1. Plant kingdom diversity Created by Kevin Bleier Milton High School Chapters 23 – 25

2. Plant groups  Bryophytes (seedless, non-vascular)  Seedless vascular plants  Gymnosperms  Angiosperms

3. Cladogram Nonvascular plants Green algae Seedless vascular plants GymnospermsAngiosperms Evolution of cuticle (and specialized cells / tissue)

4. Cuticle  Waxy covering that prevents water loss  Crucial for transition to land  Also clear … why?

5. Bryophytes  think moss

6. Bryophytes  Small  Found only in damp, moist areas on land  1) Leaves must touch water for photosynthesis  2) Sperm swims through water to reach egg

7. Bryophytes

8. Cladogram Bryophytes Green algae Seedless vascular plants Gymnosperms Angiosperms Evolution of cuticle (and specialized cells / tissue) Evolution of vascular tissue

9. Vascular tissue  Set of tubes that transport materials around plant  Allows plants to grow taller  Water travels up through xylem  Sugar travels throughout in phloem

10. Seedless vascular plants  Think ferns

11. Ferns live further on land  Mature plant survives fine with vascular tissue  But sperm must still swim to egg (needs film of water)

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

13. Pollen grains  Small and lightweight with sperm inside  Removes water requirement for fertilization

14. After pollen lands …  Builds pollen tube inside female structure to reach egg  Sperm still swims to egg inside plant

15. Full colonization of land  Vascular tissue (find water in soil) +  Reproduction through air (no need for water for sperm to swim)

16. Seeds  Tough coat protects newly fertilized zygote  Also contains supply of food to survive for a long time without growing (= dormancy)  Overall purpose – increases chances that offspring eventually grow

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

18. Gymnosperm pollen strategy  Release a lot, hope some pollinate  (Meanwhile, irritating everyone else)

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

20. Angiosperms  Think flowers (most diverse plant group)  If you eat it, it’s an angiosperm plant

21. Flowers  Attract animals to help carry pollen to the next flower  Color or scent attractors guide animals to obtain sugar from plant  Pollinators also brush by pollen, get on body  Overall purpose: reduces amount of pollen that plant has to make (not random wind travel)

22. Advertising in UV color

23. After fertilization, ovary becomes fruit

24. Fruits  Overall purpose: Help get seeds far away from parent plant (why?)  Many are sugary fruits – animals eat, seeds pooped out far away from parent (and with free fertilizer!)  Other fruits use wind (dandelion fruits), water (coconut fruits)

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

26. Asexual reproduction  Plants can also reproduce asexually  Many plant parts can regrow to make a whole new organism when separated (vegetative reproduction)

27.  Our assumption: angiosperms  Major organs: 1) Root 2) Stem 3) Leaf 4) Flowers Overview of plant organs

28.  Absorption of H 2 O and nutrients from soil  Thick root anchors plant, small hairs increase diffusion  Fungus threads also help absorption (symbiosis called _______________ ) Root organ mycorrhizae

29. Modified roots  Some species store sugar underground = potato

30.  Xylem moves H 2 O / minerals up to leaves  Phloem transports sugar to all cells Stem organ

31.  Often center of photosynthesis Leaf organ cuticle stoma (hole) guard cells cuticle vascular bundle (xylem + phloem)

32. Photosynthesis and leaves CO 2 +H2OH2O sunlight O2O2 +C 6 H 12 O 6 sunlight CO 2 H2OH2O C 6 H 12 O 6 O2O2

33.  Broad leaves – lots of photosynthesis, but lots of water loss as well  Where does this occur? Modified leaves tropical rainforests

34.  Cactus needles – modified leaves lower transpiration water loss – does photosynthesis in stem Modified leaves

35. Water movement up plant  Transpiration creates pull that moves water up a plant

36. Transpirational pull ____________ bonds form between H2O molecules hydrogen (leaf air space) (roots)

37. Transpirational pull As H 2 O transpires, it pulls other H 2 O molecules up Relies on cohesion between water molecules

38. Transpirational pull  Water moves up plant without energy use “solar-powered” “solar-powered”  Plants must still control transpiration rate

39. Moving sugar  Phloem right next to xylem  Sugar pumped into phloem from leaves, creates __________ solution compared to xylem  Water comes in by ___________ hypertonic osmosis

40. Plant reproduction  Recall purpose of seeds in gymnosperms and angiosperms  Recall purpose of fruits in angiosperms  Seed dormancy and triggers for germination (water, fire, etc)

41.  Meristem tissue – cells specializing in mitosis  Plant growth focused on growing taller first – why?  Tropisms – directed growth in response to a particular environmental stimulus Growth of plants

42. Plant tropisms  Phototropism – growth in response to light  Gravitropism – growth in response to gravity (roots “down”, shoots “up”)