who as the biological father and mother vs who as biological father and mother

Some examples from the web:

• I looked at the intake form, and he's listed as the biological father.
• She grabbed on to the idea of adoption because it was less painful than thinking of you as the biological father.
• Problems come up, arguments happen, and if Evan disagrees with any of your parenting choices, he would, as the biological father, have legal standing unless you specify otherwise now.
• And I knew that picking Owen would upset you, but having Owen as the biological father of my future child was the best choice.
• And you're an unfortunate little boy because you're more than likely to grow up without your biological father or your biological mother.
• It means one parent is biological mother and father.
• No, I didn't even tell them when I... I tried to find my biological mother and father before I started college.
• That the biological father was totally overwhelmed.
• Most human cells have two sets of 23 chromosomes, one inherited from the biological mother and the other from the biological father, giving a total of 46 chromosomes.
• You're the biological father of this child, kiddo.
• Looks like the biological father works at the boat company.
• He also appears to be the biological father of your son.
• Daddy Warbucks isn't the biological father.
• You are the biological father of 533 children.
• Well, he's the biological father.
• The biological father is a nonissue.
• He was the biological father of the nine-year-old daughter Hannah.
• I am the biological father of Hans Remminger.
• Even if I'm the biological father?
• No, he is the son of the biological father I haven't met.

Some examples from the web:

• And you're an unfortunate little boy because you're more than likely to grow up without your biological father or your biological mother.
• It means one parent is biological mother and father.
• No, I didn't even tell them when I... I tried to find my biological mother and father before I started college.
• I mean, my mother and my biological father.
• I am asking that you compel Westwood Fertility to contact Laura's biological father and inform him of her condition.
• I don't want to risk a defense attorney finding out that he's my biological father and using it against us in court.
• And then, upon asking him again, he later admitted that he did know Kevin Neyers was his biological father and that he had given him money.
• Both your father and mother died.
• I have father and mother too.
• Most human cells have two sets of 23 chromosomes, one inherited from the biological mother and the other from the biological father, giving a total of 46 chromosomes.
• Whose love estranged her own father and mother.
• Country of birth of father and mother
• Father and mother of us all.
• His father and mother are dead, he knows what is Communism.
• John's father and mother are coming to dinner.
• My father and mother said so.
• They are your father and mother.
• I'm very grateful to your father and mother.
• My father and mother ran a magic theater in St. Petersburg.
• I killed my father and mother today.