correct spelling ..replication and it is DNA replication begins with a partial unwinding of the double helix at an area known as the replication fork. This unwinding is accomplished by an enzyme known as DNA helicase. This unwound section appears under electron microscopes as a "bubble" and is thus known as a replication bubble
2006-10-08 05:19:39
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answer #1
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answered by doctor asho 5
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DNA replication or DNA synthesis is the process of copying a double-stranded DNA strand in a cell, prior to cell division. In eukaryotes, this is during the S phase of the cell cycle, preceding mitosis and meiosis. The two resulting double strands are identical (if the replication went well), and each of them consists of one original and one newly synthesized strand. This is called semiconservative replication. The process of replication consists of three steps, initiation, elongation and termination. Artificial DNA replication is carried out through polymerase chain reaction.
The main purpose of replication is to create a single exact duplicate copy of a genome. This task is facilitated by the basic complementary nature of DNA, which allows one single-stranded piece of DNA to serve as a template for a new, complementary strand, simply by pairing up matching bases against the template strand. The fundamental polymerization reaction (elongation), which consists of the addition of a single base to a nucleic acid chain, relies on a simple feature of nucleotide chemistry. The necessary reagent is a nucleoside triphosphate (NTP), which consists of a single nucleotide (i.e., A, T, G or C for DNA) with a tri-phosphate chain attached to the 3' OH group on the nucleotide's [deoxy]ribose sugar. Such triphosphates are high-energy molecules, and in fact the nucleoside triphosphate ATP (adenosine triphosphate) is the common energy currency of the cell. The elongation reaction is the formation of a phosphodiester bond, which is formed when the 5' hydroxyl group of last deoxyribose in the nucleic acid chain attacks the first (α) phosphate group of the NTP to be added; the last two phosphates are removed, leaving a stable phosphate bridge linking the 5' oxygen of one nucleotide to the 3' oxygen of the new nucleotide. Note that this reaction MUST proceed in a 5' to 3' direction - if the elongation reaction were to take place the other way, the 5' OH of the free nucleotide would have to attack the triphosphate chain on the 3' end of the elongating chain. If this triphosphate were at any point hydrolyzed and reduced to a single phosphate (a likely event, since it is highly energetically favorable and triphosphates are unstable), the reaction would stall. The 5' to 3' elongation, on the other hand, has a stable reactant (a free hydroxyl group) and requires only a free NTP, which are readily available in the cell.
2006-10-08 12:20:16
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answer #2
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answered by Anonymous
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DNA is the genetic material in the nucleus of every cell that contains the genetic code of every protein that cud be produced in the body.Proteins are responsible for all characters and functions in the body.when a cell divides mitotically,the DNA is one of the components that needs to be copied into the newly formed cell.Hence DNA undergoes SELF DUPLICATION(replication).Thus 1DNA produces Another DNA.
2006-10-08 12:28:45
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answer #3
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answered by narasimham b 1
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it's a process where 2 folds of dna strand unfold and each of the strands produce a copy of themselves by combining to specific bases. this pairing is specific and ultimately 2 copies of DNA are formed
2006-10-09 04:19:18
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answer #4
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answered by meetmickeymoon 2
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Making replica of it i.e. DNA makes another DNA.
2006-10-09 07:08:35
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answer #5
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answered by dinu 3
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its reproduction of DNA
2006-10-08 12:38:10
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answer #6
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answered by apurba s 3
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go to mcgrawhill.com
2006-10-08 12:23:09
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answer #7
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answered by wjleong15 2
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