5' to 3').  The DNA says in the nucleus of the cell.  The way it replicates is that in uncoils itself and separated from the other strand.  Because of the 4 different nucleotides it is simple to replicate.  The nucleotides are shown as A,C,T, and G.  G goes with C, and T goes with A.  After the stands have separated the nucleotides that are floating about attach themselves to the proper match.  They attach themsleves using an enzyme called DNA polymerase. Now you have 2 complete DNA strands.
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Deoxyribonucleic acid (DNA) is a nucleic acid —usually in the form of a double helix— that contains the genetic instructions specifying the biological development of all cellular forms of life, and most viruses. DNA is a long polymer of nucleotides (a polynucleotide) and encodes the sequence of the amino acid residues in proteins using the genetic code, a triplet code of nucleotides.\n\nIn complex eukaryotic cells such as those from plants, animals, fungi and protists, most of the DNA is located in the cell nucleus. By contrast, in simpler cells called prokaryotes, including the eubacteria and archaea, DNA is not separated from the cytoplasm by a nuclear envelope. The cellular organelles known as chloroplasts and mitochondria also carry DNA.\n\nDNA is often referred to as the molecule of heredity as it is responsible for the genetic propagation of most inherited traits. In humans, these traits can range from hair colour to disease susceptibility. During cell division, DNA is replicated and can be transmitted to offspring during reproduction. Lineage studies can be done based on the facts that the mitochondrial DNA only comes from the mother, and the male Y chromosome only comes from the father.\n\nEvery person's DNA, their genome, is inherited from both parents. The mother's mitochondrial DNA together with twenty-three chromosomes from each parent combine to form the genome of a zygote, the fertilized egg. As a result, with certain exceptions such as red blood cells, most human cells contain 23 pairs of chromosomes, together with mitochondrial DNA inherited from the mother.\n\nThe discovery that DNA was the carrier of genetic information was a process that required many earlier discoveries. The existence of DNA was discovered in the mid 19th century. However, it was only in the early 20th century that researchers began suggesting that it might store genetic information. This gained almost universal acceptance after the structure of DNA was elucidated by James D. Watson and Francis Crick in their 1953 Nature publication. Watson and Crick proposed the central dogma of molecular biology in 1957, describing the process whereby proteins are produced from nucleic DNA. In 1962 Watson, Crick, and Maurice Wilkins jointly received the Nobel Prize for their determination of the structure of DNA.
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It is not possible to divide a cell without replicating its DNA. This is how it works: DNA replicates during interphase. So now we have two copies of the same genetic material. These two copies then split apart into two cells in mitosis and cytokinesis. The result is two identical cells with the same genetic material as the parent cell.\n\ndid it help, or make it more confusing?
68378
I think what you're looking for has to do with replication. Every time the cell goes through mitosis to divide, it has to make an exact copy of all the DNA in the cell, so that there are two complete copies, one for each daughter cell. The process of replication and division is the cell cycle.\n\nIn replication, a complex of enzymes copies the DNA by unzipping the double helix to expose the single strands. Someone else mentioned A-T C-G bair pairing and that is correct. The four subunits in DNA are the bases, and they are abbreviated A,T,C and G. Just by the shape of the molecules, A will connect with T and C with G pretty much always (though there are exceptions that are beyond the scope of a general explanation). \n\nSo in replication, enzymes pull the two strands of the double helix apart in short regions, pulling apart the A-T C-G bair pairing. It is energetically unfavorable to have a single strand of DNA exposed and not base paired. Free nucleotides in the cell will come in and form hydrogen bonds with the exposed template strand (it will happen on both strands), and then enzymes will connect the newly deposited bases with phosphodiester linkages to form a new DNA molecule. This forms a new strand of what is called duplex DNA, meaning it is a new double helix. The complementarity of the base pairs drives replication to produce an exact copy of each part of the genetic code. The error rate is very low, but errors can and do occur, and there is proofreading machinery to check for mistakes and excise and replace incorrect base pairs.\n\nPictures are helpful...in the second link, scroll down to see the replication bubble. A replication fork and a replication bubble are essentially the same thing...it's the site where the double helix is open and replication is occurring.
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if you meant growth rate the the answer is that it is very variant and can be as short as 20 min or as long as 3 hr and more. as for the phases of the cycle- it just multiply it's DNA as fast as it can and splits into half.
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It's a process where DNA is moved and separated by electrical currents bands are formed on a gel called agarose.  It shows similarities and differences between relations and non relatives.  The gel created is unique to you and therefore is how DNA testing can tell if the DNA supplied came from a certain source
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Are you asking about DNA causing itself to be assembled?
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I gave a lecture on this recently and have had first hand experience with this technology in a lab, so let me give you a brief and easy summary to take with you about this topic about Recombinant DNA Technology:\n\nIn order to clone you need 2 things: Bacterial DNA (the circular form called a "plasmid"), and the DNA you want to clone (be it human, mouse, plant, other species etc)\n\nThen you will need to cut the Bacterial DNA with enzymes called "endonucleases" that work like scissors. (So imagine a circle and I take a pair of scissors and cut the circle at some point in it, b/c I want to insert the foreign DNA (non native DNA) where I had cut.) I will have to do the same with the foreign DNA and have endonucleases cut OUT the particular piece i want cloned. \n\nThen we can put the two pieces together, the cut circular plasmid DNA from the bacteria, and the CUT out piece of foreign DNA. \n\nWhen we put the two pieces together it is called "ligation", and it is done as a reaction in a tube with enzymes inside that "glue" the "sticky ends" of the bacteria DNA to the foreign DNA. \n\nAfter the reaction normally done in a 16 deg. Celsius water bath, we now will have "circular" plasmids with our Foreign DNA inserted into the bacterial DNA (the circle DNA)\n\nThen we would re-insert this DNA back into the bacterial host (that the circle DNA first came out of) in a process called "transformation", this is where the broth from the water bath we just discussed is grown in a growth medium at 37 deg. celsius so that the bacteria can grow and produce MORE of those circle plasmids with our foreign DNA inserted into it. \n\nThen we would "plate" these onto agar plates, and let them grow in incubators at 37 deg. Celsius over night until we get small colonies of bacteria on the plate. \n\nEach "mound" of bacteria (small like white dots on the plate) contains millions of copies of our gene (inserted in the circular plasmid DNA of the bacteria). \n\nNow we can take these small colonies, and harvest them further, by putting them in large Erlenmeyer flasks to be grown in the same "growth broth" over night on a shaker for 37 deg. celsius. \n\nAfter of which we can harvest, and purify that culture so that only the circular plasmids remain (this is a long and convuluted process so we won't go into it in detail here), and from there you can store those in a 4 deg. Celsius fridge and keep it in stock for further research purposes. \n\nHope that helps!
19715
DNA replication is not organism dependent. It involves 3 basic steps, initiation, replication, and termination. More detailed information is below.
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I am only positive on question 4, the okazaki fragments as you probably know are the fragments that are made when replicating DNA away from the replication fork, the DNA strand is replicated by DNA Polymerase, which is one part, and since the DNA is anti-parallel and you must add on to the 3 prime end the DNA strand has to be flipped over the Polymerase, to keep the strand going in an orderly fashion.  The reason it is necessary is because DNA polymerase builds in one direction and since DNA is anti-parallel, one must be made in another way to accommodate for this.
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its a double helix.\n\n  \n 1. DNA is made up of subunits which scientists called nucleotides.\n   2. Each nucleotide is made up of a sugar, a phosphate and a base.\n   3. There are 4 different bases in a DNA molecule:\n\n          adenine (a purine) \n          cytosine (a pyrimidine) \n          guanine (a purine) \n          thymine (a pyrimidine) \n\n   4. The number of purine bases equals the number of pyrimidine bases\n   5. The number of adenine bases equals the number of thymine bases\n   6. The number of guanine bases equals the number of cytosine bases\n   7. The basic structure of the DNA molecule is helical, with the bases being stacked on top of each other
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no....the clone is started with a single cell.....the dna is removed from one cell of the donor and place into the cell of a uterine egg cell.  The new cell is then zapped with low amounts of electricity to get the dna to start doing its job of replicating.....since the dna used is a blue print of what the makes up the  donor the new egg will develop into an identical image of the original.  But will be a younger version if it lives.....this process must be done hundreds of times if not more to get even one cell that survives the process and can live/replicate the way it should.
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Ahh...thats easy...After putting the DNA in the holes, and turning on the electric field, DNAs move to the (+) pole because they have a (-) charge....Small DNAs move faster and they separate so the result is seen on the gel...
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A virus needs a cell to replicate itself. You see viruses have absolutely no ability to reproduce on there own. They basically "hijack" a cell and then the cell makes a copy of the virus.
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Replication of DNA occurs in the "S" phase (or Synthesis phase) of the cell cycle process. Usually, people perform cell cycle analysis on cells fixed at progressively differing time points. In our laboratory, we fix our cells with 70% EtOH at 0, 12, 18, 24, and 48 hours. Then we use a FACS calibur machine to visualize and quantify the percentage of cells in each phase of the cell cycle.