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Gymnosperms

Gymnosperms

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Gymnosperms

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  1. Gymnosperms EQ: How do I describe the characteristics of gymnosperms?

  2. EQ: How do I describe the characteristics of gymnosperms? Gymnosperms • A seed plant that produces naked seeds – not enclosed by any protective covering • Most have needlelike or scale like leaves • Most have deep growing root systems

  3. Types of Gymnosperms • Oldest type of seed plant – appeared on Earth 360 million years ago • Classified into four groups • Cycads • Ginkgo • Gnetophytes • Conifers EQ: How do I describe the characteristics of gymnosperms?

  4. Cycads • 175 million years ago the majority of plant on Earth were cycads • Grows only in tropical areas now • Looks like a palm tree with cones • Cone can grow to be as large as a football • Seeds used to make flour for flour tortillas EQ: How do I describe the characteristics of gymnosperms?

  5. Ginkgo • Extremely old plant • Only one species survives today • Chinese and Japanese cared for this species in their gardens • Used today to line city streets - very resilient to pollution from city traffic EQ: How do I describe the characteristics of gymnosperms?

  6. Gnetophytes • Least likely to see • Live in hot dry desserts of southern Africa and Western US as well as rain forests EQ: How do I describe the characteristics of gymnosperms?

  7. Conifers • Cone bearing plants • Largest and most diverse gymnosperms • Keep their needles year round EQ: How do I describe the characteristics of gymnosperms?

  8. EQ: How do I describe the characteristics of gymnosperms? Reproduction • Cones – reproductive structure for a gymnosperm • Most gymnosperms produce two types of cones

  9. Reproduction Male cones • smaller than female cones • produce pollen that later become sperm Female cones • Larger than male • Contain one ovule at the base of each scale • Ovule – structure that contains egg cell EQ: How do I describe the characteristics of gymnosperms?

  10. Pollination • Transfer of pollen from a male reproductive structure to a female reproductive structure • Wind often carries the pollen • Pollen collects in the sticky substance produced by each ovule • Scales of ovule close and trap pollen • Seed develops on scale EQ: How do I describe the characteristics of gymnosperms?

  11. Pollination • Female cones stay on tree until seed matures • Male cones fall off after they shed their pollen EQ: How do I describe the characteristics of gymnosperms?

  12. Seed Dispersal • As seed develops female cone increases in size • Cones with immature seeds point upward • Cones with mature seeds point downward EQ: How do I describe the characteristics of gymnosperms?

  13. EQ: How do I describe the characteristics of gymnosperms?

  14. Class Work and Homework • Fill In • What did I learn • Confused • Say • Read pages A 150 – A 155 • Questions 1-4, A 155 EQ: How do I describe the characteristics of gymnosperms?