Isogamy

Sexual reproduction form involving gametes of the same size

Isogamy is a form of sexual reproduction that involves gametes of the same morphology, and is found in most unicellular eukaryotes. Because both gametes look alike, they generally cannot be classified as male or female. Instead, organisms undergoing isogamy are said to have different mating types, most commonly noted as "+" and "−" strains.

This keyword could refer to multiple things. Here are some suggestions: