He's not your biological father?

It was time to accept that they would never have biological children.

In the Origin of Species, and in his other numerous and important contributions to the solution of the problem of biological evolution, Darwin confined himself to the discussion of the causes which have brought about the present condition of living matter, assuming such matter to have once come into existence.

The town hall, Athenaeum and museum are noteworthy buildings, the last having a fine biological collection.

Alex was uneasy because he and his biological father had never seen eye to eye.