1. Introduction to the Plant Kingdom: Bryophytes Chapter 22

2. Mosses in Olympic National Park, WA.

3. Sphagnum grows out onto the surface of a pond and gradually turns it into a quaking bog, which really does quake when you walk or jump on it. Eventually it becomes a bog with no free water.

4. Peat farmer, digging turf in Ireland.

5. Tollund Man, found in Denmark, was preserved by the tannic acids of a peat moss bog.

6. Tollund Man The Tollund Man lived during the late 5th century BC and/or early 4th century BC, about 2,400 years ago. He was buried in a peat bog on the Jutland Peninsula in Denmark, a find known as a bog body. The Tollund Man lived during the late 5th century BC and/or early 4th century BC, about 2,400 years ago. He was buried in a peat bog on the Jutland Peninsula in Denmark, a find known as a bog body.5th century BC4th century BCpeat bog JutlandPeninsulaDenmarkbog body5th century BC4th century BCpeat bog JutlandPeninsulaDenmarkbog body He is remarkable for the fact that his body was so well preserved that he seemed to have died only recently. He is remarkable for the fact that his body was so well preserved that he seemed to have died only recently. On May 6, 1950, the Højgård brothers from the small village of Tollund were cutting peat for their tile stove and kitchen range in the Bjældskovdal peat bog, 10 km west of Silkeborg, Denmark. On May 6, 1950, the Højgård brothers from the small village of Tollund were cutting peat for their tile stove and kitchen range in the Bjældskovdal peat bog, 10 km west of Silkeborg, Denmark.May 61950SilkeborgMay 61950Silkeborg Underneath the body was a thin layer of moss. Scientists know that this moss was formed in Danish peat bogs in the early Iron Age about the time when Jesus was born. Therefore, the body was suspected to have been placed in the bog approximately 2,000 years ago during the early Iron Age. Underneath the body was a thin layer of moss. Scientists know that this moss was formed in Danish peat bogs in the early Iron Age about the time when Jesus was born. Therefore, the body was suspected to have been placed in the bog approximately 2,000 years ago during the early Iron Age.mossIron AgeJesusmossIron AgeJesus Subsequent C14 radiocarbon dating of Tollund Man's hair indicated that he died in approximately 350 BC. Subsequent C14 radiocarbon dating of Tollund Man's hair indicated that he died in approximately 350 BC.radiocarbon dating350 BCradiocarbon dating350 BC The acid in the peat, along with the lack of oxygen underneath the surface, had preserved the soft tissues of his body. The acid in the peat, along with the lack of oxygen underneath the surface, had preserved the soft tissues of his body. Examinations and X-rays showed that the man's head was undamaged, and his heart, lungs and liver were well preserved. Examinations and X-rays showed that the man's head was undamaged, and his heart, lungs and liver were well preserved.X-raysheadheartlungsliverX-raysheadheartlungsliver

7. LEARNING OBJECTIVE 1 Discuss some environmental challenges of living on land Discuss some environmental challenges of living on land Describe how several plant adaptations meet these challenges Describe how several plant adaptations meet these challenges

9. CLICK TO PLAY Animation: Evolutionary Tree for Plants

10. Colonization of Land Plants required evolution of structural, physiological, reproductive adaptations Plants required evolution of structural, physiological, reproductive adaptations Plants produce gametes in multicellular gametangia that contain a protective layer of sterile cells Plants produce gametes in multicellular gametangia that contain a protective layer of sterile cells

11. KEY TERMS CUTICLE CUTICLE A noncellular, waxy covering over the epidermis of aerial plant parts that reduces water loss A noncellular, waxy covering over the epidermis of aerial plant parts that reduces water loss STOMA STOMA A small pore in the plant epidermis that allows gas exchange for photosynthesis A small pore in the plant epidermis that allows gas exchange for photosynthesis

12. Variation in Plants

13. LEARNING OBJECTIVE 2 Name the algal group from which plants are hypothesized to have descended Name the algal group from which plants are hypothesized to have descended Describe supporting evidence Describe supporting evidence

14. Plant Ancestors 1 Plants probably evolved from green algae Plants probably evolved from green algae Similar biochemical characteristics: Similar biochemical characteristics: pigments (chlorophylls a and b, carotenes, xanthophylls) pigments (chlorophylls a and b, carotenes, xanthophylls) cell-wall components (cellulose) cell-wall components (cellulose) carbohydrate storage material (starch) carbohydrate storage material (starch)

15. Plant Ancestors 2 Similar fundamental processes Similar fundamental processes such as cell division such as cell division Land plants probably descended from charophytes (stoneworts) Land plants probably descended from charophytes (stoneworts) Based on molecular and structural data Based on molecular and structural data

16. Green algae gave rise to bryophytes. Chara is a green alga that has features similar to the alga that may have been ancestral to the bryophytes. Its growth habit is plantlike, although this may simply result from convergent evolution.

17. Gametangia: Plants and Algae

18. Unicellular gametangium Developing gametes Multicellular gametangium Sterile cell Fig. 22-2, p. 431

19. LEARNING OBJECTIVE 3 Explain what is meant by alternation of generations Explain what is meant by alternation of generations Diagram a generalized plant life cycle Diagram a generalized plant life cycle

20. KEY TERMS ALTERNATION OF GENERATIONS ALTERNATION OF GENERATIONS A type of life cycle characteristic of plants and a few algae and fungi A type of life cycle characteristic of plants and a few algae and fungi They spend part of their life in a multicellular n gametophyte generation and part in a multicellular 2n sporophyte generation They spend part of their life in a multicellular n gametophyte generation and part in a multicellular 2n sporophyte generation

21. CLICK TO PLAY Animation: Haploid to Diploid Dominance

22. Plant Life Cycle

23. Gametophyte Sporophyte Zygote HAPLOID (n) GAMETOPHYTE GENERATION DIPLOID (2n) SPOROPHYTE GENERATION Meiosis Fertilization SpermEgg Spore Embryo Fig. 22-3, p. 431

24. Stepped Art Spore Meiosis DIPLOID (2n) SPOROPHYTE GENERATION Sporophyte Zygote Embryo SpermEgg Fertilization HAPLOID (n) GAMETOPHYTE GENERATION Gametophyte Fig. 22-3, p. 431

25. KEY TERMS ANTHERIDIUM ANTHERIDIUM A multicellular male gametangium that produces sperm cells A multicellular male gametangium that produces sperm cells ARCHEGONIUM ARCHEGONIUM A multicellular female gametangium that produces an egg A multicellular female gametangium that produces an egg

26. Plant Gametangia

27. The Gametophyte Generation Produces haploid gametes by mitosis Produces haploid gametes by mitosis Antheridium produces sperm cells Antheridium produces sperm cells Archegonium produces an egg Archegonium produces an egg Fertilization: Gametes fuse to form a diploid zygote Fertilization: Gametes fuse to form a diploid zygote

28. KEY TERMS SPORE SPORE A reproductive cell that gives rise to individual offspring in plants, fungi, and certain algae and protozoa A reproductive cell that gives rise to individual offspring in plants, fungi, and certain algae and protozoa

29. The Sporophyte Generation First stage is zygote First stage is zygote Develops into an embryo, protected and nourished by gametophyte plant Develops into an embryo, protected and nourished by gametophyte plant Mature sporophyte plant has spore mother cells that undergo meiosis to produce haploid spores Mature sporophyte plant has spore mother cells that undergo meiosis to produce haploid spores First stage in gametophyte generation First stage in gametophyte generation

30. LEARNING OBJECTIVE 4 Summarize the features that distinguish bryophytes from other plants Summarize the features that distinguish bryophytes from other plants

31. Bryophytes Small, fairly simple plants Small, fairly simple plants Nonvascular Nonvascular Gametophyte is dominant generation Gametophyte is dominant generation grows independently of sporophyte and is usually perennial grows independently of sporophyte and is usually perennial

32. Plant Evolution

33. Evolution of cuticle, multicellular gametangia, multicellular embryos Evolution of dominant sporophyte, vascular tissue Evolution of seeds Green algal ancestor VASCULAR SEED PLANTS NONVASCULAR BRYOPHYTES VASCULAR SEEDLESS PLANTS Angiosperms Gymnosperms Ferns Club mosses Mosses Liverworts Hornworts Fig. 22-5, p. 434

34. LEARNING OBJECTIVE 5 Name and briefly describe the three phyla of bryophytes Name and briefly describe the three phyla of bryophytes

35. Three Phyla of Bryophytes Mosses Mosses Liverworts Liverworts Hornworts Hornworts

36. KEY TERMS MOSS MOSS A member of a phylum of spore-producing nonvascular plants in which the dominant n gametophyte alternates with a 2n sporophyte that remains attached to the gametophyte A member of a phylum of spore-producing nonvascular plants in which the dominant n gametophyte alternates with a 2n sporophyte that remains attached to the gametophyte

37. Mosses Leafy moss gametophytes develop from a protonema Leafy moss gametophytes develop from a protonema A moss sporophyte consists of a capsule, a seta, and a foot A moss sporophyte consists of a capsule, a seta, and a foot

38. KEY TERMS PROTONEMA PROTONEMA In mosses, a filament of n cells that grows from a spore and develops into leafy moss gametophytes In mosses, a filament of n cells that grows from a spore and develops into leafy moss gametophytes CAPSULE CAPSULE Portion of the bryophyte sporophyte in which spores are produced Portion of the bryophyte sporophyte in which spores are produced

39. Mosses

40. Mosses

41. A moss that survives drought. Tortula rurali is a genus of moss that lives in regions with only occasional rainfall. During dry periods, the plant looks completely dried out and dead. However, a few minutes after rain, the plants are rehydrated and fully functional.

42. Mosses

43. Foot Capsule Seta Fig. 22-6c, p. 435

44. CLICK TO PLAY Animation: Moss Life Cycle

45. Alternation of Generation (Moss) http://www.sumanasinc.com/webcontent/a nisamples/majorsbiology/moss.html http://www.sumanasinc.com/webcontent/a nisamples/majorsbiology/moss.html

46. Life Cycle: Mosses

47. DIPLOID (2n) SPOROPHYTE GENERATION HAPLOID (n) GAMETOPHYTE GENERATION Gametophyte plants Buds on protonema Spore germinates Protonema Spores released Meiosis Spore mother cells that undergo meiosis Calyptra Capsule Gametophyte plant Embryo Zygote Archegonium with egg Antheridia at the tip of the gametophyte shoot Antheridia with sperm cells Sperm cell Sporophyte Fertilization 1 2 3 4 5 6 Fig. 22-7, p. 437

48. KEY TERMS LIVERWORT LIVERWORT A member of a phylum of spore-producing, nonvascular, thalloid or leafy plants with a life cycle similar to that of mosses A member of a phylum of spore-producing, nonvascular, thalloid or leafy plants with a life cycle similar to that of mosses

49. KEY TERMS THALLUS THALLUS A body that lacks roots, stems, or leaves A body that lacks roots, stems, or leaves GEMMA GEMMA A small body of tissue that becomes detached from a parent liverwort and is capable of developing into a new organism A small body of tissue that becomes detached from a parent liverwort and is capable of developing into a new organism

50. Liverworts

51. Liverworts

52. Life Cycle: Liverworts

53. DIPLOID (2n) SPOROPHYTE GENERATION HAPLOID (n) GAMETOPHYTE GENERATION Meiosis Fertilization 1 2 3 4 5 Antheridiophore Germination of spores and development of young gametophyte Spores released Archegoniophore Male thallus Female thallus Gemmae cup Male and female gametophyte plants Sporophyte Spore mother cells that undergo meiosis Tissue derived from archegonium Capsule Seta Foot Embryo Zygote Archegonia with eggs Antheridia with sperm cells Sperm cell Fig. 22-9, p. 439

54. Liverwort Gametangia and Sporophyte

55. Gametophyte thallus Antheridiophore Fig. 22-10a, p. 440

56. Liverwort Gametangia and Sporophyte

57. Fig. 22-10b, p. 440

58. Liverwort Gametangia and Sporophyte

59. Foot Capsule Seta Fig. 22-10c, p. 440

60. KEY TERMS HORNWORT HORNWORT A member of a phylum of spore-producing, nonvascular thalloid plants with a life cycle similar to that of mosses A member of a phylum of spore-producing, nonvascular thalloid plants with a life cycle similar to that of mosses

61. Hornworts Hornwort gametophytes are thalloid; their sporophytes form hornlike projections out of the gametophyte thallus Hornwort gametophytes are thalloid; their sporophytes form hornlike projections out of the gametophyte thallus

62. Hornwort

63. Sporophyte Gametophyte with embedded archegonia and antheridia Mature sporangium splits open Spores Fig. 22-11b, p. 441

64. LEARNING OBJECTIVE 6 Describe the ecological significance of the mosses Describe the ecological significance of the mosses

65. Mosses Colonize rock previously colonized by lichens Colonize rock previously colonized by lichens Help form thin soil in which grasses and other plants can grow Help form thin soil in which grasses and other plants can grow Grow in dense colonies Grow in dense colonies Hold soil in place, help prevent soil erosion Hold soil in place, help prevent soil erosion

66. Mosses in Research