Twins and identical twins

Twins and identical twins

• Fraternal (non identical) twins: They are created when two egg cells are fertilized, each egg by a different sperm so that two embryos are created. Fraternal twins can be of the same or opposite sex and they don't have to look the same. 

 

• Identical twins: They are created when one egg after being fertilized by one sperm, divides into two halves, usually within the first twelve days of mom's pregnancy. Those two halves are genetically identical. Identical twins have almost identical brain wave patterns and they are usually of the same sex. They also share the same DNA. Parents of identical twins say that they are not exactly the same, each twin has his or her own separate personality and many physical differences.

• Conjoined (siamese) twins: They are created exactly like identical twins, but during the split, the embryo doesn't separate completely to create two separate babies and the twins develop attached to one another.

 

The differences between fraternal twins and identical twins are that the identical twins ar almost identical and  fraternal twins aren't identical.

BY: Elsa Baixeras 6ºA