Is the DNA of identical twins the same?

When a single zygote divides into two, identical twins are formed. Since they divide out of a single zygote, their DNA should be same...But it is not so. We observe some differences. Where does that difference come from?

1 Answer
Aug 1, 2016

Nope, the DNA of identical twins are not the same.


The DNA at the time of the division of the zygote is exactly the same, but gradually mutations occur and a variation in the DNA is created. As the two zygotes, develop separately, the variation of DNA on one of them, is not exactly the same as that of the other DNA. These variations happen to be very minute. Hence 'identical twins' aren't perfectly identical.