Is DNA of identical twins exactly the same?
397057
I just want to point out the fact that xaviar's and gradwrkout's answers are both very good.  Identical twins are spawned from a single set of DNA, so in theory, they are completely identical.  Some cells will vary due to mutations during DNA replication and other DNA mutating events, but mostly they will be identical.\n\nHowever, epigenetics can change throughout a person's lifetime, without altering the actual base-pairs of DNA.  Epigenetic changes include DNA CpG methylation, which can silence certain genes, and is common in certain cancers.  Another example of an epigenetic change has to do with chromatin.  Chromatin is what DNA is called when it is bound to histone core proteins.  When people talk about chromosomes, the chromosomes are always bound to histone.  The histone cores have little protein tails that can be altered in certain ways, which affects when a gene can be transcribed/translated.  Epigenetic changes can occur based on how you live your life-- if one twin lives in california and the other in london, the differences in their lifestyles will reflect in epigenetic changes.  Everything from diet and exercise to sleeping, etc, affects epigenetics.\n\nSo to answer the question, yes, their DNA is essentially identical, but over the course of their lifetimes, epigenetic changes can make them significantly different.  Also, just fyi, epigenetic changes are heritable.
754868
Hi! I'm the mother of identical twins.  Here's some facts:\n\n1. Identical twins occur when one fertilized egg splits.  It's a random act of nature and is not impacted by family history, age, ethnicity or fertility drugs.  Every pregnancy has a 1 in 250 chance of being identical twins.  Identical twins have the exact same DNA.\n\n2. Fraternal twins occur when the female produces two eggs and both are fertilized.  It can be influenced by family history or fertility drugs.  Advanced age or certain ethnicities also increase your chance of fraternal twins.  Fraternal twins are essentially brothers/sisters who happen to be born at the same time.  \n\nHope this helps.
687236
A clone is a group of identical genes, cells, or organisms derived from a single ancestor. For example a living thing.\n\nA copy refers to a reproduction of a photo, copy, or other pieces of work.
7536
Identical twins develop when a single fertilized egg splits in two, leading to two embryos. Because they both came from the combination of the same egg and sperm, they have identical DNA, barring the generally undetectable micromutations that begin as soon as cells start dividing. To a standard DNA analysis, they would be indistinguishable. Yet the parents of twins can usually tell them apart by subtle visual cues, and, while their fingerprints are generally similar, they are not identical.
835382
Cloning is the creation of an organism that is an exact genetic copy of another. This means that every single bit of DNA is the same between the two.
201829
that's not the case, i've read in newspapers instances of twins taking exams and getting the exact same score - i think they're as smart as each other.
584877
It's not expected to be the same. \n\nIn double stranded DNA, A=T and C=G, therefore (A+C)/(G+T) = 1 always. The number of A is not necessarily equal as C. Therefore, (A+T)/(C+G) can be any number, different than 1.
1023371
The answer is 6.3 billion (the population of the Earth) minus any identical twins. \n\nHumans have 3 billion base pairs of DNA, most of which are identical. To get to a number of possible differences, one would have to add up each set of one difference, two differences, etc. Here is an example with a smaller DNA sequence:\n\nGCT\nIn the first position, one can have three other nucleotides, C,A, or T. Ditto with the second position, and third position. But on top of this we have to count the sequences that differ at any two positions, and at all three positions.\n\nMathematically, this is 4*4*4, so just for three base pairs we have 64 possibilities.\n\nTherefore with 3 billion positions the answer is 4 raised to the 3 billionth power; 4^3000000000. This number is impossibly huge to comprehend. By comparison, a googol is 10^100, itself larger than the number of particles in the Universe. \n\nAnd this only counts point mutations. There are nearly infinite number of insertion and/or deletion mutations that can occur on top of the point mutations.
494213
With identical twins - the other twin will always be female, as they are a clone of the original female.\nWith the fraternal twin - the other will be either female or male 50/50.
492162
its true that no two person can have the same DNA...\n\nbut the determination of parental disputes is not done by matching the DNA but by matching the small sequences present on the DNA known as Genes...\n\na collection of a set of genes on DNA is called chromosome..\n\nsince a child has 50% characteristics of both the father and the mother, he has the same set up of genes in his/her chromosomes.. on the chromosomes, there are many sites which are exclusive to that set of gene and chromosome and are known as VNTR's VARIABLE NUMBER TANDEM REPEATS...\n\nthese sites are very unique, they differ from person to person but remain in the same place in a lineage.... this very property of the genes on the chromosome containing DNA accounts for the determination of parental disputes..\n\n\nfor eg:   suppose in gene A, of Chromosome 1 ur mom has 5 VNTR alternatively and ur dad had 3...\n\nso if u a guy then u'll have the same 3 VNTR's on the gene containing chromosome..\n\nas simple as that..\n\nhope u got the point...
1162458
I think he means clone.\n\nIt would be murder.\n\nJust because you have the same genetic code (as does an identical twin) doesn't mean you're the same person.
975799
A clone genetically is no different than an identical twin. Both the clone and the original person come from the same DNA. The only difference is that the clone will be younger than the original person, as they were created later. All the same nature vs nurture principles apply to the clone as they do to any person or set of identical twins. Your environment has a lot to do with shaping your personality. Twins (and clones) personalities may be similar in many ways, but they will never be identical. Neither will live their lives having the exact same experiences or thinking the exact same way. A clone would have their own "soul" (if that is the term you like to use) as much as two twins have their own separate souls. Identical twins are nature's clones.
674863
I support the research on human cloning. The clones would be individuals just like the rest of us--there is more to what makes a person who they are than their genes. Look at identical twins--they share the exact same genome yet they are not exact copies of one another in experience, personality, skills, etc. \nI think the pertinant question is this: What are the ethical rules to follow when it comes to human cloning?
996156
Never, just like their DNA, and the shape and structure of their eyes, their finger prints will not be the same, some time there are born identical twins to parent that look alike 99.9% but the only thing that make them different is that .1% and their DNA and finger prints, it is just a divine way of God creating his creatures,
912251
A very good question from your nephew\nNature provides us with the natural form of clones:\nidentical twins share the same genetic makeup and even\ndeveloped in the same uterus. Nevertheless, their\nfingerprints are not identical, though similar. The\nformation of fingerprints is partly the result of a\nstochastic process.\nThe ultimate shape of fingerprints are believed to be influenced by environmental factors during pregnancy, like nutrition, blood pressure, position in the womb and the growth rate of the fingers at the end of the first trimester. \n\n\nSo identical twins and clones are similar and they have similar but not identical finger prints.
423228
Only identical twins have similar fingerprints.\n\nOtherwise all of us have different fingerprints.
774709
Hi! I'm the mother of identical twins.  There's alot of misinformation out there.  Here's a few facts:\n\n1. Identical twins are from the same fertilized egg that splits so identical twins have identical DNA.  However, this does not mean that they will look exactly alike.  I can tell my identical twins apart easily and even strangers can look closely and notice subtle differences.\n\n2. Fraternal twins are from two seperate eggs that are fertilized at the same time.  They are basically just brothers/sisters who happen to be born at the same time.  You would expect them to look as similiar (or disimiliar) as siblings born years apart.\n\n3. Really, there's no reason why you should hesitate to ask them if they are fraternal or identical.  They'll probably appreciate that you actually know that there are different types of twins and that you didn't assume they were a certain type.\n\nHope this helps!