Meiosis occurs only in the process of gametogenesis, i.e., when the gametes, or sex cells (ovum and sperm), are being formed. , process of nuclear division in a living cell by which the number of chromosomes is reduced to half the original number. In multicellular plants the sporophyte generation produces (by meiosis meiosis Among the fungi some spores are thin-walled and germinate quickly others are thick-walled resistant types. Yeasts, for instance, reproduce by forming spores as well as by budding. , process of nuclear division in a living cell by which the carriers of hereditary information, or the chromosomes, are exactly replicated and the two copies distributed to identical daughter nuclei. Many unicellular plants and animals reproduce both by the formation of spores and by simple cell division ( mitosis mitosis The term reproduction may refer to this power of self-duplication of a single cell or a multicellular animal or plant organism. Upon germination, spores that were generated asexually may produce cells or multicellular forms that can engage in sexual reproduction reproduction,Ĭapacity of all living systems to give rise to new systems similar to themselves. A spore is typically a cell surrounded by a cell wall in resistant spores and in the resting stage of reproductive spores this wall becomes tough and waterproof, permitting the cell to survive unfavorable circumstances such as extremes of temperature and moisture. Click the link for more information. produced by many unicellular plants and animals and by all plants that undergo an alternation of generations. There are many unicellular organisms, e.g.
The cell is the smallest unit in the living organism that is capable of integrating the essential life processes. In biology, the unit of structure and function of which all plants and animals are composed.
Spore, term applied both to a resistant or resting stage occurring among various unicellular organisms (especially bacteria) and to an asexual reproductive cell cell,
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