1. 22-4 & Seed Plants

2. Seed Plants Divided into two groups:
Gymnosperms – have seeds directly on surfaces of cones
Angiosperms – have seeds within a layer of tissue that protects the seeds
Also called “flowering plants”

3. Seed Plants Why are they the most dominant plants on land?
Unlike bryophytes (mosses) and ferns, seed plants don’t require H2O to reproduce
As a result, seed plants can live just about anywhere, wet or dry!

4. Seed Plants
Adaptations that allow seed plants to reproduce without water include:
Protection of embryos in seeds
Seed-containing structures: cones (gymnosperms) and flowers (angiosperms)
Transfer of sperm by pollination

5. The seed
Seed – embryo of plant encased in a protective covering (seed coat) and surrounded by a food supply

6. Tough Seeds
Seeds can survive long periods of bitter cold, extreme heat and even drought by only continuing to grow when conditions are more ideal
example: Desert Paintbrush (Castilleja chromosa)

7. Pollination Pollen grain: entire male gametophyte (sperm)
Pollination: transfer of pollen from male sex structure to female sex structure
by water, wind, insects, or small animals

8. Gymnosperms – “naked seed”
Produce seeds that are exposed
Cone-bearing plants
Oldest surviving seed plants
Include conifers (ex. pine trees), cycads and ginkgoes

9. Angiosperms – “enclosed seed”
Flower and fruit production are evolutionary advantage
Flowers
Attract pollinators
Contain ovaries which surround/protect seeds
Ovaries develop into fruit
Fruit
Protects the seeds
Helps spread seeds (remember the “Seedy Side of Seeds”?)

10. The 2 Classes of Angiosperms
Monocots: embryo has one seed leaf (cotyledon)
Examples: corn, orchids and palms
Dicots: embryo has two seed leaves (cotyledons)
Examples: roses, tomatoes, and oaks
** They have many differences…

11. Monocot/Dicot Table
Use same piece of paper you used for the “Alternation of Generation” drawing
In 2 squares underneath the “Alt. of Gen.” drawing, you will draw figure on p.570 of “Biology” textbook
Include: all headings for rows and columns, all descriptions and color all drawings