Coniferophyta Sexual Cycle -3
Microsporangia are also found in Cones.
Each Microsporophyll has two Microsporangia.
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 Microsporangiate Cone |
 Longitudinal section through a Microsporangiate Cone. These produce Pollen which constitutes the Microgametophyte |
 SEM of Pine Pollen |
 Pine pollen contains several cells and is the Microgametophyte. It has bladder-like Wings that make it buoyant in Air. |
 A Pollen Tube is produced upon Germination. Two NONflagellate Sperm are also produced. The follow the Pollen Tube to the Archergonium where Fertilization occurs. This restores the Sporophyte Generation. |
 The Embryo Grows into the Megagametophyte. The Integuments become the Seed Coat. |
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| The Embryo Has Cotyledons, a Shoot Apical Meristem, a Hypocotyl and a Root Apical Meristem. | |
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| The Root is the first Organ to emerge during Germination. The hypocotyl also elongates. The Cotyledons absorb nutrients from the Megagametophyte. |  |
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| The Megagametophyte eventually falls
away. The Epicotyl forms the main axis of the Sporophyte Stem |
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