biological sex

plural biological sexes

1. countableuncountablesex, as in the biological factors that cause an individual member of a species that uses sexual reproduction to produce either male gametes (sperm or spermatozoa) or female gametes (ova).

   Biological sex [is] constituted by sex characteristics (chromosomes, gonads, internal genitalia, external genitalia, hormones and secondary sexual manifestations).

   1984, Rosemarie Tong, Women, Sex, and the Law, →ISBN, page 2

2. countableuncountableSynonym of birth sex (“sex assigned to a person when born”).

   1 more example

   Sex-appropriate masculine or feminine traits are not an innate psychological need but are derived from social expectations to act in ways which supposedly affirm or validate biological sex. Individuals are taught that it is not enough to know they are biologically male or female, but they must also act in ways which supposedly affirm their biological sex.

   1978, National Institute on Drug Abuse. Division of Scientific and Program Information, “Psychology of sex roles: Traditional and new views”, in Shattering Sex Role Stereotypes: Foundations for Growth

   Synonyms: birth sex