Fusion of two gametes which are dissimilar in size is termed as _______.

Fusion of two gametes which are of dissimilar size is called anisogamous. Fusion of  gametes of similar size is called isogamous. Oogamous is the fusion between one large, non - motile female gamete with a smaller, motile male gamete. Agamous does not involve the fusion of male and female gametes in reproduction.