1. © 2010 Pearson Education, Inc. Lectures by Chris C. Romero, updated by Edward J. Zalisko PowerPoint ® Lectures for Campbell Essential Biology, Fourth Edition – Eric Simon, Jane Reece, and Jean Dickey Campbell Essential Biology with Physiology, Third Edition – Eric Simon, Jane Reece, and Jean Dickey Chapter 16 Plants, Fungi, and the Move onto Land

2. Biology and Society: Will the Blight End the Chestnut? American chestnut trees –Once dominated forests of the eastern United States –Were prized for their –Rapid growth –Huge size –Rot-resistant wood © 2010 Pearson Education, Inc.

3. Figure 16.00

4. © 2010 Pearson Education, Inc. Around 1900, an Asian fungus was accidentally introduced from China into North America, and in just 25 years, blight caused by the fungus killed virtually all adult American chestnut trees.

5. © 2010 Pearson Education, Inc. Fortunately, this type of harmful interaction between plant and fungus is unusual. Many plants and fungi benefit from each other’s existence.

6. © 2010 Pearson Education, Inc. COLONIZING LAND Plants are terrestrial organisms that include forms that have returned to water, such as water lilies.

7. Terrestrial Adaptations of Plants Structural Adaptations A plant is –A multicellular eukaryote –A photoautotroph, making organic molecules by photosynthesis © 2010 Pearson Education, Inc.

8. In terrestrial habitats, the resources that a photosynthetic organism needs are found in two very different places: –Light and carbon dioxide are mainly available in the air –Water and mineral nutrients are found mainly in the soil

9. © 2010 Pearson Education, Inc. The complex bodies of plants are specialized to take advantage of these two environments by having –Aerial leaf-bearing organs called shoots –Subterranean organs called roots

10. Reproductive structures (such as those in flowers) contain spores and gametes Leaf performs photosynthesis Cuticle reduces water loss; stomata regulate gas exchange Shoot supports plant (and may perform photosynthesis) Surrounding water supports the alga Roots anchor plant; absorb water and minerals from the soil (aided by fungi) Whole alga performs photosynthesis; absorbs water, CO 2, and minerals from the water Alga Plant Figure 16.1

11. © 2010 Pearson Education, Inc. Most plants have mycorrhizae, symbiotic fungi associated with their roots, in which the fungi –Absorb water and essential minerals from the soil –Provide these materials to the plant –Are nourished by sugars produced by the plant

12. Roots Fungus Root surrounded by fungus Figure 16.2

13. © 2010 Pearson Education, Inc. Leaves are the main photosynthetic organs of most plants, with –Stomata for the exchange of carbon dioxide and oxygen with the atmosphere –Vascular tissue for transporting vital materials –A waxy cuticle surface that helps the plant retain water

14. Phloem Xylem Oak leaf Vascular tissue Figure 16.3

15. © 2010 Pearson Education, Inc. Vascular tissue in plants is also found in the –Roots –Shoots Two types of vascular tissue exist in plants: –Xylem transports water and minerals from roots to leaves –Phloem distributes sugars from leaves to the roots and other nonphotosynthetic parts of the plant

16. © 2010 Pearson Education, Inc. Reproductive Adaptations Plants produce their gametes in protective structures called gametangia, which have a jacket of protective cells surrounding a moist chamber where gametes can develop without dehydrating.

17. © 2010 Pearson Education, Inc. The zygote develops into an embryo while still contained within the female parent in plants but not in algae.

18. Embryo Maternal tissue LM Figure 16.4

19. © 2010 Pearson Education, Inc. The Origin of Plants from Green Algae The algal ancestors of plants –Carpeted moist fringes of lakes or coastal salt marshes –First evolved over 500 million years ago

20. © 2010 Pearson Education, Inc. Charophytes –Are a modern-day lineage of green algae –May resemble one of these early plant ancestors

21. LM Figure 16.5

22. © 2010 Pearson Education, Inc. PLANT DIVERSITY The history of the plant kingdom is a story of adaptation to diverse terrestrial habitats.

23. © 2010 Pearson Education, Inc. Highlights of Plant Evolution The fossil record chronicles four major periods of plant evolution.

24. Ancestral green algae Origin of first terrestrial adaptations (about 475 mya) Origin of vascular tissue (about 425 mya) Origin of seeds (about 360 mya) 6005004003002001000 Origin of flowers (about 140 mya) Millions of years ago Angiosperms Gymnosperms Ferns and other seedless vascular plants Bryophytes Charophytes (a group of green algae) Land plants Vascular plants Seed plants Seedless vascular plants Nonvascular plants (bryophytes) Figure 16.6

25. © 2010 Pearson Education, Inc. (1) About 475 million years ago plants originated from an algal ancestor giving rise to bryophytes, nonvascular plants, including mosses, liverworts, and hornworts that are nonvascular plants without –Lignified walls –True roots –True leaves

26. © 2010 Pearson Education, Inc. (2) About 425 million years ago ferns evolved –With vascular tissue hardened with lignin –But without seeds

27. © 2010 Pearson Education, Inc. (3) About 360 million years ago gymnosperms evolved with seeds that consisted of an embryo packaged along with a store of food within a protective covering but not enclosed in any specialized chambers. Today, conifers, consisting mainly of cone-bearing trees such as pines, are the most diverse and widespread gymnosperms.

28. © 2010 Pearson Education, Inc. (4) About 140 million years ago angiosperms evolved with complex reproductive structures called flowers that bear seeds within protective chambers called ovaries.

29. © 2010 Pearson Education, Inc. The great majority of living plants –Are angiosperms –Include fruit and vegetable crops, grains, grasses, and most trees –Are represented by more than 250,000 species

30. PLANT DIVERSITY Bryophytes (nonvascular plants) Ferns (seedless vascular plants) Gymnosperms (naked-seed plants) Angiosperms (flowering plants) Figure 16.7

31. © 2010 Pearson Education, Inc. Bryophytes Bryophytes, most commonly mosses –Sprawl as low mats over acres of land –Need water to reproduce because their sperm swim to reach eggs within the female gametangium –Have two key terrestrial adaptations: –A waxy cuticle that helps prevent dehydration –The retention of developing embryos within the mother plant’s gametangium

32. Figure 16.8

33. © 2010 Pearson Education, Inc. Mosses have two distinct forms: –The gametophyte, which produces gametes –The sporophyte, which produces spores

34. Spores Spore capsule Sporophyte Gametophytes Figure 16.9

35. © 2010 Pearson Education, Inc. The life cycle of a moss exhibits an alternation of generations shifting between the gametophyte and sporophyte forms. Mosses and other bryophytes are unique in having the gametophyte as the larger, more obvious plant.

36. Spores (n) Spore capsule Gametes: sperm and eggs (n) Zygote (2n) Gametophyte (n) Sporophyte (2n) Key Haploid (n) Diploid (2n) MEIOSIS FERTILIZATION osis Mit osis Mit t o Mi sis Figure 16.10-5

37. © 2010 Pearson Education, Inc. Ferns Ferns are –Seedless vascular plants –By far the most diverse with more than 12,000 known species The sperm of ferns, like those of mosses –Have flagella –Must swim through a film of water to fertilize eggs

38. Spore capsule “Fiddlehead” (young leaves ready to unfurl) Figure 16.11

39. © 2010 Pearson Education, Inc. During the Carboniferous period, from about 360 to 300 million years ago, ferns –Were part of a great diversity of seedless plants –Formed swampy forests over much of what is now Eurasia and North America As they died, these forests formed coal.

40. © 2010 Pearson Education, Inc. Fossil fuels –Include coal, oil, and natural gas –Formed from the remains of long-dead organisms

41. Figure 16.12

42. © 2010 Pearson Education, Inc. Gymnosperms At the end of the Carboniferous period, the climate turned drier and colder, favoring the evolution of gymnosperms, which can –Complete their life cycles on dry land –Withstand long, harsh winters The descendants of early gymnosperms include the conifers, or cone-bearing plants.

43. © 2010 Pearson Education, Inc. Conifers –Cover much of northern Eurasia and North America –Are usually evergreens, which retain their leaves throughout the year –Include the tallest, largest, and oldest organisms on Earth

44. Figure 16.13

45. © 2010 Pearson Education, Inc. Terrestrial Adaptations of Seed Plants Conifers and most other gymnosperms have three additional terrestrial adaptations: –Further reduction of the gametophyte –Pollen –Seeds

46. © 2010 Pearson Education, Inc. Seed plants have a greater development of the diploid sporophyte compared to the haploid gametophyte generation.

47. Key Haploid (n) Diploid (2n) Gametophyte (n) Sporophyte (2n) Sporophyte (2n) Gametophyte (n) Gametophyte (n) Sporophyte (2n) (a) Sporophyte dependent on gametophyte (e.g., mosses) (b) Large sporophyte and small, Independent gametophyte (e.g., ferns) (c) Reduced gametophyte dependent on sporophyte (seed plants) Figure 16.14

48. © 2010 Pearson Education, Inc. A pine tree or other conifer is actually a sporophyte with tiny gametophytes living in cones.

49. Scale Ovule-producing cones; the scales contain female gametophytes Pollen-producing cones; they produce male gametophytes Ponderosa pine Figure 16.15

50. © 2010 Pearson Education, Inc. A second adaptation of seed plants to dry land was the evolution of pollen. A pollen grain –Is actually the much-reduced male gametophyte –Houses cells that will develop into sperm

51. © 2010 Pearson Education, Inc. The third terrestrial adaptation was the development of the seed, consisting of –A plant embryo –A food supply packaged together within a protective coat

52. © 2010 Pearson Education, Inc. Seeds –Develop from structures called ovules, located on the scales of female cones in conifers –Can remain dormant for long periods before they germinate, as the embryo emerges through the seed coat as a seedling

53. (a) Ovule Haploid (n) Diploid (2n) (b) Fertilized ovule (c) Seed Cross section of scale Female cone, cross section Integument Spore Spore case Pollen tube Spore case Egg nucleus Female gametophyte Discharged sperm nucleus Seed coat (derived from integument) Embryo (new sporophyte) Food supply (derived from female gametophyte tissue) Pollen grain (male gametophyte) Figure 16.16-3

54. © 2010 Pearson Education, Inc. Angiosperms –Dominate the modern landscape –Are represented by about 250,000 species –Supply nearly all of our food and much of our fiber for textiles Their success is largely due to –A more efficient water transport –The evolution of the flower

55. © 2010 Pearson Education, Inc. Flowers, Fruits, and the Angiosperm Life Cycle Flowers help to attract pollinators who transfer pollen from the sperm-bearing organs of one flower to the egg-bearing organs of another.

56. © 2010 Pearson Education, Inc. A flower is actually a short stem with four whorls of modified leaves: –Sepals –Petals –Stamens –Carpels

57. Petal Carpel Stamen Sepal Ovule Anther Filament Stigma Style Ovary Figure 16.17

58. © 2010 Pearson Education, Inc. Flowers come in many forms.

59. Pansy Figure 16.18a

60. Bleeding heart Figure 16.18b

61. California poppy Figure 16.18c

62. Water lily Figure 16.18d

63. Mature sporophyte plant with flowers Sporophyte seedling Germinating seed Seed Seed (develops from ovule) Fruit (develops from ovary) Embryo (sporophyte) Two sperm nuclei Zygote Endosperm Embryo sac (female gametophyte) Egg FERTILIZATION Key Haploid (n) Diploid (2n) Anther at tip of stamen Pollen tube growing down style of carpel Ovary (base of carpel) Ovule Germinated pollen grain (male gametophyte) on stigma of carpel Figure 16.19-6

64. © 2010 Pearson Education, Inc. Although both have seeds –Angiosperms enclose the seed within an ovary –Gymnosperms have naked seeds

65. © 2010 Pearson Education, Inc. Fruit –Is a ripened ovary –Helps protect the seed –Increases seed dispersal –Is a major food source for animals

66. Wind dispersal Animal transportation Animal ingestion Figure 16.20

67. © 2010 Pearson Education, Inc. Angiosperms and Agriculture Gymnosperms supply most of our lumber and paper. Angiosperms –Provide nearly all our food –Supply fiber, medications, perfumes, and decoration Agriculture is a unique kind of evolutionary relationship between plants and animals.

68. © 2010 Pearson Education, Inc. Plant Diversity as a Nonrenewable Resource The exploding human population is –Extinguishing plant species at an unprecedented rate –Destroying fifty million acres, an area the size of the state of Washington, every year!

69. Figure 16.21

70. © 2010 Pearson Education, Inc. Humans depend on plants for thousands of products including –Food –Building materials –Medicines

71. Table 16.1

72. © 2010 Pearson Education, Inc. Preserving plant diversity is important to many ecosystems and humans. Scientists are now rallying to –Slow the loss of plant diversity –Encourage management practices that use forests as resources without damaging them

73. © 2010 Pearson Education, Inc. FUNGI Fungi –Recycle vital chemical elements back to the environment in forms other organisms can assimilate –Form mycorrhizae, fungus-root associations that help plants absorb from the soil –Minerals –Water

74. © 2010 Pearson Education, Inc. Fungi are –Eukaryotes –Typically multicellular –More closely related to animals than plants, arising from a common ancestor about 1.5 billion years ago

75. © 2010 Pearson Education, Inc. Fungi –Come in many shapes and sizes –Represent more than 100,000 species

76. Orange fungi Figure 16.22a

77. A “fairy ring” Figure 16.22b

78. Budding yeast Bud Colorized SEM Figure 16.22c

79. Mold Figure 16.22d

80. Mold Colorized SEM Figure 16.22e

81. Roundworm Body of fungus Predatory fungus Colorized SEM Figure 16.22f

82. © 2010 Pearson Education, Inc. Characteristics of Fungi Fungi have unique –Structures –Forms of nutrition

83. © 2010 Pearson Education, Inc. Fungal Nutrition Fungi –Are chemoheterotrophs –Acquire their nutrients by absorption

84. © 2010 Pearson Education, Inc. A fungus –Digests food outside its body –Secretes powerful digestive enzymes to break down the food –Absorbs the simpler food compounds

85. © 2010 Pearson Education, Inc. Fungal Structure The bodies of most fungi are constructed of threadlike filaments called hyphae. Hyphae are minute threads of cytoplasm surrounded by a –Plasma membrane –Cell wall mainly composed of chitin

86. © 2010 Pearson Education, Inc. Hyphae branch repeatedly, forming an interwoven network called a mycelium (plural, mycelia), the feeding structure of the fungus.

87. Reproductive structure Mycelium Hyphae Spore-producing structures Figure 16.23

88. © 2010 Pearson Education, Inc. Fungal Reproduction Mushrooms –Arise from an underground mycelium –Mainly function in reproduction Fungi reproduce by releasing billions and trillions of spores that are produced either sexually or asexually.

89. © 2010 Pearson Education, Inc. The Ecological Impact of Fungi Fungi have –An enormous ecological impact –Many interactions with humans

90. © 2010 Pearson Education, Inc. Fungi as Decomposers Fungi and bacteria –Are the principal decomposers of ecosystems –Keep ecosystems stocked with the inorganic nutrients necessary for plant growth Without decomposers, carbon, nitrogen, and other elements would accumulate in nonliving organic matter.

91. © 2010 Pearson Education, Inc. Molds can destroy –Fruit –Grains –Wood –Human-made material

92. © 2010 Pearson Education, Inc. Parasitic Fungi Parasitic fungi absorb nutrients from the cells or body fluids of living hosts. Of the 100,000 known species of fungi, about 30% make their living as parasites, including –Dutch elm disease –Deadly ergot, which infests grain

93. (a) American elm trees killed by Dutch elm disease fungus Figure 16.24a

94. (b) Ergots Figure 16.24b

95. © 2010 Pearson Education, Inc. About 50 species of fungi are known to be parasitic in humans and other animals, causing –Lung and vaginal yeast infections –Athlete’s foot

96. The Process of Science: Did a Fungus Lead to the Salem Witch Hunt? Observation: In 1692, eight young girls were accused of being witches and had symptoms consistent with ergot poisoning. Question: Did an ergot outbreak cause the witch hunt? Hypothesis: The girls’ symptoms were the result of ergot poisoning. Prediction: The historical facts would be consistent with this hypothesis. © 2010 Pearson Education, Inc.

97. Figure 16.25

98. © 2010 Pearson Education, Inc. Results: –Agricultural records from 1691, before the symptoms appeared, indicated a particularly warm and wet year, in which ergot thrives. –Records from the following year, when accusations of witchcraft died down, indicate a dry year consistent with an ergot die-off. –This correlation is consistent with the hypothesis but not conclusive.

99. © 2010 Pearson Education, Inc. Commercial Uses of Fungi Fungi are commercially important. Humans eat them and use them to –Produce medicines such as penicillin –Decompose wastes –Produce bread, beer, wine, and cheeses

100. Truffles (the fungal kind, not the chocolates) Blue cheese Chanterelle mushrooms Figure 16.26

101. PenicilliumZone of inhibited growth Staphylococcus Figure 16.27

102. Evolution Connection: Mutually Beneficial Symbiosis Symbiosis is the term used to describe ecological relationships between organisms of different species that are in direct contact. Mutually beneficial symbiotic relationships benefit both species. © 2010 Pearson Education, Inc.

103. Examples of mutually beneficial symbiotic relationships involving fungi include –Mycorrhizae, the association of fungi and plant roots –Lichens, the association of fungi and algae

104. Algal cell Fungal hyphae Colorized SEM Figure 16.28