As an adjective I cannot think of a scenario where they are not synonymous with each other. There are just contexts where one would be more appropriate to use. For example 'his biological mother' sounds better than 'his biologic mother' though this isn't incorrect. When talking about companies you would normally say 'company X sells biologics' rather than 'company X sells biologicals' ('company X sells biological products' is better). In general, I would use 'biological' rather than 'biologic'. As a noun, the definition for 'biologic' is "another term for biological". As you can see, the differences are very subtle. I would use 'biological' if you ever get confused.

Hello Tanya, 'biological' is an adjective derived from the word biology, so we have biological washing powder. 'Biologic' is a noun to describe a genetically-engineered protein which is derived from human genes. Hope this helps Bob

"Biological" is an adjective e.g. biological mother. "biologic" is a noun. Technically, a medical preparation made or derived from living organisms.