Definition

Noun: The genetically determined physical features directly involved in biological reproduction. These are the fundamental anatomical structures present at birth that distinguish male and female sexes, primarily the reproductive organs and genitals.

Usage

This term is used in biological, medical, and anthropological contexts to describe the innate, physical basis of biological sex. It contrasts with secondary sexual characteristics, which develop later (e.g., during puberty) and are not directly part of the reproductive system.

Examples

• In human biology, the primary sexual characteristics include the ovaries and uterus in females and the testes and penis in males.
• The development of primary sexual characteristics is determined by chromosomes during fetal development.
• When classifying an organism's sex, scientists first examine its primary sexual characteristics.

Advanced Usage

• The phrase is often used in the plural form "primary sexual characteristics".
• In discussions of disorders of sex development (DSD), the atypical development of primary sexual characteristics is a key diagnostic factor.
• The term establishes a foundational distinction in sexology between the reproductive anatomy (primary) and other sex-linked traits like body hair or voice pitch (secondary).

Variants and Related Words

• Primary sex characteristic: A less common but synonymous variant.
• Secondary sexual characteristic (noun): Physical traits that emerge during puberty (e.g., breast development, facial hair) which are influenced by but not directly part of the reproductive organs.
• Genitalia (noun): A more general term for the external and internal reproductive organs.

Synonyms

• Reproductive organs
• Genitals
• Sex organs

Related Phrases/Idioms

No common idioms or phrasal verbs are directly associated with this specific technical term.

Noun

1. the genetically determined sex characteristics bound up with reproduction (genitals and organs of reproduction)