You know that when two children are born at the same time to the same
mother they are called twins. Most twins develop when two different ova
are fertilised by two different sperm.
These are called fraternal twins and they don´t look exactly like each
other. One twin can be thinner or taller or have a different colour hair
to the other twin.
However, some twins look exactly the same. These are called identical
twins. Identical twins develop when one zygote separates into two.
These two zygotes have the same genetic information so they develop
into identical embryos, and later into very similar children.
.Open a fact file and give a definition for twins using your laptop.
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