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Deoxyribonucleic acid (/diˈɒksiˌraɪboʊnjʊˌkliːɪk, -ˌkleɪɪk/; DNA) is a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and RNA are nucleic acids; alongside proteins, lipids and complex carbohydrates (polysaccharides), they are one of the four major types of macromolecules that are essential for all known forms of life. Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix.
The two DNA strands are termed polynucleotides since they are composed of simpler monomer units called nucleotides. Each nucleotide is composed of one of four nitrogen-containing nucleobases—cytosine (C), guanine (G), adenine (A), or thymine (T)—a sugar called deoxyribose, and a phosphate group. The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two separate polynucleotide strands are bound together, according to base pairing rules (A with T, and C with G), with hydrogen bonds to make double-stranded DNA. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037 and weighs 50 billion tonnes. In comparison the total mass of the biosphere has been estimated to be as much as 4 trillion tons of carbon (TtC).
DNA stores biological information. The DNA backbone is resistant to cleavage, and both strands of the double-stranded structure store the same biological information. This information is replicated as and when the two strands separate. A large part of DNA (more than 98% for humans) is non-coding, meaning that these sections do not serve as patterns for protein sequences.
The two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases (informally, bases). It is the sequence of these four nucleobases along the backbone that encodes biological information. RNA strands are created using DNA strands as a template in a process called transcription. Under the genetic code, these RNA strands are translated to specify the sequence of amino acids within proteins in a process called translation.
Within eukaryotic cells DNA is organized into long structures called chromosomes. During cell division these chromosomes are duplicated in the process of DNA replication, providing each cell its own complete set of chromosomes. Eukaryotic organisms (animals, plants, fungi, and protists) store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts. In contrast prokaryotes (bacteria and archaea) store their DNA only in the cytoplasm. Within the eukaryotic chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.
DNA was first isolated by Friedrich Miescher in 1869. Its molecular structure was identified by James Watson and Francis Crick in 1953, whose model-building efforts were guided by X-ray diffraction data acquired by Raymond Gosling, who was a post-graduate student of Rosalind Franklin. DNA is used by researchers as a molecular tool to explore physical laws and theories, such as the ergodic theorem and the theory of elasticity. The unique material properties of DNA have made it an attractive molecule for material scientists and engineers interested in micro- and nano-fabrication. Among notable advances in this field are DNA origami and DNA-based hybrid materials.

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    NSW Process for child support when DNA test done without court order

    Scenario: A DNA test accredited by NATA is being arranged by proposed father from an affair, in order determine if actual father the baby.This is being done before any court order for paternity. Affair partner went ahead with giving birth to miracle child knowing father not wanting to father a...
  2. A

    NSW Paternal DNA help!!!!!!!!!

    Baby 11months old. Woman says my partner is the father. My partner and I have never denied that he isn’t. Problem is she won’t Allow him to meet the baby or spend time with him. Sends photos all the time.. tells him how the baby is going.. how does my partner go about getting a DNA test done is...
  3. A

    QLD Legal dna test now what?

    Hello I've finally received the legal dna test from my son's father after months of negotiating it but I'm unsure how to get that he's the father recognised by child support even with this test. I should note I have the highest level DVO against him covering myself and my son as he's abusive...
  4. S

    NSW DNA test to prove you are the father.

    Hi all, I'll try and make this brief, A friend of mine (male) was in a relationship with a girl for sometime and upon the relationship ending he found out she was pregnant. She refused to talk to him, denied he was the father and refused to put him on the birth certificate and has cut all...
  5. C

    TAS Corrupt DNA test is it possible

    Is it possible for a person to rig a court orderd DNA test? Has it ever happened to anyone or is it to hard.
  6. J

    QLD Paternity Fraud - Mother refuses DNA Tests

    Hi, I have a strange problem and would love some direction. An ex of mine told Child Services I was the father of two of her children (this started 8 yrs ago). Child Services called my employer (father-in law) for pay docking but I was a sub-contractor so they couldn't do anything. This was the...
  7. M

    QLD Negative paternity DNA test query

    i have recently completed a DNA test to confirm that I am not the father of a child I was alleged to be. My questions are: 1. Am I legally allowed to request the mother and son complete a statutory declaration saying they accept the negative result and will not contest things such as my will...
  8. J


    I wish to get my name on my daughter's birth certificate the mother refuses to let this happen . She has it listed as father unknown. When she knows I am the father . What is the first step I take ?? Any help would be greatly appreciated . Jarrod .