alternation of nuclear phases
Technical term in biology referring to the alternation between haploid and diploid phases in the life cycle of organisms.
Alternation of nuclear phases is seen in the life cycles of many plants and algae.
世代交代 refers to alternation of generations (multicellular stages), while 核相交代 specifically refers to the alternation of nuclear phases (haploid/diploid).
Compound of 核 (nucleus) + 相 (phase) + 交代 (alternation). A modern scientific term.