1. Chpt. 29 Plant Diversity Colonization of Land

2. Plant Classification:
PHYLUM

3. Division Plant Classification: Phyta = suffix for division name
ex. Bryophyta = moss
Pterophyta = fern

4. Plant Evolution: from where did they come??
Green algae mm
Common ancestor

5. The first plants
For more than 3 billion years, Earth’s terrestrial surface was lifeless
life evolved in the seas
1st photosynthetic organisms were aquatic green algae - the PROTIST kingdom

6. Plant Evolution:
Diverged from green algae called Charophytes.

7. Present day relatives to ancient plants:
Chara
Coleochaete
Protists
Volvox

8. Evidence: 1. Homologous chloroplasts 2. Biochemical similarity
3. Cell wall similarity (cellulose)
4. Sperm similarity (flagellated)
5. Genetic relationship (similar a.a. sequences and rRNA)

9. Evidence:
Modern Charophytes grow in shallow water, NOT ALWAYS UNDERWATER.
This may have allowed them to be pre-adapted to move to land.

10. WOW!!! It is hard to live on the land… what adaptations would be necessary for a successful move from water algae to land plants??

11. Adaptations for Land Colonization:
Specialization: need to capture light & CO2 above ground (shoots)
need to capture water & minerals below ground (roots)

12. Perpetual embryonic region
Did you ever consider: plants just can’t get up and move to the water, CO2 etc.???
shoots
Perpetual embryonic region

13. Perpetual embryonic region
Did you ever consider: plants just can’t get up and move to the water, CO2 etc.???
Perpetual embryonic region
roots

14. Adaptations for Land Colonization: 2. Cuticle
= waxy layer keeps from drying out in the air -
H2O conservation

15. Adaptations for Land Colonization:
2. Cuticle
= waxy layer keeps from drying out in the air - H2O conservation

16. Problem
Cuticle blocks CO2 and O2 gas exchanges between the cells and the environment.

17. Adaptations for Land Colonization:
3. Stomata
= gas exchange on leaf /
prevents water loss

18. Adaptations for Land Colonization:
4. Sporopollenin
= polymer on spores and pollen. Makes walls of spores tough…
Assists reproduction in the harsh land environment

19. Adaptations for Land Colonization: 5. Gametangia (multicellular)
= multicellular, protective area for gametes
organ that produces gametes
keeps gametes from drying out

20. Adaptations for Land Colonization:
5. a) Archegonia (female)
produces eggs
keeps from drying out
= protective area for gametes

21. Adaptations for Land Colonization:
5. a)Archegonia (female)
produces eggs
keeps from drying
= protective area for gametes

22. Adaptations for Land Colonization:
5. b)Antheridia (male)
produces sperm
keeps from drying out
= protective area for gametes

23. Two multicellular body forms:
6) Alternation of Generations
Two multicellular body forms:
SPOROPHYTE - (2N)
GAMETOPHYTE - (N)

24. Two multicellular body forms:
6) Alternation of Generations
Two multicellular body forms:
SPOROPHYTE - (2N)
GAMETOPHYTE - (N)

25. 6) Alternation of Generations
multicellular / haploid produces the gametes

26. 6) Alternation of Generations

27. 6) Alternation of Generations

28. 6) Alternation of Generations

29. 6) Alternation of Generations

30. 6) Alternation of Generations
multicellular diploid produces haploid spores

31. 6) Alternation of Generations

32. 6) Alternation of Generations

33. 6) Alternation of Generations

34. Plants: Evolutionary Trends
____________ non-vascular land plants
____________ seedless vascular plants
____________ pollen & “naked” seeds
____________ flowers & fruit
seed plants
vascular plants
Plants: Evolutionary Trends
colonization of land

35. Plants: Evolutionary Trends
1. Reduction of Gametophyte.
2. Change from flagellated sperm to pollen.
3. Development of seeds, flowers, and fruits.
4. Development of vascular tissues.
Plants: Evolutionary Trends

36. Plant Evolution: bryophytes
Mosses
Liverworts
Hornworts for at least 50 million years these were the only plants! mm

37. Plant Evolution: bryophytesmm

38. Plant Evolution: bryophytes
°Gametophyte = DOMINANT generation mm

39. this is the dominant stage
GAMETOPHYTE

40. Plant Evolution: bryophytes
° nonvascular mm
-“rootless” - thallus
-no wter transport
-“leaves”, one cell thick
-close to ground -WHY?

41. How do they get water?

42. Where must mosses live?

43. “Peat Moss”
Peat Bog

44. Produces gametes this is dominant stage
Plant Evolution: bryophytes
°Gametangia mm
Produces gametes this is dominant stage
eggs in archegonia
sperm in antheridia

45. antheridia
archegonia

46. Plant Evolution: bryophytes
°Gametangia -
why is this is a HUGE evolutionary deal!!! mm

47. Plant Evolution: bryophytes
°Gametangia -
Protects of zygote from the elements! mm

48. Plant Evolution: bryophytes
°Sporophyte = NOT DOMINANT generation mm

49. Plant Evolution:bryophytes
°often found in wet habitats… WHY? mm

50. Plant Evolution:bryophytes
°are never taller than 10cm tall… WHY? mm

51. Sporophyte Produces spores (n) in a sporangium or capsule.
Parasitic on the gametophyte.

52. Sporophyte
Sporangium
Spores (n)

53. Plant Evolution:bryophytes
° Sporopollenin -spores w/ protective coating mm

54. Plant Evolution:bryophytes
° Sporopollenin -spores w/ protective coating.
protection of spore for harsh environment mm

55. Plant Evolution:bryophytes
° Sporopollenin -spores w/ protective coating.
protection of spore for harsh environment mm

56. Bryophytes -Importances
Peat Moss (many uses).
Soil Formation.
First plants in primary Succession

57. And then....

58. (we are still w/o seeds)
Vascular Plants
(we are still w/o seeds)

59. Seedless Vascular Plants
The ferns and fern allies.
A collection of several different plant divisions.

60. STEMS & LEAVES
SHOOTS
ROOTS

61. Characteristics True vascular tissue. Xylem –> water/minerals.
Phloem –> food.

62. PHLOEM ANATOMY:

63. XYLEM ANATOMY:

64. Plant Evolution:
Evolutionary significance of vascular tissue? - mm

65. Plant Evolution:
Evolutionary significance of vascular tissue allows the organism to achieve a larger size mm

66. Plant Evolution:
Evolutionary significance of vascular tissue allows the organism to achieve a larger size this allows for more spores!! mm

67. Plant Evolution: No seed, flower, or fruit.
Green algae mm
No seed, flower, or fruit.
Still we have flagellated sperm (no pollen)

68. diploid
haploid

69. Plant Evolution:
SPOROPHYTE - becomes the DOMINANT stage over gametophyte
what is the evolutionary significance? mm

70. Plant Evolution: pterophyte
More complex
(remember, mosses spend more time in the gametophyte stage.) mm

71. Plant Evolution: pterophyte
Branched -
what is the evolutionary significance? mm

72. Plant Evolution: pterophyte
Branched -
what is the evolutionary significance? more opportunity for more sporangia (area where spores develop) .. More reproduction!!! mm

73. Spore Type Homosporous - one kind of spore.
produces bisexual gametophyte both archegonia and antheridia on one structure)

74. SORUS - on leaf… holds sporangia

75. Spore Type Homosporous - one kind of spore
produces bisexual gametophyte both archegonia and antheridia on one structure)

76. SPORANGIA - holds spores

77. Spores mitose -> gametophyte (n)

78. prothallium

79. GAMETOPHYTE
archegonia
antheridia

80. gametophyte matures and produces GAMETAMGIA

81. H2O
HANDY evolutionary trick… sperm and egg DO NOT the same time!!!

82. Sporophyte grows out of the gametophyte

83. SPOROPHYTE grows out of gametophyte

84. Bush = sporophyte generation Iraq = gametophyte generation

86. Ferns Often have underground stems called rhizome.
Leaf called a frond.
‘baby leaf’ a fiddlehead.

87. fronds
fiddleheads

88. Fern – Life cycle
Sporophyte
Sori on fronds

89. Fern – Life cycle
Sorus
Sporangium

90. Fern – Life cycle
Germinating Spore
Gametophytes

91. Fern – Life cycle
Young Sporophytes

92. Fern – Life cycle
Young Sporophytes

93. SIGNIFICANCE
Formed the first forests!!

94. SIGNIFICANCE
Accelerated rate of photosynthesis (increased rate of CO2 removal from the atmosphere)

95. Global cooling / widespread glacial formation
SIGNIFICANCE
Global cooling / widespread glacial formation

96. SIGNIFICANCE
COAL

97. SIGNIFICANCE
COAL

98. Early Pteridophytes: Tree Ferns
Fossil fuels…
I get it!
Carboniferous forest – mya
Forests of seedless plants decayed into deposits of coal & oil

99. Summary
ģ Know the general characteristics of plants (what makes them successful on land).
ģ Know the alternation of generations for plants.
ģ What are the evolutionary trends in plants?

100. Summary For each plant division, know: Examples Characteristics
Life Cycle
Economic/Ecological Importance