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Pollination is the transfer of pollen from an anther of a plant to the stigma ... After entering an ovule through the micropyle, ... It is a type of sexual breeding ...
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes , resulting in offspring genetically different from either parent.
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: asexual and sexual. In asexual reproduction, an organism can reproduce without the involvement of another organism.
Plant species where normal mode of seed set is through a high degree of cross-pollination have characteristic reproductive features and population structure. Existence of self-sterility, [ 1 ] self-incompatibility, imperfect flowers, and mechanical obstructions make the plant dependent upon foreign pollen for normal seed set.
This is common in plants (see Sexual reproduction in plants) and certain protozoans. [4] [5] In plants, allogamy is used specifically to mean the use of pollen from one plant to fertilize the flower of another plant and usually synonymous with the term "cross-fertilization" or "cross-pollination" (outcrossing). [4]
Pollen itself is not the male gamete. [4] It is a gametophyte, something that could be considered an entire organism, which then produces the male gamete.Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell.
Self-pollination can occur with or without the aid of animals. When animal-mediated, sexual organs will be positioned closer spatially and temporally, inverse to the strategies of dichogamy and herkogamy. However, when self-pollination is self-induced by the flower, some unique mechanisms have evolved.
A far more rudimentary form of double fertilization occurs in the sexual reproduction of an order of gymnosperms commonly known as Gnetales. [3] Specifically, this event has been documented in both Ephedra and Gnetum, a subset of gnetophytes. [7] In Ephedra nevadensis, a single binucleate sperm cell is deposited into the egg cell. Following the ...