1. Introduction to Plants

2. Figure 29.1
Figure 29.1 How did plants change the world?

3. Charophytes

4. Relationship between algae and land plants
Red algae
ANCESTRAL ALGA
Chlorophytes
Viridiplantae
Figure 29.2 Three possible “plant” kingdoms
Charophytes
Streptophyta
Plantae
Embryophytes
Figure 29.2

5. Green Algae & Plants: shared traits
Chlorophyll A & B
Cell walls of cellulos
Starch as polysaccharide for storage

6. Charophytes as closest relatives
Shared traits w/ land plants
Protien rings on cell membrane to make cellulose
Similar sperm (assymetrical arranged flagella)
Phragmoplasts (microtubule arrangement during mitosis)
Nuclear and chloroplast DNA similarities
Some charophytes protect zygote w/ in gametophyte
30 nm

7. Derived Traits of Plants
Five key traits appear in nearly all land plants but are absent in the charophytes
Alternation of (heteromophic) generations
Multicellular, dependent embryos
Walled spores produced in sporangia
Multicellular gametangia
Apical meristems
Cuticle
Stomata (except liverworts)

8. Alternation of generations
Figure 29.3a
Alternation of generations
Gametophyte (n)
Gamete from another plant
Mitosis
Mitosis n n n n
Spore
Gamete
MEIOSIS
FERTILIZATION
Zygote
Figure 29.3a Exploring derived traits of land plants (part 1: alternation of generations) 2n
Key
Sporophyte (2n)
Haploid (n)
Mitosis
Diploid (2n)

9. Multicellular, dependent embryos
Figure 29.3b
Multicellular, dependent embryos
Embryo (LM) and placental transfer cell (TEM) of Marchantia (a liverwort)
Embryo
Maternal tissue
Figure 29.3b Exploring derived traits of land plants (part 2: multicellular, dependent embryos)
Wall ingrowths
2 µm
10 µm
Placental transfer cell (blue outline)

10. Walled spores produced in sporangia
Figure 29.3c
Walled spores produced in sporangia
Spores
Sporangium
Longitudinal section of Sphagnum sporangium (LM)
Figure 29.3c Exploring derived traits of land plants (part 3: walled spores produced in sporangia)
Sporophyte
Gametophyte
Sporophytes and sporangia of Sphagnum (a moss)

11. Multicellular gametangia
Figure 29.3d
Multicellular gametangia
Female gametophyte
Archegonia, each with an egg (yellow)
Antheridia (brown), containing sperm
Figure 29.3d Exploring derived traits of land plants (part 4: multicellular gametangia)
Male gametophyte
Archegonia and antheridia of Marchantia (a liverwort)

12. Apical meristems Apical meristem of shoot Developing leaves
Figure 29.3e
Apical meristems
Apical meristem of shoot
Developing leaves
Apical meristem of root
Figure 29.3e Exploring derived traits of land plants (part 5: apical meristems)
Root
Shoot
100 µm
100 µm
Apical meristems of plant roots and shoots

13. - flowering plants (seed + flowers)
Figure 29.5
Plant Diversity:
- non-vascular
- seedless vascular
- seed (but no flowers)
- flowering plants (seed + flowers)
ANCESTRAL GREEN ALGA
Liverworts
Nonvascular plants (bryophytes)
Origin of land plants
Land plants 1
Mosses
Hornworts
Lycophytes (club mosses, spike mosses, quillworts)
Seedless vascular plants
Origin of vascular plants 2
Monilophytes (ferns, horsetails, whisk ferns)
Vascular plants
Figure 29.5 Highlights of plant evolution
Gymnosperms
Origin of extant seed plants
Seed plants 3
Angiosperms
Millions of years ago (mya)

14. Table 29.1
Table 29.1 Ten phyla of extant plants

15. Challenges of dry land Dryness/relative lack of water
Gravity (need for support)

16. Nonvascular plants (24,000 species)
Liverworts, hornworts, & mosses

17. Nonvascular plants Gameptophyte dominant Dependent sporophyte
Flagellated sperm
Consequences on reproduction?
Environment found?
Non vascular tissue
Size?

18. Protonemata (n) Zygote (2n) Mature sporophytes
Figure 29.6
“Bud”
Sperm
Protonemata (n)
Antheridia
Key
Male gametophyte (n)
Haploid (n) Diploid (2n)
“Bud”
Egg
Spores
Gametophore
Spore dispersal
Archegonia
Female gametophyte (n)
Rhizoid
Peristome
Sporangium
Seta
FERTILIZATION
Figure 29.6 The life cycle of a moss
MEIOSIS
Capsule (sporangium)
(within archegonium)
Zygote (2n)
Mature sporophytes
Foot
Embryo
Archegonium
2 mm
Young sporophyte (2n)
Capsule with peristome (LM)
Female gametophyte

19. Animation: Moss Life Cycle

20. Capsule with peristome (LM)
Figure 29.6a
Figure 29.6a The life cycle of a moss (part 1: LM)
2 mm
Capsule with peristome (LM)

21. (a) Peat being harvested from a peatland
Figure 29.9
Figure 29.9 Sphagnum, or peat moss: a bryophyte with economic, ecological, and archaeological significance
(a) Peat being harvested from a peatland
(b) “Tollund Man,” a bog mummy dating from 405–100 B.C.E.

22. Seedless Vascular Plants
Ferns, club mosses, horsetails, wiskferns, etc..
Monilophytes (Phylum Monilophyta)
Strobilus on fertile stem
Vegetative stem
3 cm
25 cm
4 cm
Athyrium filix-femina, lady fern
Equisetum telmateia, giant horsetail
Psilotum nudum, a whisk fern

23. Seedless Vascular Plants: Lycophytes (Phylum Lycophyta)
Figure 29.13a
Seedless Vascular Plants: Lycophytes (Phylum Lycophyta)
2.5 cm
Strobili (clusters of sporophylls)
Isoetes gunnii, a quillwort
Selaginella moellendorffii, a spike moss
Figure 29.13a Exploring seedless vascular plant diversity (part 1: lycophytes)
1 cm
Diphasiastrum tristachyum, a club moss

24. Seedless Vascular Plants
Sprophyte dominant
Independent gametophyte
Flagellated sperm
Impact on reproduction
Vascular Tissue
Transport
Support
Promotes increase in size

25. Vascular Tissue Xylem Phloem
Transports water and minerals (nutrients from soil)
Provides support
Phloem
Transports sugars

26. True roots, stems, & leaves
Length via apical meristem
Contain vascular tissues
Anchor and absorb
Leaves
Specialized for photosynthesis
Microphylls—single vein (of vascular tissue)
Megaphylls—multiple veins (of vascular tissue)
Sporophylls—leaves that create/house sporangia

27. Figure 29.14
Horsetail
Fern
Figure Artist’s conception of a Carboniferous forest based on fossil evidence

28. Seed plants: gymnosperms + angiosperms

29. Seed plant developments
Pollen
Distribution (w/o water) and protection of sperm
Non-flagellated sperm
Ovule = megasporangium
Contains egg
Retained w/ in parent tissue
After fertilization develops into seed

32. Seed From ovule Contains embryo (young sporophyte)
Nutrients for embryo
Protects and disperses embryo
Important food source for animals, supported evolution of faster, larger, more intelligent organisms.

33. Figure 30.3-3 Immature ovulate cone Integument (2n) Female
gametophyte (n)
Seed coat
Megaspore (n)
Spore
wall
Egg nucleus
(n)
Spore wall
Food
supply
(n)
Discharged
sperm nucleus
(n)
Megasporangium
(2n)
Figure From ovule to seed in a gymnosperm (step 3)
Pollen
grain (n)
Male
gametophyte (n)
Pollen tube
Embryo (2n)
Micropyle
(a) Unfertilized ovule
(b) Fertilized ovule
(c) Gymnosperm seed

34. Figure 30.UN05 Five Derived Traits of Seed Plants Reduced gametophytes
Microscopic male and
female gametophytes
(n) are nourished and
protected by the
sporophyte (2n)
Male
gametophyte
Female
gametophyte
Heterospory
Microspore (gives rise to
a male gametophyte)
Megaspore (gives rise to
a female gametophyte)
Ovules
Integument (2n)
Ovule
(gymnosperm)
Megaspore (n)
Megasporangium (2n)
Figure 30.UN05 Summary of key concepts: seed plant traits
Pollen
Pollen grains make water
unnecessary for fertilization
Seeds
Seeds: survive
better than
unprotected
spores, can be
transported
long distances
Seed coat
Food supply
Embryo

35. Flowering Plants (angiosperms)
Figure 30.17db Exploring angiosperm diversity (part 4b: eudicots)
Dog rose (Rosa canina), a wild rose

36. Angiosperm developments
Flowers
Promote effective, targeted reproduction
Transfer of sperm to egg
Attract w/ sight and smell
Reward w/ food (pollen and/or nectar)
Fruit
Protects and disperses seed more effectively

37. Tomato Ruby grapefruit Nectarine Hazelnut Milkweed ▼ ▼ ▼ ▼ ▼
Figure Some variations in fruit structure ▼
Milkweed

38. Figure 30.11c The barbs of cockleburs facilitate
Figure 30.11c Fruit adaptations that enhance seed dispersal (part 3: berries and other edible fruits)
Seeds within berries and other
edible fruits are often dispersed
in animal feces.
The barbs of cockleburs facilitate
seed dispersal by allowing the fruits
to “hitchhike” on animals.
Figure 30.11c

39. Angiosperm Diversity: monocots v. dicots
Embryos
Leaf venation
Stems
Roots
Pollen
Flowers
Monocot
Characteristics
Root system
usually fibrous
(no main root)
Floral organs
usually in
multiples
of three
One
cotyledon
Veins usually
parallel
Vascular tissue
scattered
Pollen grain
with one
opening
Eudicot
Characteristics
Figure Characteristics of monocots and eudicots
Vascular tissue
usually arranged
in ring
Floral organs
usually in
multiples of
four or five
Two
cotyledons
Veins usually
netlike
Taproot
(main root)
usually present
Pollen grain
with three
openings

40. Figure 30.2 PLANT GROUP Ferns and other seedless vascular plants
Mosses and other
nonvascular plants
Seed plants (gymnosperms and angiosperms)
Reduced,
Independent
(photosynthetic
and free-living)
Reduced (usually microscopic), dependent on
surrounding sporophyte tissue for nutrition
Gametophyte
Dominant
Reduced, dependent
on gametophyte for
nutrition
Sporophyte
Dominant
Dominant
Gymnosperm
Angiosperm
Sporophyte
(2n)
Microscopic female
gametophytes (n)
inside ovulate cone
Microscopic female
gametophytes (n)
inside these parts
of flowers
Sporophyte
(2n)
Gametophyte
(n)
Microscopic
male
gametophytes
(n) inside
these parts
of flowers
Example
Figure 30.2 Gametophyte-sporophyte relationships in different plant groups
Microscopic
male
gametophytes
(n) inside pollen
cone
Sporophyte (2n)
Sporophyte (2n)
Gametophyte
(n)