Are the DNAs for twins exactly the same?

Question

We are told everyone is unique. Are the DNAs for twins exactly the same?

Answer 1

identical twins, formed when one fertilized egg splits, are the only people in the world with identical DNA. Fraternal twins, on the other hand, are formed when two different eggs are fertilized. Genetically speaking, fraternal twins are no closer than normal siblings, sharing only about 50% of their genes.
Although identical twins have the same genotype, or DNA, they have different phenotypes, meaning that the same DNA is expressed in different ways.Traits determined by phenotype, such as fingerprints and physical appearance, are the result of "the interaction of the individual's genes and the developmental environment in the uterus." Thus, a DNA test can't determine the difference between identical twins, while a simple fingerprint can.

Answer 2

If the twins are "Identical Twins", meaning that the mother ovulated and produced 1 egg and 1 sperm cell from the father fertilized that single egg. That egg then develops into a zygote which divides into 2 fetuses. In this case, the DNA will be the same. The same may be possible for triplets, etc.

If the twins are "Fraternal", meaning that the mother ovulated and produced 2 or more eggs (usually in one cycle, but not necessarily). Then, each egg is fertilized by a separate sperm cell, producing twins (or triplets, etc.). Having come from separate eggs and sperm, these twins will have different DNA.

And then, there is Chimerism. During pregnancy, the zygote (typically) absorbs an extra sperm cell or egg cell, which introduces different DNA into the unborn child. Less commonly, there may be 2 zygotes formed from 2 fertilized eggs merging into each other. In either case, the single child who is born grows up as a single, whole individual, but has different DNA in different parts of the body. A chimera may even have both male and female body parts (a hand may have male DNA and the arm may have female DNA, etc.). This can make court cases (paternity, crimes, etc.) very interesting if one of the parties involved is a chimera (picture a DNA sample being taken from the wrong part of a chimera's body).

Answer 3

The answer is Yes and No. It is according what kind of twins they are. Identical twins or Maternal twins are conceived by the splitting of one fertilized egg into two individual eggs. In that case the DNA would be exactly the same. Now, paternal twins come from two individual eggs being fertilized by two different sperms at the same time. Which the makes the DNA in those type of twins different.

Answer 4

Only identical twins have exactly the same DNA

Answer 5

If the twins are from the same embyro then yes they will have the same DNA structure, but twins from two different embryos will not. Cases where none identical twins would be if there's a boy and birl twin, which you would know for sure they will have different DNA

Answer 6

The DNA of identical or homozygous twins are exactly similar because they are derived by accidental splitting of 1 zygote.. But the DNA of fraternal twins are different.. They are just siblings born one after another. They derived from separate zygotes and enclosed by separate birth membrane. Fraternal twining results due to multiple ovulation of female..

Answer 7

Not exactly but if a DNA test for identical twins was done they could not tell them apart.

Answer 8

For identical twins yes, unless there were some mutations (not likely). But even identical twins can be a bit different - that is due to mitochondrial DNA, which can be different.

Answer 9

For identical twins, the DNA is exact. Yes.

Answer 10

Yes, if they are identical. But our personality is also the sum of our experiences: Someone brought up in even slightly varying environements will have a different personality. That's why you can often tell twins apart; they look a little different.