THE GYMNOSPERMS ARE FOUR RELATED PHYLA of seed producing plants;their seeds, however, lack the protective,outer covering which surrounds the seeds of flowering plants .Typically , gymnosperms are woody , perennial shrubs or trees, with stems ,leaves,and roots and a well developed vascular(transport ) system.
The reproductive structures in most gymnosperms are cones;male cones produce micro-spores in which male gametes (sex cells)develop,female cones produce megaspores in which female gametes develop.Microspores are blown by the wind to female cones ,male and female gametes fuse during fertilization and a seed develops.
The four gymnosperm phyla are the conifers,(phylum coniferophyta), mostly tall trees;cycads(phylum cycadophyta), small palm like trees,;the ginkgo or maidenhair tree(phylum Gnetophyta), a diverse group of plants , mainly shrubs , but also including horizontally growing welwitschia.
The reproductive structures in most gymnosperms are cones;male cones produce micro-spores in which male gametes (sex cells)develop,female cones produce megaspores in which female gametes develop.Microspores are blown by the wind to female cones ,male and female gametes fuse during fertilization and a seed develops.
The four gymnosperm phyla are the conifers,(phylum coniferophyta), mostly tall trees;cycads(phylum cycadophyta), small palm like trees,;the ginkgo or maidenhair tree(phylum Gnetophyta), a diverse group of plants , mainly shrubs , but also including horizontally growing welwitschia.
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