heterogamy

Etymology
From.

Noun

 * 1)  The state of conjugating gametes that are different in size, structure and function.
 * 2)  Marriage or similar union between people of different sexes, or social strata, such as races.
 * 1)  Marriage or similar union between people of different sexes, or social strata, such as races.
 * 1)  Marriage or similar union between people of different sexes, or social strata, such as races.