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Listing 1 - 8 from 8 for male gametophyte

Fern Allies
... have lost their photosynthetic capacity and rely on the fungus to provide carbohydrate! The gametophyte bears antheridia and archegonia and motile sperm cells swim to the eggs to ... bears a microsporangium which by meoisis produces many microspores which in turn form male gametophytes and male gametes. In Selaginella, gametophytes develop within the actual spores, a phenomenon termed endospory ...
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The Evolution of Seeds
... the gametophyte can succeed. The gametophyte is the weak link in the life cycle. Lack of genetic variability: In many of these plants it is quite possible for male gametes produced by a gametophyte to fertilize eggs produced by the same gametophyte. In such cases, the only source of variation is ...
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Cycads
... shoot apex. Most other cycads, however, have both male and female cones (see right). Pollination integument micropyle megasporangium archegoium female gametophyte Cycad cones generate heat which may aid in ... microsporophylls always grouped into cones (megasporophylls also form cones except in Cycas) The gametophyte has been internalized (endospory) and reduced to a single prothallial cell in the ...
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Practical - Gymnosperms
... species remain. As for other gymnosperms the microsporphylls are grouped into male cones. The megasporophylls, on the other hand, are another matter. In ... . Have a look at the large cones of this species. The male cone is short-lived and the released pollen lodges in a ... pollen grain. It takes a further 2 years for the female gametophyte to develop, to produce eggs, for fertilization to occur and the ...
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The Pines
... Male reproductive organs The male cone or microstrobilus is simply an axis bearing microsporophylls, each with two pollen-filled microsporangia. Biodisc photomicrograph0 In the microspore the male gametophyte ... cell divides. The single megaspore in each ovule divides initiating the female gametophyte. Fresh immature female cone split longitudinally - pearl-like ovules conspicuous. (photo by James ...
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Caribbean Pine
... the sporophyte. The microspores or pollen grains dispersed from the male cones are windborne. Within each pollen grain is a minute male gametophyte. From pollination to seed maturity takes about 2 years. The ...
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Introduction to the Flowering Plants
... what male gamete will fuse with the egg Female gametophyte greatly reduced - (yellow region at right) to 8 nuclei. There is no archegonium. Biodisc photomicrograph Unique double fertilization - one male nucleus ... ovules. The gametophyte has been internalized (endospory) and reduced to 3 cells in the pollen grain and 8 cells within the ovule. Double fertilization with both male gametes in the ...
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Glossary
... gametophyte anisogametes motile gametes which differ slightly in size autotrophic nutrition synthesis of organic food molecules from inorganic compounds such as carbon dioxide benthic attached and submerged bisexual having both male ... describe plant species in which male and female sex organs are borne on separate individuals endospory a condition in which the gametophyte develops within the spore ...
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