1. Plant kingdom diversity
Chapters 20-22
Created by Kevin Bleier
Milton High School

2. Characteristics of Plants
Autotrophs
Multicellular
Eukaryotes
Plant cell walls made of cellulose

3. 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

4. Water is short on land, so relationships like mycorrhizae are important

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

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

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

8. Bryophytes
think moss

10. 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

11. Bryophytes

12. Seedless vascular plants
Cladogram
Gymnosperms
Angiosperms
Seedless vascular plants
Non-vascular plants
Evolution of vascular tissue
Evolution of cuticle (and specialized cells / tissue)
Green algae

13. Seedless vascular plants
Think ferns

15. 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

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

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

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

19. Gymnosperms
Examples: Spruce Tree, Fir Tree, Pine Tree

20. Key Adaptations Over Seedless Plants
Seeds
Pollen Grains

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

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

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

24. 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

25. 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.

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

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

28. 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

29. Gymnosperm cones

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

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

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

33. Flowers (key adaptation over gymnosperms)
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)

35. Pollinators

36. Advertising in UV color

37. After fertilization, ovary becomes fruit

38. 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)

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

40. Asexual reproduction Plants can also reproduce asexually
Vegetative reproduction is faster than sexual reproduction.
Vegetative reproduction is where many plant parts can regrow to make a whole new organism when separated.
Examples: Ivy or Potato

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

42. Root organ Absorption of H2O and nutrients from soil
Thick root anchors plant, small hairs increase diffusion
Fungus threads also help absorption (symbiosis called _______________ )
mycorrhizae

43. Modified roots
Some species store sugar underground = potato

44. Stem organ Xylem moves H2O / minerals up to leaves
Phloem transports sugar to all cells

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

46. Photosynthesis and leaves
sunlight
C6H12O6
H2O
CO2 O2
sunlight
CO2 +
H2O
C6H12O6 + O2

47. stoma Stomata are tiny holes in the cuticle. can open and close
allow air to move in and out
stoma
Let in carbon dioxide and let out oxygen and water
Guard cells control when stomata are opened vs. closed

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

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

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

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

52. Transpirational pull
As H2O transpires, it pulls other H2O molecules up
Relies on cohesion between water molecules

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

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

55. 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)

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

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