1. Chapter 29: Plant Diversity I The Colonization of Land

2. Kingdom Plantae
What are the 4 main characteristics of the Kingdom Plantae?
Eukaryotic
Multicellular
Autotrophic
Cell Wall Present

3. 4 Additional Characteristics
1) Cuticle
2) Stomata
3) Secondary Products
4) Starch Storage

4. 1) Cuticle 2) Stomata Waxy layer on stems and
leaves to prevent water loss.
Necessary for plants to survive in terrestrial environments.
Problem: Cuticle blocks CO2 and O2 gas exchanges between the cells and the environment. Solution:
Pores on plant surfaces for gas exchange.
Comment – plants must balance need for CO2 uptake with H2O loss.
2) Stomata

5. 3) Secondary Products 4) Starch Storage
Materials not produced by the primary metabolic pathways.
Examples:
cuticle waxes
Lignin (wood)
Sporopollenin (pollen grains)
4) Starch Storage
Most plants store extra food as starch.
Ex: chloroplasts amyloplasts

6. Plant Life Cycle Alternation of Generations.
Plants exist in two body forms.
Sporophyte (2N) - makes spores.
Gametophyte (1N) - makes gametes.

7. Spores Gametophyte Produced by meiosis.
Grows directly into a gametophyte by mitosis.
Produces gametangia by mitosis.
Gametes protected by a jacket of "sterile" cells.
Gametophyte

8. Antheridia Archegonia Male gametangia.
Sterile cells
Antheridia
Sperm
Male gametangia.
Produce sperm (may be flagellated).
Female gametangia.
Produce eggs.
Archegonia
Sterile Cells
Egg

9. Plants: 4 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.

11. Evolution of Plants
From green algae called Charophytes.

12. 5 pieces of Evidence 1) Homologous chloroplasts
Charophytes and green plants have the same pigments, similar thylakoid structure, and similar chloroplast DNA sequences.
2) Biochemical Similarity
Charophytes and green plants have similar cell walls (with cellulose) and peroxisomes.
3) Cell Division Similarity
Charophytes and green plants have similar mitotic spindles and cytokinesis.
4) Sperm Similarity
Charophytes and green plants have similar sperm ultrastructure.
5) Genetic Relationship
Charophytes and green plants have similar nuclear genes and rRNA.

14. Origin of two body forms?
May have been an adaptation or delay of meiosis due to the lack of water.
Comment – primitive plants have swimming sperm and depend on water for fertilization.
Movement from water to land
Modern Charophytes grow in shallow water. This may have allowed them to be pre-adapted to move to land.

16. Plant Taxonomy Class = Division
- phyta : suffix for the division name.

17. Plant Emphasis 1. Examples 2. Characteristics 3. Life History
4. Importances

18. Divisions: Examples Bryophyta - Mosses Hepatophyta - Liverworts
Anthocerophyta - Hornworts
~17,000 species

19. Nonvascular Seedless Land Plants
The "Bryophytes”
Ex: Mosses, Liverworts, Hornworts

20. Characteristics Moss Leaf No vascular tissue (in most).
No seeds, flowers or fruits.
Flagellated sperm.
Gametophyte dominant.
Often found in wet habitats Why?
Reasons:
Water uptake by osmosis only.
Need water for sperm to swim.
Are never more than 10 cm tall. Why?
No wood or support tissue
Can’t move water up against gravity (no xylem or phloem).

21. Life History Gametophyte dominant.
Sporophyte parasitic on gametophyte.

23. Gametophyte Antheridia Archegonia Photosynthetic
Produces antheridia and archegonia.
Needs rain for sperm dispersal.
Antheridia
Archegonia

24. Sporophyte Spores Sporangium
Produces spores in a sporangium or capsule.
Parasitic on the gametophyte.
Spores
Sporangium

25. Bryophytes -Importances
Peat Moss (many uses).
Soil Formation.

26. Pteridophytes: Seedless Vascular Plants
Examples Divisions:
Psilophyta – Wisk ferns
Lycophyta - Club Mosses
Sphenophyta - Horsetails
Pterophyta - Ferns
~13,000 species, mostly ferns

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

28. Characteristics: True vascular tissue. No seed, flowers or fruits.
Xylem – water.
Phloem – food.
No seed, flowers or fruits.
Flagellated sperm.
Sporophyte dominant.

29. Life History: Sporophyte dominant.
Gametophyte reduced, but usually independent from the sporophyte.

30. Life Cycle

31. Spore Types Homosporous - one kind of spore (most fern allies).
Hetrosporous - two kinds of spores.
Microspores  males  sperm
Megaspores  females  eggs

32. Psilotum – a Wiskfern Oldest known vascular plant.
Has dichotomous branching (a primitive character).
True stems only, no roots or leaves.
Sporangia

33. Lycopodium - a Club Moss
Spores are in clusters of sporangia called a strobilus, which is a primitive type of cone.
Strobilus

34. Equisetum - Horsetails
Have silica in cell walls.
Also called scouring rushes.
Have strobili on some stems.
Strobilus

35. True Ferns Most diverse division.
Forms range from aquatic to tree-like.
Spores formed in sporangia called a sorus.

36. Ferns Leaf called a frond.
Often have underground stems called rhizomes.

37. Fern – Life cycle
Sporophpyte
Sori on fronds

38. Fern – Life Cycle
Sorus
Sporangium

39. Fern – Life Cycle
Germinating Spore
Gametophytes

40. Young Sporophytes

41. Importances
Psilophyta:
1 form eaten.
1st true vascular plant.

42. Importances Lycophyta: Christmas decorations. Terrarium plants.
Spores used as baby powder.

43. Importances
Sphenophyta:
Scouring rushes.
Tinker toy plants.

44. Importances Pterophyta: Landscaping and houseplants. Food (limited).
Lumber (limited).
Home for nitrogen-fixing cyanobacteria.
Coal.

45. Summary Know the general characteristics of plants.
Know the alternation of generations for plants.
What are the evolutionary trends in plants?

46. Summary For each plant division, know: Examples Characteristics
Life History
Importances