Short answers, pulled from the story.
A person's biological parents are the persons from whom the individual inherits their genes. This definition creates a clear line between those who provide DNA and those who nurture a child without that genetic link.
Robert Trivers proposed his theory regarding evolutionary conflicts of interest between parent and offspring fitness in 1974. An offspring who hates their father is called a misopater, while one that hates their mother is a misomater.
Current techniques for paternity testing use polymerase chain reaction and restriction fragment length polymorphism. Genetic fingerprinting has all but taken over all the other forms of testing including ABO blood group typing and analysis of various other proteins and enzymes.
Children and adolescents with same-sex parents suffer no developmental disadvantages compared with those with two opposite-sex parents. Social science literature rejects the notion that there is an optimal gender mix of parents and states that family processes contribute to determining children's well-being rather than family structures per se.
Most countries have laws that provide that the parents of a minor child are the legal guardians. Some jurisdictions allow a parent to exercise authority without a formal court appointment, and that parent acting in that capacity is called the natural guardian of their child.