What is the difference between identical and fraternal twins explain

Hold on tight! When you have identical twins, the name explains it all. They will be identical in every way when they are born, from their gender to their eye color and hair color. Identical twins are also referred to as monozygotic twins. They are the result of one fertilized egg that divides into two during the earliest stage of pregnancy. When you have fraternal twins, two separate eggs have become fertilized at the same time.

These twins are also referred to as dizygotic. Fraternal twins will not look identical and can have different genders. Essentially they are as similar as two siblings. Identical twins may share an amniotic sac and a placenta, or they may just share one of the two, or neither! They share half of their genes just like any other siblings. In contrast, twins that result from the fertilization of a single egg that then splits in two are called monozygotic, or identical, twins.

Identical twins share all of their genes and are always the same sex. Fraternal twins are also called dizygotic twins. Girl-boy twins occur when one X egg is fertilized with an X sperm, and a Y sperm fertilizes the other X egg.

Sometimes health care professionals identify same-sex twins as fraternal or identical based on ultrasound findings or by examining the membranes at the time of delivery. Occasionally a family is told that their twins are fraternal based on placenta findings, when they are in fact identical. Other times, a family may see the minor differences in identical twins and declare the twins fraternal based on these differences in appearance.

There are a few commercial laboratories that, for a fee, will send families DNA collection kits to determine if the twins are identical or fraternal. Identical twins have the same DNA; however, they may not look exactly identical to one another because of environmental factors such as womb position and life experiences after being born.

All twins, whether fraternal or identical, are truly 2 separate, unique individuals. You may be trying to access this site from a secured browser on the server. Please enable scripts and reload this page. Turn on more accessible mode. Turn off more accessible mode. Skip Ribbon Commands. Skip to main content.