Kingdom: Plants
Domain Eukarya
Domain
Eubacteria
AP Biology
Domain
Archaea
Domain
Eukarya
2007-2008
Common ancestor
Evolution of Land Plants
 500 mya land plants evolved

special adaptations for life on dry land
 protection from drying = desiccation
 waxy cuticle
 gas exchange (through cuticle)
 stomates
 water & nutrient conducting systems
 from roots/soil to leaves
 xylem & phloem
 protection for embryo
AP Biology  seeds
monocot
1 seed leaf
dicot
2 seed leaves
Plant Diversity
Bryophytes
non-vascular
land plants
Pteridophytes
seedless
vascular plants
Gymnosperm
pollen &
“naked” seeds
conifers
mosses
Angiosperm
flowers & fruit
flowering plants
flowers
ferns
pollen & seeds
vascular system = water conduction
Tracheophytes
colonization of land
AP Biology
Ancestral Protist
xylem cells = tracheids
Animal vs. Plant life cycle
Animal
Plant
diploid
multicellular
individual
2n
diploid
multicellular
sporophyte
mitosis
2n
zygote 2n
mitosis
meiosis
zygote 2n
fertilization
haploid
unicellular
gametes
1n
AP Biology
no multicellular
haploid
fertilization
meiosis
gametes
1n
spores
1n
mitosis
mitosis
haploid
multicellular
gametophyte
1n
alternation of generations
Bryophytes: 1st land plants
 Bryophytes: mosses & liverworts
vascular system?
haploid
 No! non-vascular
 no water transport system
 no true roots
 dominant stage?
 haploid gametophyte stage
Where must  reduced, dependent sporophyte
mosses live?  fuzzy moss plant you are familiar
with is haploid
 reproduction?
 swimming sperm
 flagellated
 spores
 sprout to form gametophyte

AP Biology
diploid
Bryophytes: mosses & liverworts
AP Biology
Peat Bog
AP Biology
“Peat Moss”
Pteridophytes: 1st vascular plants diploid
 Pteridophytes: ferns
vascular system?
 Yes! vascular
 water transport system
 xylem, phloem, roots, leaves
 dominant stage?
Where must  diploid sporophyte stage
ferns live?  fragile, independent
haploid
gametophyte (prothallus)
 reproduction?
 swimming sperm
 flagellated
 spores
 sprout to form
AP Biology

Pteridophytes: Ferns
Selaginella
AP Biology
Horsetails
Psilotum
Ferns
Alternation of generations
 Fern gametophyte (1n)

homospory: male & female gamete
production on same plant
archegonia
antheridia
AP Biology
Alternation of generations
diploid
produces male
& female gametes
archegonia
antheridia
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haploid
Early Pteridophytes: Tree Ferns
Fossil fuels…
I get it!
Carboniferous forest – 290-350 mya
Forests of seedless plants decayed into deposits of coal & oil
AP Biology
Pteridophytes: Tree ferns
fronds
fiddleheads
AP Biology
With fronds
like these who
needs enemies!
First seed plants: Gymnosperm
 Gymnosperm: conifers

vascular system?
 Yes! vascular
 xylem, phloem, roots, leaves
dominant stage?
 diploid sporophyte stage
 reduced (microscopic) gametophyte
 reduction of gametophyte protects delicate egg &
Where can
embryo in protective sporophyte
conifers live?
 protected from drought & UV radiation
 heterospory: male vs. female gametophytes
 reproduction?
 seeds
 naked seeds (no fruit)
 pollen
 contain male gametophyte

AP Biology
Early Gymnosperm: ginkgo
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Early Gymnosperm: cycads
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Gymnosperm: conifers
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Cones & naked seeds
AP Biology
sporangium & pollen
male
male (pollen) cones
female
female
AP Biology
cones
pine embryo
First flowering plants
 Angiosperm: flowering plants

vascular system?
 Yes! vascular

dominant stage?
 diploid sporophyte stage
 reduced (microscopic) gametophyte
 protects egg & embryo
 heterospory: male vs. female gametophytes

reproduction?
 flower
◆sexual selection: attract pollinators
 seeds inside fruit
◆sexual selection: attract seed spreaders
 pollen
AP Biology

contain male gametophyte
Angiosperm: flowering plants
AP Biology
polar
nuclei
Angiosperm life cycle
male gametophyte =
pollen grain (haploid)
pollen
grains
egg
cell
ovary sac
sperm nuclei travel
down pollen tube
3n endosperm
female gametophyte =
ovary sac (haploid)
2n zygote
double
fertilization
2n embryo
new sporophyte
in seed (diploid)
AP Biology
Flower
 Modified shoot with 4 rings
of modified leaves
sepals Stamen
 petals
 stamens

Stigma
Style
Ovary
Anther
Carpel
Filament
 male

carpel / pistil
 female
sepals
petals
stamens
Petal
Ovule
Sepal
AP Biology
adaptations through mutations
carpel
Identify the flower structures…
AP Biology
Flower variations
AP Biology
Co-evolution: flowers & pollinators
How a bee sees a flower…insects see
UV light = a bulls-eye to the nectar
AP Biology
Angiosperm: fruiting plants
AP Biology
Other fruits…
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Seed & Plant embryo
 Seed offers…
endosperm
protection for
embryo
 stored nutrients
for growth of
embryo

(3n)
cotyledons
embryo (2n)
cotyledons = “seed” leaves,
first
leaves of new plant
AP Biology
seed coat
Monocots & dicots
 Angiosperm are divide into 2 classes

dicots (eudicot)
 2 cotyledons (seed leaves)
 leaves with network of veins
 woody plants, trees, shrubs, beans

monocots
 1 cotyledon
 leaves with parallel veins
 grasses, palms, lilies
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AP Biology
Any
Questions??
AP Biology