Approatch to DNA aAlgorithms

Our body's cells each contain a complete sample of our DNA.  One cell is roughly equal in size to the cube described in the previous paragraph.  There are muscle cells, brain cells, liver cells, blood cells, sperm cells and others.  Basically, every part of the body is made up of these tiny cells and each contains a sample or complement of DNA identical to that of every other cell within a given person.  There are a few exceptions.  For example, our red blood cells lack DNA.  Blood itself can be typed because of the DNA contained in our white blood cells.  

Not only does the human body rely on DNA but so do most living things including plants, animals and bacteria.  

A strand of DNA is made up of tiny building-blocks.  There are only four, different basic building-blocks.  Scientists usually refer to these using four letters, A,  T,  G,  and C.  These four letters are short nicknames for more complicated building-block chemical names, but actually the letters (A,T, G and C) are used much more commonly than the chemical names so the latter will not be mentioned here.  Another term for DNA's building blocks is the term, "bases."  A, T, G and C are bases. 

Now, the people have already understood basically how heredity is take place.20 centuries of the biology research detection:The human body is to be constitute by the cell of, the cell is constitute by the cell membrane, the cell quality and cell nucleus etc..Have already in the cell nucleus know to have a kind of material to call chromosome, it mainly is constitute by some materials that be called to take off the oxygen pit  sugar nucleic acid( DNA).

DNA or RNA is a nucleic acid polymer consisting of nucleotide monomers that plays several important roles in the processes that translate genetic information from deoxyribonucleic acid (DNA) into protein products; RNA acts as a messenger between DNA and the protein synthesis complexes known as ribosomes, forms vital portions of ribosomes, and acts as an essential carrier molecule for amino acids to be used in protein synthesis. RNA is very similar to DNA, but differs in a few important structural details: RNA nucleotides contain ribose sugars while DNA contains deoxyribose and RNA uses predominantly uracil instead of thymine present in DNA. RNA is transcribed (synthesized) from DNA by enzymes called RNA polymerases and further processed by other enzymes. RNA serves as the template for translation of genes into proteins, transferring amino acids to the ribosome to form proteins, and also translating the transcript into proteins

RNA is a polymer with a ribose and phosphate backbone and four different bases: adenine, guanine, cytosine, and uracil. The first three are the same as those found in DNA, but in RNA thymine is replaced by uracil as the base complementary to adenine. This base is also a pyrimidine and is very similar to thymine. Uracil is energetically less expensive to produce than thymine, which may account for its use in RNA. In DNA, however, uracil is readily produced by chemical degradation of cytosine, so having thymine as the normal base makes detection and repair of such incipient mutations more efficient. Thus, uracil is appropriate for RNA, where quantity is important but lifespan is not, whereas thymine is appropriate for DNA where maintaining sequence with high fidelity is more critical.

However, there are also numerous modified bases and sugars found in RNA that serve many different roles. Pseudouridine (Ψ), in which the linkage between uracil and ribose is changed from a C–N bond to a C–C bond, and ribothymidine (T), are found in various places (most notably in the TΨC loop of tRNA). Thus, it is not technically correct to say that uracil is found in RNA in place of thymine. Another notable modified base is hypoxanthine (a deaminated Guanine base whose nucleoside is called Inosine). Inosine plays a key role in the Wobble Hypothesis of the Genetic Code. There are nearly 100 other naturally occurring modified nucleosides, of which pseudouridine and nucleosides with 2'-O-methylribose are by far the most common. The specific roles of many of these modifications in RNA are not fully understood. However, it is notable that in ribosomal RNA, many of the post-translational modifications occur in highly functional regions, such as the peptidyl transferase center and the subunit interface, implying that they are important for normal function.

Single stranded RNA exhibits a right handed stacking pattern that is stabilized by base stacking. [reference?]

The most important structural feature of RNA, indeed the only consistent difference between the two nucleic acids, that distinguishes it from DNA is the presence of a hydroxyl group at the 2'-position of the ribose sugar. The presence of this functional group enforces the C3'-endo sugar conformation (as opposed to the C2'-endo conformation of the deoxyribose sugar in DNA) that causes the helix to adopt the A-form geometry rather than the B-form most commonly observed in DNA. This results in a very deep and narrow major groove and a shallow and wide minor groove. A second consequence of the presence of the 2'-hydroxyl group is that in conformationally flexible regions of an RNA molecule (that is, not involved in formation of a double helix), it can chemically attack the adjacent phosphodiester bond to cleave the backbone.

 Comparison with DNA

Unlike DNA, RNA is a single-stranded molecule in most of its biological roles and has a much shorter chain of nucleotides. RNA contains ribose, rather than the deoxyribose found in DNA (there is no hydroxyl group attached to the pentose ring in the 2' position whereas RNA has two hydroxyl groups). These hydroxyl groups make RNA less stable than DNA because it is more prone to hydrolysis. Several types of RNA (tRNA, rRNA) contain a great deal of secondary structure, which help promote stability.

Like DNA, most biologically active RNAs including tRNA, rRNA, snRNAs and other non-coding RNAs (such as the SRP RNAs) are extensively base paired to form double stranded helices. Structural analysis of these RNAs have revealed that they are not, "single-stranded" but rather highly structured. Unlike DNA, this structure is not just limited to long double-stranded helices but rather collections of short helices packed together into structures akin to proteins. In this fashion, RNAs can achieve chemical catalysis, like enzymes. For instance, determination of the structure of the ribosome in 2000 revealed that the active site of this enzyme that catalyzes peptide bond formation is composed entirely of RNA.

Synthesis
Synthesis of RNA is usually catalyzed by an enzyme - RNA polymerase, using DNA as a template. Initiation of synthesis begins with the binding of the enzyme to a promoter sequence in the DNA (usually found "upstream" of a gene). The DNA double helix is unwound by the helicase activity of the enzyme. The enzyme then progresses along the template strand in the 3’ -> 5’ direction, synthesizing a complementary RNA molecule with elongation occurring in the 5’ -> 3’ direction. The DNA sequence also dictates where termination of RNA synthesis will occur.

There are also a number of RNA-dependent RNA polymerases as well that use RNA as their template for synthesis of a new strand of RNA. For instance, a number of RNA viruses (such as poliovirus) use this type of enzyme to replicate their genetic material. Also, it is known that RNA-dependent RNA polymerases are required for the RNA interference pathway in many organisms.

Biological roles
The single-stranded DNA (ssDNA)-binding protein replication protein A (RPA) is essential for both DNA replication and recombination. Chromatin immunoprecipitation techniques were used to visualize