The twins also usually share only one set of external genitalia.

Observing his son and daughter, Thad notes that twins share a unique bond.

Fraternal twins do not share any more genetic information than siblings born separately.

These twins usually share a heart, and may also share the liver or part of the digestive system.

These twins almost never share any vital organs, with the exception of the liver.

Throughout their lives the twins share an empathic bond, that enables them to each feel what is happening to the other, but not themselves.

Identical twins share the same genes and tend to be much more similar in language ability.

On average, two normal fraternal twins would share about half their genes.

Kendra retained the single kidney which the twins had shared.

Ben had his own room; the twins share one.