1. Inquiry into Life Twelfth Edition
Lecture PowerPoint to accompany
Inquiry into Life Twelfth Edition
Sylvia S. Mader
Chapter 29
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. 29.1 Evolutionary History of Plants
Plants evolved from algae over 500 million years ago
Characteristics plants and algae share
Contain chlorophyll a and b and accessory pigments
Store excess carbohydrates as starch
Have cellulose in their cell walls
Biochemical evidence shows plants are most closely related to stonewarts, a type of green algae

3. 29.1 Evolutionary History of Plants
Four Major Events in Evolution of Plants
Development of embryo protection
Development of vascular tissue
Development of seeds
Development of flowers

4. Evolutionary History of Plants

5. 29.1 Evolutionary History of Plants
Alternation of Generations
All plants have a life cycle that included the alternation of generations
Sporophyte (2n)
Gametophyte (n)
Plants differ as to which generation is dominant (most conspicuous)

6. Alternation of Generations

7. Reproduction in the Size of the Gametophyte

8. 29.2 Nonvascular Plants
Nonvascular plants lack true roots, stems, and leaves
By definition, roots, stems, and leaves have vascular tissue
The gametophyte generation is dominant
Three divisions
Hornworts
Liverworts
Mosses

9. 29.2 Nonvascular Plants Liverworts
Two basic types: “leafy” and those with a flat, lobed thallus
Marchantia- thallus type
Smooth upper surface
Lower surface has many rhizoids which extend into soil
Reproduce both sexually and asexually
Asexual reproduction by gemmae- groups of cells that detach and form new thallus
Sexual reproduction by gametophores- structures that produce gametes

10. Liverwort, Marchantia

11. 29.2 Nonvascular Plants Mosses Found all over the world
Mosses become dormant if the environment becomes dry
Most mosses can reproduce asexually by fragmentation in addition to sexual reproduction

12. Moss Life Cycle, Polytrichum sp.

13. 29.2 Nonvascular Plants Adaptations and Uses of Nonvascular Plants
Can live on bare rock, fences, cracks of sidewalks
Selective advantage to being small and simple
Help convert rocks to soil
Peat moss
Used as fuel
Holds water
Used in gardens to improve soil

14. 29.3 Seedless Vascular Plants
Seedless vascular plants include whisk ferns, club mosses, horsetails, and ferns
The sporophyte is the dominant generation
Vascular tissue
Xylem
Conducts water and minerals up from the soil
Phloem
Transports organic nutrients between parts of the plant
Seedless vascular plants formed the swamp forests of Carboniferous period

15. The Carboniferous Period

16. 29.3 Seedless Vascular Plants
Whisk Ferns- Psilophyta
Arial stem with many forks
Attached to rhizome- underground stem
No leaves, photosynthesis occurs in stems
Independent gametophyte found underground

17. 29.3 Seedless Vascular Plants
Club Mosses
Rhizome sends up aerial stems
Scale-like leaves
Some are epiphytes
Live on trees but do not parasitize them

18. 29.3 Seedless Vascular Plants
Horsetails
Moist habitats world wide
Rhizome produces aerial stems
In some species, whorls of side-branches come off the main stem at regions called nodes
Leaves are scale-like
Cones are at tips of stems in most
Have silica deposited in cell walls

19. 29.3 Seedless Vascular Plants
Ferns
Most abundant in warm, moist, tropical regions
Leaves are called fronds
Immature leaves are called fiddleheads
Grow from rhizome
Dominant sporophyte stage
Produces wind-blown spores
Spore germinates and forms small gametophyte
Independent from the sporophyte
Swimming sperm produced by antheridia
Fertilization occurs in archegonia

20. Fern Life Cycle

21. Fern Diversity

22. 29.4 Seed Plants Gymnosperms and Angiosperms
Seeds contain a sporophyte embryo and stored food within a protective coat
This allows an embryo to survive during long periods of dormancy

23. 29.4 Seed Plants Gymnosperms Exhibit heterospory
Two types of spores- produce two types of gametophytes, male and female
Pollen grains- male gametophyte
Pollination-deposition of pollen on a female gametophyte
Pollen tube-sperm pass through pollen tube to reach ovule
No water required as it is in previous groups
Female gametophyte develops within ovule

24. Pine Life Cycle

25. 29.4 Seed Plants Gymnosperms Adaptations and Uses of Conifers
Conifers are the most familiar gymnosperms
Pines, spruces, firs, cedars, hemlocks, redwoods, and cypress
Adaptations and Uses of Conifers
Adapted to cold, dry weather
Pollen cones and seed cones are adaptations to land
Needle-shaped leaves have small surface area to decrease water loss
Also have a thick cuticle and recessed stomata
Wood is used in construction and for making paper
Resins are used for production of chemicals

26. Conifers

27. 29.4 Seed Plants Other Gymnosperms Cycads Gingkoes Gnetophytes
Resemble palms or ferns
Pollen or seed cones grow on top of long vertical stem
Plentiful in Mesozoic era at the time of dinosaurs
Gingkoes
Only one surviving species-Gingko biloba, the maidenhair tree
Female trees produce fleshy seeds that give off a foul odor
Male trees are preferred for ornamental planting
Gnetophytes
Ephedra is only species in N. America
Adapted to hot temperatures

28. Other Gymnosperms

29. 29.4 Seed Plants Angiosperms Angio (vessel), sperm (seed)
There are more known species of angiosperms than all other types of plants combined
Live in all types of habitats
Seed develops from an ovule within an ovary
Ovary becomes the fruit
Two classes: Monocots and Eudicots

31. Flower Diversity

32. 29.4 Seed Plants The Flower Flower parts
Receptacle: tip of stalk that bears flowers
Sepals: modified leaves that protect bud
Petals: modified leaves, may be colorful
Stamens: male reproductive structures
Anther: pollen production
Filament
Carpels: female reproductive structures
Stigma: for reception of pollen
Style
Ovary: ovule production

33. Generalized Flower

34. Flowering Plant Life Cycle

35. 29.4 Seed Plants Life cycle, Adaptations, Uses of Flowering Plants
Pollination can be by wind, water, insects, and other animals such as bats
Fruits, the final product of a flower aids in the dispersal of seeds.

36. Fruits