Yes, fraternal twins are formed when two eggs are fertilized by two separate sperm.
To understand this better, let's look at the different types of twins:
Types of Twins
There are two main types of twins: identical (monozygotic) and fraternal (dizygotic).
| Type of Twins | Number of Eggs | Number of Sperm | Genetic Similarity |
|---|---|---|---|
| Identical | One | One | Exactly the same |
| Fraternal | Two | Two | Genetically unique |
Identical Twins (Monozygotic)
Identical twins develop from one fertilized egg (ovum) that splits into two. Each half develops into a separate baby. Because they come from the same fertilized egg, they share nearly the same genetic information.
Fraternal Twins (Dizygotic)
Fraternal twins occur when two eggs (ova) are fertilized by two separate sperm. Each fertilized egg develops into a separate baby. Fraternal twins are genetically no more similar than any other siblings, although they shared the same womb. As the reference mentions: "To form fraternal or dizygotic twins, two eggs (ova) are fertilised by two sperm and produce two genetically unique children."
In summary, while identical twins result from one sperm fertilizing one egg, fraternal twins are indeed the result of two separate sperm fertilizing two separate eggs.
