After the chapter on Cells, some of you all have posed me the qn:
Are biological twins really identical in cells-wise?
well, here's the answer!
Although identical twins inherit the same DNA from their parents, the genome (DNA) is subject to changes as an individual grows and even influenced by its living environment.
Hence,even though identical twins are very similar as adults, the genome of each individual may be slightly different - due to mutations (remember our discussion on Cancer?) and the rearrangement of pieces of DNA - that have occurred uniquely in each twin, since the egg split.
A new term for you all to learn and impress your friends: Monozygotic twins
Monozygotic twins result when a single fertilised egg splits into two parts, each of which then forms a foetus in the womb. Therefore, identical twins are always of the same sex, and always contain identical DNA in their nuclei.
1 comment:
i have heard of twins that are of a different sex. one boy, one girl. how does this happen?!
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