1. Units 22 and 23
SEED PLANTS

2. Nonseed Plant Life Cycle Seed Plant Life Cycle
Life Llife Cylce of
Nonseed Plant Life Cycle
Flagellated sperm must swim
Seed Plant Life Cycle
Pollination

3. Highlights in the History of Seed Plants
Late in the Devonian, some plants developed secondary growth: thickened woody stems of xylem

4. How Did Seed Plants Become Today’s Dominant Vegetation?
Surviving seed plants fell
into two groups:
Gymnosperms: pines and cycads
Angiosperms: flowering plants

5. Gymnosperms
Any vascular plant that reproduces by means of an exposed seed, or ovule
“Naked Seed”

6. Gymnosperm

7. Four major phyla of living gymnosperms:
(a)Cycads: Cycadophyta
Sago palm
Cone-bearing
palm like
tropical
dinosaur food ?

8. Gymnosperms
b)Ginkgos: Ginkgophyta
One living species, Ginkgo biloba
Seed coat stinks
Polluted areas
1945 atom bomb
The ginkgo is a living fossil, recognizably similar to fossils dating back 270 million years.

9. Ephedra *ephedrine Gymnosperms (c) Gnetophytes: Gnetophyta
Shrubs , trees, or vines
the group is a small one, consisting of three families, each with one genus, totaling 68 species
Ephedra *ephedrine

10. (D)Conifers Coniferophyta
Gymnosperms
(D)Conifers Coniferophyta
largest group of gymnosperms
pines, hemlock, spruce, evergreen conifers
leaves stay all season
sap ----antifreeze
first real development of wood
dead transport tissue

11. Gymnosperms
Softwood

12. Flowering plants are the dominant plant today
Angiosperms
Flowering plants are the dominant plant today

13. Angiosperms
They are the largest group of plants with about 90% of all plant species. .

14. A
Angiosperm
Protected Seeds

15. FLOWERS are the exclusive reproductive organ of angiosperms
“The earth laughs in flowers” Ralph Waldo Emerson

16. What Features Distinguish the Angiosperms?
Angiosperm: “enclosed seed”

17. Angiosperms Female reproductive structures Carpel
Stamen
Anther
Filament
bear microsporangia - sperm ( pollen)
Female reproductive structures
Carpel
Stigma, style, and ovary
bear megasporangia -egg
(one or more carpel make up a pistil)

18. Angiosperm
Pollen
B - Dandelion (Taraxacum sp.) Transmission electron microscopy
F Pine (Pinus sylvestis): Light microscopy
G Mixed pollen grains (bright field light microscopy, stained)

19. Anigosperms
Flowers may have contributed to the enormous success of angiosperms.
The flowers attract a pollinators which carry pollen to other individuals of the same species

20. Angiosperms Attracted to sweet smells Need landing platform Can hover
Need bigger landing platform
Like bright colors
Attracted to strong smells
Can hover; nocturnal
Can hover
Prefer red color

21. Angiosperms Double fertilization
Sperm A leads to the formation of a Seed
Sperm B leads to the formation of an endosperm
(a nutritive tissue within the seed that feeds the developing plant embryo)

22. Flowering plants are divided into two groups

23. Cotyledon?
Embryonic seed
is the first leaf or set of leaves that sprout from a seed
Store nutrients for the embryo

24. A cotyledon – “seed leaf”
contain nutrients for growth during embryonic development
upon germination, the cotyledon may become the embryonic first leaves of a seedling.

25. Dry fruit vs. Fleshy fruit