Van is a type of Truck. Van is related to Small. Small is related to Doll. 
Biological is a synonym of Birth. Birth is related to Day. Day is related to Tree. Tree is a different concept from Specific. 
Truck <--IsA-- Van <--RelatedTo--> Small <--RelatedTo--> Doll 
Biological <--Synonym--> Birth <--RelatedTo--> Day <--RelatedTo--> Tree <--DistinctFrom--> Specific 