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In Gymnosperms,what is sporophylls,strobili and cones?
Living gymnosperms are a diverse group of plants, most of which bear their sporangia in large, prominent strobili or cones. These strobili are similar to those of lycopsids and horsetails. Strobili consist of a shortened stem with several modified leaves (sporophylls) that bear sporangia. Like all seed plants, gymnosperms are heterosporous. The sporangia that generate the male microspores and female megaspores are usually borne on separate cones. Male cones (staminate cones) are typically much smaller than female cones (ovulate cones). Sporophylls that bear microsporangia are called microsporophylls. Sporophylls that bear macrosporangia are called macrosporophylls. The pine life cycle is typical of gymnosperms.

Gymnosperms produce pollen and eggs in structures called cones. Pollen cones have two micro sporangia at the base of each sporophyll, or scale.
 The gymnosperms are heterosporous; they produce haploid micro spores and mega spores. The two kinds of spores are produced within sporangia that are borne on sporophylls which are arranged spirally along an axis to form lax or compact strobili or cones.

 The strobili bearing microsporophylls and microsporangia are called microsporangiate or male strobili. The microspores develop into a male gametophytic generation which is highly reduced and is confined to only a limited number of cells. This reduced gametophyte is called a pollen grain. The development of pollen grains take place within the microsporangia.

 The cones bearing megasporophylls with ovules or megasporangia are called macrosporangiate or female strobili. The male or female cones or strobili may be borne on the same tree (Pinus) or on different trees (Cycas).


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