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1. the process of reproduction.
2. a class composed of all individuals removed by the same number of successive ancestors from a common predecessor, or occupying positions on the same level in a genealogical (pedigree) chart.
alternate generation reproduction by alternate asexual and sexual means in an animal or plant species.
asexual generation (direct generation) production of a new organism not originating from union of gametes.
first filial generation the first-generation offspring of two parents; symbol F1.
parental generation the generation with which a particular genetic study is begun; symbol P1.
second filial generation all of the offspring produced by two individuals of the first filial generation; symbol F2.
sexual generation production of a new organism from the cell formed by the union of a male gamete (spermatozoon) and a female gamete (oocyte).
spontaneous generation the discredited concept of continuous generation of living organisms from nonliving matter.