Anisogamous is a term used to describe the sexual reproduction of different sized gametes in organisms. There are many synonyms that can be used to describe anisogamous reproduction, such as heterogamous, allogamous, and oogamous. Heterogamous refers to the production of two different types of gametes, while allogamous describes the fusion of gametes from different individuals. Oogamous specifically refers to the production of large female gametes (eggs) and small male gametes (sperm). These synonyms help to more precisely describe the process of sexual reproduction in different organisms, and are useful for categorizing and comparing different species.