Base Definitions

This page establishes foundational biological terminology used throughout the site. All definitions are biological in nature and are intended to be descriptive, not normative.


Terminology

TermMeaning
FecundityBiological capability to reproduce
GametogenesisProduction of sex cells (gametes)
SpermatogenesisProduction of small gametes (sperm)
OogenesisProduction of large gametes (eggs / ova)
FertilityActual reproduction (e.g., number of offspring born)
InfertilityFailure to achieve pregnancy despite fecundity
IntersexCongenital variations in sex development affecting sex-linked traits

Sex classification in sexually reproducing species

In sexually reproducing species (including humans), biological sex is defined by the type of gametes an organism is developmentally organized to produce.

  • Male:
    An organism developmentally organized for the production of small gametes (sperm)

  • Female:
    An organism developmentally organized for the production of large gametes (eggs / ova)


Intersex

Intersex is an umbrella term describing a range of congenital variations in sex development. These variations may affect one or more sex-linked traits, including:

  • Chromosomes (e.g., XX, XY, variations or mosaics)
  • Gonadal development (e.g., testes, ovaries, or mixed / atypical gonads)
  • Hormone production or responsiveness
  • Internal or external reproductive anatomy

Intersex conditions represent deviations in typical sex development pathways but do not constitute an additional sex category based on gamete production.

Individuals with intersex traits are still biologically male or female depending on their underlying developmental organization, even when reproductive function is impaired or atypical.