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A seed plant that produces “naked” seeds

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Presentation on theme: "A seed plant that produces “naked” seeds"— Presentation transcript:

1 A seed plant that produces “naked” seeds
Gymnosperms A seed plant that produces “naked” seeds

2 What are gymnosperms? Seed plants that produce seeds NOT enclosed in a protective fruit. Many have needle-like leaves Deep growing root systems Oldest type of seed plant-giant sequoias

3 4 groups of gymnosperms Cycads Conifers Ginkgoes Gnetophytes

4 Cycads Grow mainly in tropical areas Look like palm trees with cones

5 Conifers Cone-bearing plants Most are evergreens
Pine trees, junipers, sequoias Largest, most diverse groups

6 Ginkgoes Only one species lives today Grew millions of years ago
Can tolerate air pollution-so planted along city streets

7 Gnetophytes Live in hot deserts and tropical rain forest
Some are trees, others shrubs or vines

8 reproduction Most involves CONES-covered with scales
Most gymnosperms produce male and female cones Male cones produce pollen which contain cells that will become sperm cells. Female cones contain ovules which contain the egg cell

9 Pollination Transfer of pollen from the male reproductive structure to the female reproductive structure Usually carried by wind Collects on a sticky substance produced by the ovule

10 Fertilization After pollination, the ovule will close and seal in the pollen. The sperm cell fertilizes the egg cell The fertilized egg (zygote) develops into the embryo It can take up 2 years for the seed to mature

11 Germination Once the seeds mature, the scales open
Wind shakes the seeds out and carries them away If seeds land in favorable conditions, the seed will sprout--germinate

12 Useful products Paper Lumber Rayon fibers Cellophane wrap Turpentine
Rosin These are renewable resources!


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