[Solved] In implementation terms, an entity is existence-dependent if it has a mandatory primary key. Sexual Orientation: An inherent or immutable enduring emotional, romantic, or sexual attraction to other people, which constitutes part of one's identity. Genetic Influences: The impact of genes inherited from parents on an individual's traits, such as physical characteristics, behavior, and risk of diseases. Identical Twins: Twins that develop from a single fertilized egg, sharing the same genetic material and typically having very similar appearances. Erotic Novel: A genre of literature that focuses on sexual love and relationships, often with explicit content.