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.
there are two types of twins-- fraternal and identical. Fraternal twins are genetically unique, and they usually have physical differences. Identical twins are identically identical, such as a clone, and have exact physcial characteristics, excluding weight and scars etc.
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
identical
Fraternal
Fraternal
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.
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.
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.
Identical twins are formed from a single egg that splits into two. Fraternal twins are formed from two separate eggs that are both separately fertilized. So identical twins have identical DNA, and fraternal twins do not.