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2 kinds of cones. Conifers. Male vs. Female Cones. Male Pollen cones. Female Seed cones immature. Male. Female immature. Mature Immature. “ Naked” and “Covered”. Reproduction. Scales Male cones produce male gametophytes called pollen grain
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2 kinds of cones Conifers
Male vs. Female Cones Male Pollen cones Female Seed cones immature
Male Female immature
Reproduction • Scales • Male cones produce male gametophytes called pollen grain • Female cones (seed cone) produce female gametophytes called ovules(eggs) • Embryo – same idea as zygote (egg+sperm)
Conifer Reproduction In this example we are using a pine cone seed coat Egg (n) Female gametophyte (n) Unfertilized ovule
Unfertilized ovule
Conifer Reproduction Fertilization initiates the transformation of the ovule into a seed Female gametophyte (n) Discharged sperm nucleus (n) Micropyle Male gametophyte (pollen grain) (n)
Conifer Reproduction Compared to a single-celled spore, a seed is much more resistant and complex Seed coat Food supply Embryo (2n) Inside the seed (new sporophyte)
Rise to the Angiosperms Seed plants appeared ~360 mya with the rise of the Gymnosperms Flowering plants (Angiosperms) – the other surviving lineage – appeared ~200 million years later