Overview

2. Overview HIGHER PLANTS LOWER PLANTS

3. Moving on • Recap Chapter 20-21 • Next evolutionary step • Remember  plants are moving to drier and drier environments • What are some adaptations?

4. Plants with Seeds“Spermopsida” Chapter 22 p.466

5. Benefits Abundant sunlight for photosynthesis Continuous free movement of gases(O2/CO2) Problems Scared of: drying out Finding food while water and nutrients only available soil How to get sunlight without a stem No water, reproduction might not be possible Life on Land

6. Adaptations of Seed Plants to Life on Land • Vascular tissues (Xylem, Phloem) • Therefore, developed roots, stems, leaves • Reproductive adaptations • free from water • Use cones, flowers, pollen, seeds** • **Evolved seeds – a new form of sexual reproduction (no longer using spores and water) • Smaller gametophyte

7. Roots, Stems • Roots • Absorb water and nutrients from soil • Anchor plants in the ground • Hold plants upright, prevent plant from falling over (strong wind and/or rain) • Stems • Hold leaves up to the sun • Provide plant rigidity

8. Leaves • Capture sun’s energy • Covered with a waxy coating of cuticle

9. Stomata (p.504) • Have adjustable openings called stomata that allows gas exchange but help conserve water

10. Vascular Tissue • Xylem (transports upward) • Carries water and minerals from roots to leaves/stem • Thick cell walls provides strength in woodyplants • Dead cells • Phloem (transports up and downward) • Carries products of photosynthesis • Cells are alive

11. Reproduction Free from Water • Requires alternation of generations • Dominant generation: diploid (sporophyte) • Gametophytes are small in size • Specialized reproductive structures: • Flowers and cones VERY IMPORTANT ADAPTATION

12. Pollination • Male gametophytes are contained in small structures called pollen grain • Sperms produced don’t swim but carried by wind, insects, birds, small animals, bats • Pollination: Process of carrying the pollen to the female gametophyte(check out the picture at the beginning of the chapter)

13. Show TED Pollen Video

14. Seed Dispersal – Drop and Scatter Black Locust Seeds Sweet Gum Black Walnut

15. Seed Dispersal – By Wind Dandelion Maple Sycamore Aster flower Aster seeds Milkweed

17. Seed Dispersal • By wind (dandelion) • Bright berries – seedseaten and pass thruand out animal • By animal Sharp barbs – • stick to animal and drop off later

18. Seeds • Structures that protect the zygote of seed plants • Zygote grows into an embryo • Found into the seed • Seed provides food for the embryo in the cotyledon • Embryo may remain dormant for aLONG time

19. Why Stay Dormant? • In case of extreme climate • Too cold • Too hot • Lack of water (drought)

20. Seed Coat • Seed coat surrounds and protects embryo and prevents the food from drying out

21. Protists • Fungi-like, animal-like, plant-like • Lifecycle • Fungi • 5 classes • Reproduce with spores, sexual vs asexual • Plant • Aglae, mosses, ferns, gymnosperm • Seeds • Life cycles

22. Review • What is pollination? • What are the 2 function of stomata? • What are the 2 main specialized reproductive structures that evolved? • What are pollen grains?

23. Big Idea Review: Reproductive Adaptations As plants evolve, 3 important reproductive adaptations allowed continued success and diversification of plants in the terrestrial (land) environment • reduction of gametophyte, • the presence of the seed, • the evolution of pollen