identical twins are from the same egg cell that split, but ferternal twins are from 2 entirely different fertilized egg cells. Thus identical look the same and ferternal can look entirely different.
Identical twins come from one egg and one sperm. Fraternal twins come from two eggs and two sperm.
how does the genetic makeup of a fraternal and identical differ
The girl and boy twins are fraternal, meaning they are not identical.
(Person that asked the question)-Once twins are born, and old enough to determine whether they are identical or fraternal, how do you know if they are identical, or just fraternal twins that look identical? I was just curious.
identical
Fraternal
Fraternal
The words identical and fraternal are the opposites. These opposites can be compared to puppies and kittens or black and white for example.
Identical and fraternal twins typically share many similar characteristics
There is no precise percentage of fraternal or identical twins but it is estimated that 2/3 of all twins are fraternal where as 1/3 of twins are identical.
If two (or more) eggs are fertilised and develop together you will get fraternal twins. Identical twins are the result of a single fertilised egg dividing into two embryos.
Quads can be identical, fraternal, or a pair of identical twins. Identical quads are rare- that would require 1 egg divide into 2, and then divide again into two. Most quads are fraternal.