1. Topic 9—Plant Biology
Plant Diversity

2. Major Plant Groups Figure 22-6 p. 554 Flowering plants
Cone-bearing plants
Ferns and their relatives
Mosses and their relatives
Green algae ancestor
Flowers; Seeds Enclosed in Fruit
Seeds
Water-Conducting (Vascular) Tissue
Figure 22-6
p. 554

3. The Diversity of Plants
Section 22-1
Cone-bearing plants 760 species
Flowering plants 235,000 species
Ferns and their relatives 11,000 species
Mosses and their relatives 15,600 species
Figure 22-7
p. 555

4. Success on land Avoid drying out with a outer waxy covering
Absorb, conduct and conserve water
Reproduce without water…
Spores and seeds

5. Alternation of Generations (p.552)
diploid, asexual stage
haploid, sexual stage

7. Avascular, seedless plants
Mosses and liverworts

8. p. 558

9. Moss life cycle Gametophyte stage: (dominant) Sporophyte stage:
Protonema = tiny filaments producing leafy shoot
Leafy shoot with rhizoids (rootlike structures)
Archegonia = female organs producing eggs
Antheridia = male organs producing sperm
Sporophyte stage:
Stalk & capsule (containing sporangia spores)
Spores produce protonema

12. Vascular, seedless plants
Ferns and horsetails, etc.

13. Fern life cycle Sporophyte stage (dominant)
Fronds (leaves), rhizomes (underground stems) and roots ( with vascular tissue)
Sori (under frond) contain sporangia  spores
Gametophyte stage = heart-shaped Prothallus
sperm from antheridia swim to egg in archegonia producing zygote
Zygote grows into young sporophyte

17. Vascular plants with seeds
Gymnosperms
Exposed seeds
Angiosperms
Seeds enclosed in a fruit
Flowering plants

18. Gymnosperms Means “naked” seeds…seeds are NOT enclosed in a fruit
Examples: cone-bearing plants, cycads, & gingkos

20. Sporophyte stage: pollen cone (male)  microsporangium  microspore
Consists of plant body containing roots, stems, & leaves
pollen cone (male)  microsporangium  microspore
seed cone (female)  megasporangium  megaspore
1st yr = pollination nd yr = seed developing rd yr = open to release seeds on scales

22. Gametophyte stage: Microspores  pollen (male gametophytes)  sperm
megaspores  ovules (female gametophytes)  eggs
after fertilization, zygote begins seed, which develops into new sporophyte

23. Angiosperms Monocotyledons (one seed-leaf)
Examples = grasses, grains, orchid family, palms
Dicotyledons (two seed-leaves)
Examples = vegetables, nut & fruit trees, & all other flowers in the garden

24. Comparison of Monocots vs. Dicots
Seed : One seed leaf Two seed leaves
Leaf : Parallel veins Branching veins
Flower parts: Multiples of Multiples of 4 or 5
Root system: fibrous taproot
Stem : random radial
vascular bundles vascular bundles

25. Monocot Characteristics

26. Dicot Characteristics

28. Sporophyte stage Zygote  Embryo (within seed) plant body
plant body consisting of roots, stems & leaves
flower containing male & female reproductive organs
reproductive organs  microspores & megaspores

29. Gametophyte stage:
Microspores  pollen (male gametophyte containing sperm)
Megaspores  ovule (female gametophyte containing eggs)
after pollination & fertilization… sperm + egg  zygote (which begins the seed)