either of two twins who developed from two separate fertilized eggs
- This study probed tone acquisition in a hearing-impaired child with early implantation, and compared him with his hearing-normal fraternal twin sister.
- Fraternal twins share one placenta.
- For fraternal twins, the concordance was 16%.
- Fowler and his colleagues thus turned to identical and fraternal twins.
- Derived from two separately fertilized eggs. Used especially of fraternal twins.
- They then compared the" concordance" of identical twins (in how many pairs both got or escaped cancer) with the concordance in fraternal twins.