Where does DNA come from?
542692
It has to come from our Creator.\nAll the sequences and genes and chromosones that make up our body can not be a random factor.  There has to be purpose in all this, to make such a wonderful structure as the human body and keep all the genetic codes in place.\n\nIf you want the "Big Bang" theory, I am not for it... Anything that comes out of an explosion is demolition and destruction.  \nReminds me of a tornado in a junkyard theory, it doesnt produce any new machines, rearange parts for something new, it just destroys, rends and tears apart things.  \n\nThe atomic bomb didnt "create" anything new. It destroyed.\n\nSo, I attribute the DNA and RNA sequence to our Creator.\n\nJust my humble opinion...\n\nJesse
580739
DNA is transcribed into RNA (the so called messenger RNA, mRNA, to be exact). Like almost every other biochemical process, it is made possible by enzymes - in this case RNA-polymerases (we have three types, bacteria only one). It is able to "read" the template - being DNA - and use free nucleotides - the building blocks of nucleic acids - to create a complementary copy of RNA. DNA is a double stranded molecule (the famous double helix), mRNA has a single strand. This process takes place in the cell nucleus.
885739
It comes u from the genes that u inherit.  In fact it is true of the entire body.
1108483
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 many 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. DNA is thought to date back to between approximately 3.5 to 4.6 billion years ago [1].\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 color 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.
977995
One word contradicts your "facts". \n\nPlasmids.\n\nPlasmids are non-chromosomal loops of DNA found in bacteria.  They often contain antibacterial resistance genes, or give the ability to use different sugars.  These plasmids are commonly shared by bacteria.  This is a gain of genetic information.\n\nNow, it is true that we only have 4 types of nucleotides in DNA, and they make about 20 amino acids.  This is conserved in all life forms. But from this, a countless number of proteins can be made, and have a nearly infinite number of effects.  Your suggesting could be likened to saying that we can never invent a new word, since we only have 26 letters.  \n\nPlease provide a source for your claims, perhaps then we can understand how you arrived at such a conclusion.
189844
Science estimates that the first DNA forms of life were present on Earth around 3.5 billion years ago.
280647
"In nature, living things evolve through changes in their DNA. In an animal like a chicken, DNA from a male sperm cell and a female ovum meet and combine to form a zygote -- the first cell of a new baby chicken. This first cell divides innumerable times to form all of the cells of the complete animal. In any animal, every cell contains exactly the same DNA, and that DNA comes from the zygote. \n\nChickens evolved from non-chickens through small changes caused by the mixing of male and female DNA or by mutations to the DNA that produced the zygote. These changes and mutations only have an effect at the point where a new zygote is created. That is, two non-chickens mated and the DNA in their new zygote contained the mutation(s) that produced the first true chicken. That one zygote cell divided to produce the first true chicken. \n\nPrior to that first true chicken zygote, there were only non-chickens. The zygote cell is the only place where DNA mutations could produce a new animal, and the zygote cell is housed in the chicken's egg. So, the egg must have come first."
895545
This goes to the core of biological and evolutionary theory.\n\nDNA is elements arranged into nucleic acid molecules, arranged in a code (see first link). This code is directly used by a couple of RNA molecules to build protein molecules, ie enzymes (see link two).\n\nProtein molecules make up most of our body structure themselves, but for other parts (made from other molecules - which are combinations of elements), enzymes are used to arrange the correct structure.
514661
DNA is used to create many different kinds of protiens.  It is the template that your body uses to create them.
767356
new DNA...i dont know in new DNA but normal DNA is composed of sequences of Nucleotides which are molecules of sugar, Phosphate and a Nitric substance... sequences of predetermined Nucletides make genes...Humans have 46 chromosomes so we have 46 DNA Molecules....\n\nThis si complicated i could talk about 3 hours of DNA...why do u want to know that...this is advanced Molecular biology
950574
It's a key element in evolution, and comes about through modifications of an organism's DNA via radiation, chemical poisoning, or simple mischance in cell replication.  The daugther organism can inherit the modified DNA, and it may - or may not - give some advantage toward survival and subsequent reproduction.
376786
They get DNA from nucleated cells like white blood cells (in blood and saliva) and epithelial cells (in saliva). They lyze the cells to free the DNA, centrifuge and take the fraction with the DNA, treat and amplify or multiply the DNA fragments, put markers or specific labels, determine the presence and amount of this marked or labeled fragments, and compare the distribution with known samples or DNA database. DNA results are usually one page long.
305731
Just a clarification-DNA is composed of nucleic acids, not amino acids.  Amino acids are the building blocks of proteins.
857229
they think that they evolved from bacteria.  Mitochondria and chloroplasts have their own DNA and manufacture some of their own proteins, like bacteria. It is thought that the mitochondria and chloroplasts evolved from symbiotic bacteria that took up residence inside the first eukaryotic cells.
592029
rna is copy of the dna used in transcription (i think) then it's translated back into dna somewhere else in the cell
292443
Your genetics..dna..you know..the whole human biology thing..
625092
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.