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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.
The cone of Pinophyta (conifer clade) contains the reproductive structures. The woody cone is the female cone, which produces seeds . The male cone, which produces pollen , is usually ephemeral and much less conspicuous even at full maturity.
A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. Pollen tube elongation is an integral stage in the plant life cycle. Pollen tube elongation is an integral stage in the plant life cycle.
Pollen is released and carried by the wind to female cones. Pollen grains from living pinophyte species produce pollen tubes, much like those of angiosperms. The gymnosperm male gametophytes (pollen grains) are carried by wind to a female cone and are drawn into a tiny opening on the ovule called the micropyle. It is within the ovule that ...
The mature gametophyte of mosses develops into leafy shoots that produce sex organs that produce gametes. Eggs develop in archegonia and sperm in antheridia. [6] In some bryophyte groups such as many liverworts of the order Marchantiales, the gametes are produced on specialized structures called gametophores (or gametangiophores).
Pollen strobili of Pinophyta are similar to those of cycads (although much smaller) and Ginkgoes in that they are composed of microsporophylls with microsporangia on the abaxial surface. Seed cones of many conifers are compound strobili. The central stem produces bracts and in the axil of each bract is a cone scale. Morphologically the cone ...
A good predictor for when a plant will bloom and produce pollen is a calculation of the growing degree days. The color of pollen below indicates the color as it appears when the pollen arrives at the beehive. After arriving to the colony with a fresh load of pollen, the honey bee unloads its pollen from the pollen basket located on its hind legs.
Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid offspring in nature and in plant breeding work. In angiosperms, after the pollen grain (gametophyte) has landed on the stigma, it germinates and develops a pollen tube which grows down the style until it reaches an ovary.