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Plant Diversity II: The Evolution of Seed Plants

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Presentation on theme: "Plant Diversity II: The Evolution of Seed Plants"— Presentation transcript:

1 Plant Diversity II: The Evolution of Seed Plants
Chapter 30

2 Learning Targets

3 Seeds and pollen grains are key adaptations for life on land

4 Seeds vs. Spores Spores Seeds No protection or support for embryo
Rely on environmental conditions for dispersal Short lifetime (no dormancy) Provide protection and support for embryo Dispersal via various means (fruits  animals) Dormancy allows a waiting period for ideal conditions

5 Five Derived Traits of Seed Plants
Reduced gametophytes Microscopic male and female gametophytes (n) are nourished and protected by the sporophyte (2n) Male gametophyte Female gametophyte Heterospory Microspore (gives rise to a male gametophyte) Megaspore (gives rise to a female gametophyte) Ovules Integument (2n) Megaspore (n) Ovule (gymnosperm) Megasporangium (2n) Figure 30.UN04 Summary figure, Concept 30.1 Pollen Pollen grains make water unnecessary for fertilization Seeds Seeds: survive better than unprotected spores, can be transported long distances Seed coat Food supply Embryo

6 Gymnosperms bear “naked” seeds, typically on cones

7 Gymnosperms Ex: Cycads, Ginkos, Gnetos, Conifers SEED!
Inside a seed is the female gametophyte Pollen is male gametophyte If sperm reaches ova, zygote forms Seeds help plants survive harsh conditions Gymnosperms have a naked seed (cones)


9 The reproductive adaptations of angiosperms include flowers and fruit

10 Angiosperms Ex: Very diverse plants (monocots, dicots)
Flower – helps plants reproduce Fruit – helps seed dispersal


12 Human welfare depends greatly on seed plants

13 Plant Uses and Benefits

14 Plant Uses and Benefits

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