Gymnosperms- Chapter 18

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Gymnosperms- Chapter 18
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Naked versus Enclosed Seed Plants

• Gymnosperms
• Gymno- gr. naked.
• Sperma- gr. seed.
• Angiosperms
• Angeion- gr. vessel.
• Sperma- gr. seed.

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Extant Gymnosperms

• Match the common name on the right to the phylum
  on the left.
• 1) Cycadophyta a. ginkgo
• 2) Ginkgophyta b. conifers
• 3) Coniferophyta c. cycads
• 4) Gnetophyta d. gnetophytes

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Cycadophyta

• Cycas- gr. palm.
• Tracheids, but no vessel elements.
• Sperm present, multiflagellated.
• Palmlike leaves.
• Pollen tube does not fuse with the egg cell.
• Ovulate (megasporangiate) microsporangiate
  cones simple on separate plants.
• 11 genera 140 species.
• Examples- Cycas Zamia.

Zamia
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Cycas
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Ginkgophyta

• Yin- ch. silver, hing- ch. apricot.
• Tracheids, but no vessel elements.
• Sperm present, multiflagellated.
• Fan-shaped leaves.
• Pollen tube does not fuse with the egg cell.
• Ovulate microsporangiate cones on separate
  plants fleshy-coated seeds.
• 1 genus 1 species.
• Examples- Gingko biloba maidenhair tree.

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Coniferophyta

• Con- gr. cone, fer- L. bear.
• Tracheids, but no vessel elements.
• Sperm not motile.
• Needlelike or scalelike leaves.
• Pollen tube fuses with egg cell.
• Ovulate microsporangiate cones on same plant
  ovulate cones compound.
• 70 genera 630 species.
• Examples- Pinus, Picea, Juniperus, Abies,
  Cupressus.

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True or False. These winglike structures
are female pollen grains.-------------------------
-gt
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Pinus- pine (Pinaceae).
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Metasequoia- Dawn redwood.
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Wollemia nobilis- Wollemi pine.
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Gnetophyta

• Gneto- Malay gnenom.
• Tracheids and vessel elements.
• Sperm not motile.
• Scalelike, leaflike, broad and leathery leaves.
• Pollen tube fuses with egg cell.
• Ovulate microsporangiate cones compound
  mostly borne on separate plants.
• 3 genera 70 species.
• Examples- Gnetum, Ephedra, Welwitschia.

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Gnetum
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Ephedra
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Welwitschia