1. CHAPTER 17 Plants, Fungi, and the Colonization of Land
Modules 17.1 – 17.3

2. Plants and Fungi—A Beneficial Partnership
Mutually beneficial associations of plant roots and fungi are common
These associations are called mycorrhizae
They may have enabled plants to colonize land

3. Citrus growers face a dilemma
They use chemicals to control disease-causing fungi
But these also kill beneficial mycorrhizae

4. Plants are multicellular photosynthetic eukaryotes
17.1 What is a plant?
Plants are multicellular photosynthetic eukaryotes
They share many characteristics with green algae
However, plants evolved unique features as they colonized land

5. PLANT
LEAF performs photosynthesis
CUTICLE reduces water loss; STOMATA allow gas exchange
STEM supports plant (and may perform photosynthesis)
ALGA
Surrounding water supports the alga
WHOLE ALGA performs photosynthesis; absorbs water, CO2, and minerals from the water
ROOTS anchor plant; absorb water and minerals from the soil (aided by mycorrhizal fungi)
HOLDFAST anchors the alga
Figure 17.1A

6. Unlike algae, plants have vascular tissue
It transports water and nutrients throughout the plant body
It provides internal support
Figure 17.1B

7. 17.2 Plants evolved from green algae called charophyceans
PLANT EVOLUTION AND DIVERSITY
17.2 Plants evolved from green algae called charophyceans
Molecular studies indicate that green algae called charophyceans are the closest relatives of plants
Figure 17.2A, B

8. Cooksonia was one of the earliest vascular land plants
Sporangia
Figure 17.2C

9. 17.3 Plant diversity provides clues to the evolutionary history of the plant kingdom
Two main lineages arose early from ancestral plants

10. Radiation of flowering plants
CENOZOIC
Gymnosperms (e.g., conifers)
Angiosperms
Seedless vascular plants (e.g., ferns, horsetails)
Bryophytes (e.g., mosses)
Radiation of flowering plants
MESOZOIC
Charophyceans (a group of green algae)
First seed plants
Early vascular plants
PALEOZOIC
Origin of plants
Figure 17.3A

11. One lineage gave rise to bryophytes
These are plants that lack vascular tissue
Bryophytes include mosses, which grow in a low, spongy mat
Figure 17.3B

12. Vascular plants are the other ancient lineage
Ferns and seed plants were derived from early vascular plants and contain
xylem and phloem
well-developed roots
rigid stems

13. Ferns are seedless plants whose flagellated sperm require moisture to reach the egg
Figure 17.3C

14. A major step in plant evolution was the appearance of seed plants
Gymnosperms
Angiosperms
These vascular plants have pollen grains for transporting sperm
They also protect their embryos in seeds

15. Gymnosperms, such as pines, are called naked seed plants
This is because their seeds do not develop inside a protective chamber
The seeds of angiosperms, flowering plants, develop in ovaries within fruits

16. CHAPTER 17 Plants, Fungi, and the Colonization of Land
Modules 17.4 – 17.14

17. 17.4 Haploid and diploid generations alternate in plant life cycles
ALTERNATION OF GENERATIONS AND PLANT LIFE CYCLES
17.4 Haploid and diploid generations alternate in plant life cycles
The haploid gametophyte produces eggs and sperm by mitosis
The eggs and sperm unite, and the zygote develops into the diploid sporophyte
Meiosis in the sporophyte produces haploid spores, which grow into gametophytes

18. Gametophytes (male and female) n Gametes (sperm and eggs) n
Mitosis
Mitosis
Spores n
Gametes (sperm and eggs) n
HAPLOID
Meiosis
Fertilization
DIPLOID
Zygote 2n
Mitosis
Sporophyte 2n
Figure 17.4

19. 17.5 Mosses have a dominant gametophyte
Most of a mat of moss consists of gametophytes
These produce eggs and swimming sperm
The zygote stays on the gametophyte and develops into the less conspicuous sporophyte

20. Sporophytes (growing from gametophytes)5
Mitosis and development
Sperm (n) (released from their gametangium)
Spores (n) 1
Gametangium containing the egg (n) (remains within gametophyte)
Gametophytes (n)
Egg
HAPLOID
Meiosis
Fertilization
DIPLOID
Sporangium
Stalk 2 4
Zygote (2n)
Gametophyte (n) 3
Mitosis and development
Sporophytes (growing from gametophytes)
Figure 17.5

21. 17.6 Ferns, like most plants, have a dominant sporophyte
Ferns, like mosses, have swimming sperm
The fern zygote remains on the small, inconspicuous gametophyte
Here it develops into the sporophyte

22. 5 1 HAPLOID DIPLOID 2 4 3 Sperm (n) Mitosis and development Spores (n)
Gametophyte (n) (underside)
Egg (n)
HAPLOID
Fertilization
Meiosis
Sporangia
DIPLOID 2 4
Zygote (2n) 3
Mitosis and development
New sporophyte growing out of gametophyte
Sporophyte (2n)
Figure 17.6

23. 17.7 Seedless plants formed vast “coal forests”
Ferns and other seedless plants once dominated ancient forests
Their remains formed coal
Figure 17.7

24. Gymnosperms that produce cones, the conifers, largely replaced the ancient forests of seedless plants
These plants remain the dominant gymnosperms today

25. 17.8 A pine tree is a sporophyte with tiny gametophytes in its cones
Sporangia in male cones make spores that develop into male gametophytes
These are the pollen grains
Sporangia in female cones produce female gametophytes

26. 4 5 HAPLOID DIPLOID 3 1 6 2 7 Female gametophyte (n)
Haploid spore cells in ovule develop into female gametophyte, which makes egg. 5
Egg (n)
Male gametophyte (pollen) grows tube to egg and makes and releases sperm.
Sperm (n)
Male gametophyte (pollen grain)
HAPLOID
MEIOSIS
Fertilization
DIPLOID
Scale
Sporangium (2n)
Ovule
Seed coat
Zygote (2n) 3
Pollination
Embryo (2n)
HAPLOID Pollen grains (male gametophytes) (n)
Integument 1
Female cone bears ovules. 6
Zygote develops into embryo, and ovule becomes seed.
MEIOSIS
Seed 2
Male cone produces spores by meiosis; spores develop into pollen grains 7
Seed falls to ground and germinates, and embryo grows into tree.
Sporophyte
Figure 17.8

27. 17.9 The flower is the centerpiece of angiosperm reproduction
Most plants are angiosperms
The hallmarks of these plants are flowers
Pollen grains
Anther
Stigma
CARPEL
Ovary
STAMEN
PETAL
Ovule
SEPAL
Figure 17.9A, B

28. The angiosperm life cycle is similar to that of conifers
The angiosperm plant is a sporophyte with gametophytes in its flowers
The angiosperm life cycle is similar to that of conifers
But it is much more rapid
In addition, angiosperm seeds are protected and dispersed in fruits, which develop from ovaries

29. 2
Haploid spore in each ovule develops into female gametophyte, which produces egg.
Egg (n)
Stigma 3
Pollination and growth of pollen tube
Pollen grain
Ovule
Pollen tube 1
Haploid spores in anthers develop into pollen grains: male gametophytes.
Sperm
Pollen (n)
HAPLOID
Meiosis
Fertilization
DIPLOID 4
Zygote (2n)
Seed coat
Food supply
Seeds 7
Ovary
Seed germinates, and embryo grows into plant.
Ovule
Embryo (2n) 5
Seed
Sporophyte 6
Fruit
Figure 17.10

30. 17.11 The structure of a fruit reflects its function in seed dispersal
Fruits are adaptations that disperse seeds
Figure 17.11A-C

31. 17.12 Connection: Agriculture is based almost entirely on angiosperms
Gymnosperms supply most of our lumber and paper
Angiosperms provide most of our food
Fruits, vegetables, and grains
Angiosperms also provide other important products
Medications, fiber, perfumes

32. Angiosperms are a major source of food for animals
Interactions with animals have profoundly influenced angiosperm evolution
Angiosperms are a major source of food for animals
Animals also aid plants in pollination and seed dispersal
Figure 17.13A-C

33. 17.14 Connection: Plant diversity is a nonrenewable resource
20% of the tropical forests worldwide were destroyed in the last third of the 20th century
The forests of North America have shrunk by almost 40% in the last 200 years
Figure 17.14

34. Some plants in these forests can be used in medicinal ways
More than 25% of prescription drugs are extracted from plants
Table 17.14

35. CHAPTER 17 Plants, Fungi, and the Colonization of Land
Modules – 17.17

36. 17.15 Fungi and plants moved onto land together
Plants probably moved onto land along with mycorrhizal fungi
These fungi help plants absorb water and nutrients
They are mutualistic organisms

37. Other fungi are parasites predators decomposers of dead organisms
Figure 17.15A-C

38. 17.16 Fungi absorb food after digesting it outside their bodies
Fungi are heterotrophic eukaryotes
They digest their food externally and absorb the nutrients

39. A fungus usually consists of a mass of threadlike hyphae
This forms a network called a mycelium
Hypha
Mycelium
Figure 17.16A-B

40. Most fungi cannot move
But they grow around and through their food very rapidly
Figure 17.16C, D

41. 17.17 Many fungi have three distinct phases in their life cycle
Fungal spores germinate to form haploid hyphae

42. The dikaryotic mycelium forms a fruiting body, the mushroom
In some fungi such as mushrooms, the fusion of hyphae results in a unique dikaryotic phase of their life cycle
Each cell contains two haploid nuclei from different parents
The dikaryotic mycelium forms a fruiting body, the mushroom
This structure contains specialized cells in which the nuclei fuse
These diploid cells then undergo meiosis, producing a new generation of spores

43. Fusion of haploid nuclei2
Diploid nuclei 3
Spores released 1
Fruiting body (mushroom)
Fusion of haploid nuclei
Meiosis
Haploid nucleus
DIPLOID
Spore
HAPLOID
DIKARYOTIC 4
Germination of spores and growth of mycelia 6
Growth of dikaryotic mycelium 5
Fusion of two hyphae of compatible mating types
Figure 17.17

44. CHAPTER 17 Plants, Fungi, and the Colonization of Land
Modules – 17.20

45. 17.18 Lichens consist of fungi living mutualistically with photosynthetic organisms
Lichens are associations of algae or cyanobacteria with a network of fungal hyphae
The fungus receives food in exchange for housing, water, and minerals
Algal cell
Fungal hyphae
Figure 17.18A, B

46. Lichens survive in hostile environments
They cover rocks and frozen tundra soil
Figure 17.18C

47. 17.19 Connection: Parasitic fungi harm plants and animals
Parasitic fungi cause disease
Dutch elm disease
Corn smut
Athlete’s foot
Figure 17.19A-C

48. 17.20 Connection: Fungi have an enormous ecological and practical impact
Numerous fungi are beneficial
Many are important in the decomposition of organic material and nutrient recycling

49. Fungi are also important as food
Mushrooms are the fruiting bodies of subterranean fungi
Yeasts (unicellular fungi) are essential for baking and beer and wine production
Fungi are used to ripen certain cheeses
Figure 17.20A

50. Some fungi produce antibiotics
Penicillin was the first antibiotic to be discovered
Staphylococcus aureus
Penicillium
Zone of inhibited growth
Figure 17.20B

51. CHAPTER 17 Extra Photographs Part A

52. Mycorrhizae
Figure 17.0x

53. Phloem and xylem in a Polypodium stem cross-section
Figure 17.1x1

54. Phloem and xylem in a close-up of a Polypodium stem cross-section
Figure 17.1x2

55. Chara
Figure 17.2Bx

56. Sphagnum moss
Figure 17.3x1

57. Sphagnum “leaf” light micrograph
Figure 17.3x2

58. “Leafy” liverwort, Porella
Figure 17.3x3

59. “Thalloid” liverwort, Pallavicinia lyellii
Figure 17.3x4

60. Hornwort
Figure 17.3x5

61. Lycophyte
Figure 17.3x6

62. Horsetail
Figure 17.3x7

63. CHAPTER 17 Extra Photographs Part B

64. Moss life cycle
Figure 17.5x1

65. Moss sporangium (SEM)
Figure 17.5x2

66. Mature fern
Figure 17.6x1

67. Fern sorus
Figure 17.6x2

68. Fern sporangium
Figure 17.6x3

69. Mature fern sporangium
Figure 17.6x4

70. Germinating fern spore
Figure 17.6x5

71. Fern gametophyte
Figure 17.6x6

72. Fern archegonia, a maidenhair fern
Figure 17.6x7

73. Fern sporophytes emerging from gametophytes
Figure 17.6x8

74. Fern spore
Figure 17.6x9

75. Douglas fir
Figure 17.7x

76. Frasier fir, Abies fraseri
Figure 17.8x1

77. Male pine pollen cones
Figure 17.8x2

78. CHAPTER 17 Extra Photographs Part C

79. Pollen cone, longitudinal section, light micrograph
Figure 17.8x3

80. Pine pollen, light micrograph
Figure 17.8x4a

81. Single pine pollen, light micrograph
Figure 17.8x4b

82. Female pine cones
Figure 17.8x5

83. Ovulate pine cone, longitudinal section, light micrograph
Figure 17.8x6

84. Pine ovulate scale, light micrograph
Figure 17.8x7a

85. Pine sporangium section with spores
Figure 17.8x7b

86. Pine embryo
Figure 17.8x8

87. Pollen grains, SEM
Figure 17.10x

88. Winged seed from a white pine
Figure 17.11x1

89. Seed dispersal
Figure 17.11x2

90. Deforestation
Figure 17.14x1

91. Slash and burn forest
Figure 17.14x2

92. Pine farm
Figure 17.14x3

93. Soil plate
Figure 17.15x

94. Septate and nonseptate hyphae
Figure 17.16Dx

95. CHAPTER 17 Extra Photographs Part D

96. Amanita
Figure 17.16x1

97. Coprinus comatus, Shaggy Mane (Basidiomycota)
Figure 17.16x2

98. Grevilles bolete
Figure 17.16x3

99. Morel
Figure 17.16x4

100. Stinkhorn, Mutinus ravenelii
Figure 17.16x5

101. Trametes versicolor, Turkey Tail
Figure 17.16x6

102. Tremella messenterica, Witch's Butter
Figure 17.16x7

103. Pilobolus aiming its sporangia
Figure 17.16x8

104. Aspergillus
Figure 17.16x9

105. Mushroom gills and basidia
Figure 17.17x1

106. Apothecium
Figure 17.17x2

107. Mature asci
Figure 17.17x3

108. Lichen anatomy, a section through foliose lichen shows the upper cortex, algal zone, medulla, lower cortex, and rhizines
Figure 17.18x

109. Botrytis on strawberries
Figure 17.19x

110. Moldy orange with Penicillium
Figure 17.20x