response: I see, well that means that each of the twins is fertilized by a sperm cell.
original_response: In fraternal twins, each twin is fertilized by its own sperm cell
history: My cousin just gave birth to twin boys Neat, so she has two offspring from the same pregnancy now. Yeah, she had a daughter first but it's still an unexpected surprise. They're fraternal but I don't know what that means.
knowledge: In fraternal twins, each twin is fertilized by its own sperm cell.