What's the difference between identical and fraternal twins?

Identical twins are formed from a fertilized egg which splits very early in its embryonic development-giving rise to two embryos with identical genes. These babies will be monozygous, and may share one placenta (monochorionic). Fraternal twins (dizygous) are from two different eggs that fertilize separately, and implant in the uterus at the same or a similar time, but are genetically distinct.

Fraternal Twins
Fraternal (dizygotic) twins are the result of two separate eggs being fertilized by two sperms at the same time, so that two embryos implant and develop with two placentas. The twins may look different and be different sexes.
)

Identical Twins
If an egg is fertilized by one sperm and then splits into two, the two embryos that are produced are always the same sex and are identical because they contain the same genetic material; these twins are known as monozygotic.
)
Wednesday, 24 April, 2024 Add To Favorites | Make Us Your Start Page
Search 

Login  
Username: 
  Password: 
  

Forgotten
Password?

  Site Menu

Home
Ask A Question
Search
Register
Glossary
About Us
Contact Us

Win a signed copy
of the book. Register to be entered into our weekly prize draw!

  Our Sponsors





 
Home | Ask A Question | Search | Register | Glossary | About Us | Contact Us
© 2006 Pregnancy Questions & Answers