Cenogenesis and Heterogenesis

Cenogenesis noun - Introduction during embryonic development of characters or structure not present in the earlier evolutionary history of the strain or species (such as the addition of the placenta in mammalian evolution).

Heterogenesis and cenogenesis are semantically related. In some cases you can use "Heterogenesis" instead a noun "Cenogenesis".

Heterogenesis noun - The alternation of two or more different forms in the life cycle of a plant or animal.

Cenogenesis and heterogenesis are semantically related. Sometimes you can replace term "Cenogenesis" with "Heterogenesis", this nouns are similar.