what is dna?how does it work?

Answer 1

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.

In 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.

DNA 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.

Every 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.

Answer 2

DNA is a polymer and it is the genetic blue print for how the body works and reproduces.The simplest unit of DNA is called a nucleotide. In each nucleotide a nitrogen-containing base (ring structure), a phosphate group which is the backbone, deoxyribose which is a sugar are linked. The nucleotides are linked to each other through the phosphate backbone creating a single strand. Two strands of DNA are bonded together in the middle with hydrogen bonds linking matching base pairs together. Double-stranded DNA is helical in shape, known as the double helix. Think of it as a twisted zipper.
If you want to know how it works, you'll have to go read a book on it, or at least a few chapters in a high school biology text. I'll try to give you a very generalized idea of how it works.
But in brief, DNA has two main functions: 1) to reproduce itself in somatic (body) cells and to create gametes (sex calls) in organisms that reproduce sexually. 2) to code for all the proteins and enzymes that are needed in the cells and in the body.
In order to accomplish #1, a doubled strand of DNA unzips itself like a zipper and makes a copy of the whole strand with the help of enzymes. In order to do job #2, the zipper unzips but a copy is made of of only part of the DNA strand, and it is made in messenger RNA. That mRNA goes to a ribosome(s) and runs through it like a tape going through a tape recorder. Out the other end comes a protein molecule or a precursor of it. This is completely over-simplified, but I have to assume you know nothing about DNA when I answer this question.

Answer 3

The initials stand for 'deoxyribonucleic acid', found in the cells of all living things, including the human body. The DNA is a very long molecule and is found in the nucleus of cells.

Although each person's DNA is unique (unless he/she has an identical twin), the techniques for identification only look at small parts of the DNA.

It is important to realise that a person will have the same DNA throughout their body in every cell with a nucleus. That is, the same DNA profiling results for one person will be obtained whether testing blood or semen or muscle tissue.
Structure of DNA

The DNA molecule actually consists of two strands twisted about each other in the shape of a spiral staircase (double helix). The building blocks of the strands are referred to as bases. There are four different types of bases in the DNA molecule and it is the sequence of these that determines our inheritable characteristics. The bases from each strand bind to each other, holding the molecule together as in the stairs on a spiral staircase. As each type of base will only bind with another specific type, the two strands are said to be 'complementary'. Two bases binding together are referred to as a base pair (bp).


DNA profiling results mean for a case..DNA profiling does not claim to be absolute identification, but may be very strong evidence, and generally forms just one part of a case. It is really a question of looking at all the evidence in the case such as; who had the opportunity to commit the crime, eye-witness descriptions, fingerprints, the transfer of glass fragments, paint flakes or fibres linking a person to a crime and the DNA profiling results. DNA profiling is presented to the court as in the example above and the jury or magistrate can draw their own conclusions, as they do about all the evidence...DNA profiling used?

It depends on many factors. DNA profiling is typically carried out when human biological fluid or tissue is found at a crime scene and used as evidence to link to, or exclude from, that scene, a possible suspect. Some examples are:

A murder where it appeared that a struggle took place and blood from the murderer was left at the scene. This would be compared to a sample of blood from the suspect.

A murder where a blunt instrument was used and a suspect was found with a club on which there were dried blood stains. The blood on the club would be compared to the victim's blood.
A rape case where seminal fluid from the offender can be taken from the victim. This would be compared to a sample of blood from a suspect.
DNA profiling can only be used if there is enough DNA in the samples, and is only useful in comparing samples. Crime samples can be compared to a sample from a known suspect or compared to a database of DNA profiling results from other scenes or from convicted offenders. If there is a 'match', the two samples may have originated from the same person.

DNA profiling can be a very powerful investigative tool. Of the cases carried out so far, approximately fifty percent of the profiling results have established that the suspect was not the source of the sample associated with the crime - i.e. he/she was excluded as being the perpetrator of the crime.

Answer 4

DNA codes for proteins.Proteins are made up of units called amino acids. I like to think of a cell as a house. The amino acids are the bricks, cement, timber frame and tiles etc. The DNA is the blueprint that tells the amino acids how to form proteins. The proteins are the structures of the cell and parts that help it to move.

Answer 5

DNA stands for DeoxyribonucleicAcid.

Answer 6

hi

DNA can b used to detect diseases, improve crops, or catch criminicals. The Information in DNA sequences has been harnessed for a multitude of tasks.

For more Visit:

http://www.koshlandsciencemuseum.org/exhibitdna/index.jsp

Answer 7

it is deoxyribonucleic acid.
it is the genetic code that specifies how our cells should develop
more specifically it decides what kind of proteins should get produced and should be contained in our cells
each of our dna is slightly different and that gives us our individuality

Answer 8

Substance carrying organism's genetic information-a nucleic acid molecule in the form of a twisted double strand (double helix) that is the major component of chromosomes and carries genetic information.
Full form is deoxyribonucleic acid.

Answer 9

DNA?
Dude No Answer.

Answer 10

it is a genetic make up of your body it makes you you