1. PLANT Evolution Structural Adaptations Vascular system – roots and shoots (tracheophytes) Mycorrhizae – fungal associations Stomata and cuticle Lignin – hardens cell walls – preventing water loss Vascular tissues – xylem and phloem

2. Stomata

3. Reproductive Adaptations Must keep gametes from drying out. Gametangia – jacket surrounding moist chamber where gametes can develop Sperm encased in pollen and egg in ovule

4. Origin from Algae Charophytes – closest to plants in molecular studies Natural selection favored those who could survive when not submerged in water

5. Origin of Plants

6. Plant Evolution 4 major periods in plant evolution 1. Bryophytes – mosses – gametangia – little or no vascular tissue 2. Ferns (Pterophyta) – seedless, vascular plants 3. Gymnosperms (Coniferophyta) – the first seed plants 4. Angiosperms (anthophyta) – emergence of the flowering plants – complex reproductive organs

7. Bryophytes Mosses Cuticle and gametangium Sperm are flagellated – must swim to reach eggs No lignin, no vascular system Seedless 2 generations – gametophyte (n) and sporophyte (2n) Alternation of Generations

8. Bryophytes

9. Moss Life Cycle

10. Ferns Have vascular tissue Sperm must swim through water to reach eggs Seedless Inhabit tropical areas

11. Ferns

12. Gymnosperms At the end of the Carboniferous period – climate became cold and dry. Provided opportunity for seed plants Conifers – pine, spruce, firs, redwoods Nearly all conifers are evergreen Thick cuticle – stomata in pits

13. Life Cycle of Conifer Sporophyte generation and gametophyte generation. Use pollen grains to transport sperm Seeds can remain dormant for years Fire, rain, and animals can crack seeds and cause germination.

15. Angiosperms 2 types of flowering plants – Monocots and Dicots Undergo double fertilization Pollen deposits two sperm nuclei in the female gametophyte One sperm fertilizes an egg- produces a zygote and develops into an embryo The second fertilizes another female gametophyte cell which develops into an endosperm (nutrient storing tissue) A mature ovule is a seed, a mature ovary is the fruit

17. Monocots and Dicots

18. Monocots vs. Dicots Monocots One cotyledon (seed leaves) Flower parts in multiples of 3 Parallel leaf veins Ex. Corn,lily Dicots 2 cotyledons Flower parts in multiples of five Netlike leaf veins Primrose, maple