alternation of generations
al·ter·na·tion of generations
noun \ˌȯl-tər-ˈnā-shən also ˌal-\Definition of ALTERNATION OF GENERATIONS
: the occurrence of two or more forms differently produced in the life cycle of a plant or animal usually involving the regular alternation of a sexual with an asexual generation but not infrequently consisting of alternation of a dioecious generation with one or more parthenogenetic generations
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