Diversity Part 2: Plants

1. Diversity Part 2: Plants Chapter 23 Introduction to Plants

2. Characteristics of Plants • Autotrophs • Multicellular • Eukaryotes • Cell Wall is made out of Cellulose

3. Plant Groups • Bryophytes-Mosses (Seedless, Non-Vascular) • Seedless vascular plants- Ferns • Gymnosperms- Evergreens (Pine Trees) • Angiosperms-Flowering plants

4. Photosynthesis • Chemical Equation: • CO2 + H2O  C6H12O6 + O2 • Word Equation: • Carbon Dioxide + Water  Glucose + Oxygen Sunlight Sunlight

5. Common Ancestor • The common ancestor of ALL plants is thought to be Green Algae • In the early evolution of plants, they made the transition from aquatic to land environments

6. Importance of Mycorrhizae • Mycorrhizae is a mutualistic relationship between plants and fungi to help a plant absorb water from the soil. • This relationship helped plants transition to land.

7. Cuticle • Almost all plants have a cuticle covering their leaves and stems to prevent water loss • The cuticle is waxy (lots of lipids) and holds water in • The cuticle is also clear to let sunlight in for photosynthesis

9. Alternation of Generations • An alternation between two distinct forms or generations that reproduce differently • One generation is haploid and reproduces sexually • The other generation is diploid and reproduces asexually

10. Alternation of Generations By definition, all plants alternate generations Gametophyte n=haploid Sporophyte 2n=diploid

11. Alternation of Generations Gametophyte and Sporophyte Notice that the more advanced plants have a dominant Sporophyte and the less advanced plants have a more dominant Gametophyte

12. Alternation of Generations Multicellular diploid organism(2n) sporophyte mitosis meiosis Unicellular diploid zygote(2n) Unicellular haploid cells(n) (spores) fertilization Unicellularhaploid gametes(n) mitosis Multicellularhaploid organism(n) gametophyte mitosis

13. Cladogram Gymnosperms Angiosperms Seedless vascular plants Bryophytes Evolution of specialized cells / tissue Evolution of cuticle Green algae

14. Non-Vascular Plants • Bryophytes • Example: Moss

16. Bryophytes • They are small and low to the ground because they do not have vascular tissue • Found only in damp, moist areas on land • 1) Leaves must absorb water for photosynthesis • 2) Sperm swims through water to reach egg in gametophyte

17. Bryophytes sporophyte gametophyte

18. Moss Life Cycle Moss Life Cycle

19. Cladogram Gymnosperms Angiosperms Seedless vascular plants Bryophytes Evolution of vascular tissue Evolution of specialized cells / tissue Evolution of cuticle Green algae

20. Seedless Vascular Plants • Example: Ferns

22. Key Adaptation over Nonvascular Plants • Vascular Tissue • Set of tubes that transport materials around plant • Allows plants to grow taller • Water travels up through Xylem • Sugar/Food travels throughout in Phloem

24. Ferns Live Further On Land • Still must live in moist areas • Sporophyte grows successfully with vascular tissue • But sperm must still swim to egg in tiny gametophyte

25. Fern Sporophyte

26. Fern Gametophyte

27. Fern Life Cycle Fern Life Cycle

28. Cladogram Gymnosperms Angiosperms Seedless vascular plants Evolution of pollen grains / seeds Bryophytes Evolution of vascular tissue Evolution of specialized cells / tissue Evolution of cuticle Green algae

29. Seed Plants • Gymnosperms/Angiosperms • Example: Pine Trees or Flowers

30. Gymnosperms • Examples: Spruce Tree, Fir Tree, Pine Tree

31. Gymnosperms • Think cones (any conifer like pine trees) female ovary male pollen cone

32. Pine treeGymnosperms tiny gametophyte inside cone sporophyte Sporophyte Dominates

33. Gymnosperm Pollen Strategy • Release a lot, hope some pollinate • (Meanwhile, irritating everyone else) • Pollen is the male sperm in Gymnosperms and Angiosperms

34. Key Adaptations Over Seedless Plants • Seeds • Pollen Grains

35. Seeds • Tough coat protects newly fertilized embryo • Also contains supply of food (endosperm) to survive during dormancy period • A seed in a gymnosperm is inside the cone

37. Seed Dispersal Plants try to disperse offspring far away so they have a higher chance of survival. Dispersal of seeds prevents competition for water, nutrients, light, and living space.

39. Seed Dispersal • Dispersal by wind – wing-like structures, parachute-like structures

40. Seed Dispersal • Dispersal by animals – fruits have hooks that cling on animals fur, other fruits provide food for animals

41. Seed Dispersal • Seeds dispersal is completed by birds, small animals, wind, and water • The tough, fibrous outer covering of a coconut provides protection as well as a floatation device

42. Pollen Grain • Hard covering around sperm, light weight allows travel by wind • Removes water requirement for fertilization

43. Sperm Still Swims • At the very end when pollen lands on another plant of the same species • Pollen tube connects to ovary, sperm swim to egg

44. Cladogram Gymnosperms Angiosperms Evolution of flowers / fruits Seedless vascular plants Evolution of pollen grains / seeds Bryophytes Evolution of vascular tissue Evolution of specialized cells / tissue Evolution of cuticle Green algae

45. Angiosperms • Think flowers • Most diverse plant group • Most Dominant Plant group on the planet

46. Key Adaptation Over Gymnosperms • Flowers • Adapted for pollination by animals • Attract animals to help carry pollen to the next flower • Color or scent attractors guide animals to obtain sugar from plant • Some angiosperms still wind pollinate (grass)

48. Advertising in UV color

49. Angiosperms are Divided intoMonocots and Dicots • Monocots include: grasses, corn, rice, oats, wheat, orchids, lilies and palms • Dicots include: shrubs, trees (except conifers) wild flowers and some garden flowers

50. Monocots