In bryophytes and pteridophytes, a gametophytic phase may begin without meiosis by apospory. This usually occurs when damage to a plant in the sporophytic phase leads directly to the growth of a plant that is in the gametophyte development stage but bears the chromosome complement that would normally be found in the sporophyte development stage (PO:0028002). A whole plant in the gametophyte development stage usually has half the chromosome complement of a plant in the sporophyte development stage, but not in the case of apospory. A whole plant in the gametophyte development stage may cease to exist by death at any point in its development. In seed plants, the whole plant in the gametophyte development stage may cease to exists through transformation, such as when pollen (PO:0025281) releases its pollen sperm cells (PO:0025121) or when a plant embryo (PO:0009009) begins to develop within an embryo sac (PO:0025074) of an angiosperm. During the gametophytic phase, a plant may produce gametes (PO:0025006) by mitosis.
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rdfs:comment
In bryophytes and pteridophytes, a gametophytic phase may begin without meiosis by apospory. This usually occurs when damage to a plant in the sporophytic phase leads directly to the growth of a plant that is in the gametophyte development stage but bears the chromosome complement that would normally be found in the sporophyte development stage (PO:0028002). A whole plant in the gametophyte development stage usually has half the chromosome complement of a plant in the sporophyte development stage, but not in the case of apospory. A whole plant in the gametophyte development stage may cease to exist by death at any point in its development. In seed plants, the whole plant in the gametophyte development stage may cease to exists through transformation, such as when pollen (PO:0025281) releases its pollen sperm cells (PO:0025121) or when a plant embryo (PO:0009009) begins to develop within an embryo sac (PO:0025074) of an angiosperm. During the gametophytic phase, a plant may produce gametes (PO:0025006) by mitosis.
rdfs:comment
In bryophytes and pteridophytes, a gametophytic phase may begin without meiosis by apospory. This usually occurs when damage to a plant in the sporophytic phase leads directly to the growth of a plant that is in the gametophyte development stage but bears the chromosome complement that would normally be found in the sporophyte development stage (PO:0028002). A whole plant in the gametophyte development stage usually has half the chromosome complement of a plant in the sporophyte development stage, but not in the case of apospory. A whole plant in the gametophyte development stage may cease to exist by death at any point in its development. In seed plants, the whole plant in the gametophyte development stage may cease to exists through transformation, such as when pollen (PO:0025281) releases its pollen sperm cells (PO:0025121) or when a plant embryo (PO:0009009) begins to develop within an embryo sac (PO:0025074) of an angiosperm. During the gametophytic phase, a plant may produce gametes (PO:0025006) by mitosis.
A whole plant development stage (PO:0007033) that has as primary participant a whole plant (PO:0000003) during the interval between meiosis or apospory and the time that the whole plant ceases to exist.
