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
30.1

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
30.2

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
29.3

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

12. Human welfare depends greatly on seed plants
30.4

13. Plant Uses and Benefits

14. Plant Uses and Benefits