Biology is related to Subject. Subject is a synonym of Action. Action is related to Vote. Vote is related to Election. 
Violent is related to Crush. Crush is related to Romantic. 
Biology <--RelatedTo--> Subject <--Synonym--> Action <--RelatedTo--> Vote <--RelatedTo--> Election 
Violent <--RelatedTo--> Crush <--RelatedTo--> Romantic 