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Introduction: Plants and Fungi—A Beneficial
Partnership
 Plants and fungi colonized land together
 Mycorrhizae, mutually beneficial associations of
plant roots and fungi hyphae, enabled plants to
colonize land
– Mycorrhizal fungi absorb water, phosphorus, and other
minerals from soil and make them available to the
plant
– The sugars produced by the plant nourish the fungus
Copyright © 2009 Pearson Education, Inc.
FUNGI
Copyright © 2009 Pearson Education, Inc.
17.14 Fungi absorb food after digesting it outside
their bodies
 Fungi are absorptive heterotrophic eukaryotes that
digest their food externally and absorb the nutrients
 Most fungi consist of a mass of threadlike hyphae
making up a mycelium
– Hyphal cells are separated by cross-walls with pores
large enough for ribosomes, mitochondria, and nuclei
to cross
– Some are multinucleate without cross-walls
– Hyphae have a huge surface area to secrete digestive
enzymes and absorb food
 Fungal hyphae are surrounded by a cell wall with
chitin. This polysaccharide
is also seen in animals
Animation: Fungal Reproduction and Nutrition
Copyright © 2009 Pearson Education, Inc.
Hypha
Mycelium
17.15 Fungi produce spores in both asexual and
sexual life cycles
 Many fungal species can reproduce both sexually
and asexually
 Fungi produce huge numbers of asexual spores,
each of which can germinate to form a new fungus
 In many fungi, sexual fusion of haploid hyphae
leads to a heterokaryotic stage, in which cells
contain two genetically distinct haploid nuclei
– Hours or centuries may pass before parental nuclei
fuse to form a short-lived diploid phase
– Zygotes undergo meiosis inside specialized
reproductive structures and disperse haploid spores
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17.15 Fungi produce spores in both asexual and
sexual life cycles
Video: Allomyces Zoospore Release
Video: Phlyctochytrium Zoospore Release
Copyright © 2009 Pearson Education, Inc.
Key
Haploid (n)
Heterokaryotic (n + n)
(unfused nuclei)
Heterokaryotic
stage
Fusion of nuclei
Diploid (2n)
Fusion of cytoplasm
Spore-producing
structures
Spores
(n)
Asexual Mycelium
reproduction
Sexual
reproduction
Germination
Germination
Spores (n)
Zygote
(2n)
Meiosis
Spore-producing
structures
17.16 Fungi are classified into five groups
 Sexual reproductive structures are used to classify
fungi
– Fungi with no known sexual stage are known as
imperfect fungi
 Fungi likely evolved from an aquatic, flagellated
ancestor shared with animals
 Chytrids, which have flagellated spores, are the
earliest lineage of fungi
 Animals and fungi diverged into separate lineages
1.5 billion years ago
 The oldest fungal fossils are 460 million years old
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Chytrids
Zygomycetes
(zygote fungi)
Glomeromycetes
(arbuscular
mycorrhizal fungi)
Ascomycetes
(sac fungi)
Basidiomycetes
(club fungi)
17.16 Fungi are classified into five groups
 Zygomycetes
– Zygote fungi form resistant zygosporangia in
which haploid spores form by meiosis
– This group includes black bread mold
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17.17 Fungal groups differ in their life cycles and
reproductive structures
 Hyphae reproduce asexually by producing spores in
sporangia at the tips of upright hyphae
 When food is depleted, the fungus reproduces
sexually
– Mycelia of different mating types join and produce a
zygosporangium, which develops into a thickwalled structure that can tolerate dry, harsh
conditions
– Under favorable conditions, the parental nuclei fuse
and the diploid nucleus undergoes meiosis to form
haploid spores
Copyright © 2009 Pearson Education, Inc.
Key
Haploid (n)
Heterokaryotic (n + n)
Zygosporangium (n + n)
Diploid (2n)
Cells fuse
Mycelia of
different
mating types
2
3
Fusion of
nuclei
1
Young
zygosporangium
(heterokaryotic)
Meiosis
4
Sporangium
Spores
(n)
17.16 Fungi are classified into five groups
 Glomeromycetes
– These fungi form mycorrhizae, in which invasive
hyphae branch into treelike arbuscules within plant
roots
– 90% of plants have symbiotic partnerships with
glomeromycetes
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17.16 Fungi are classified into five groups
 Ascomycetes
– Sac fungi form saclike asci, which produce sexual
spores
– They range in size from yeasts to elaborate morels and
cup fungi
– Some form lichens in association with green algae or
cyanobacteria
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17.16 Fungi are classified into five groups
 Basidiomycetes
– Club fungi are the mushrooms, puffballs, and shelf
fungi
– They have club-shaped spore-producing structures called
basidia
– These fungi are important forest decomposers
Copyright © 2009 Pearson Education, Inc.
17.17 Fungal groups differ in their life cycles and
reproductive structures
 Hyphae of different mating types fuse to form a
heterokaryotic mycelium, which grows to produce
a mushroom
– Haploid nuclei fuse to form diploid nuclei in the clubshaped cells called basidia that line the gills of the
mushroom
– Each diploid nucleus undergoes meiosis to form
haploid spores
Copyright © 2009 Pearson Education, Inc.
Key
Haploid (n)
Heterokaryotic (n + n)
Diploid (2n)
1 Fusion of two hyphae
of different mating types
Key
Haploid (n)
Heterokaryotic (n + n)
Diploid (2n)
Mushroom
2 Growth of
heterokaryotic mycelium
1 Fusion of two hyphae
of different mating types
3 Diploid nuclei
Fusion of
nuclei
Key
Haploid (n)
Heterokaryotic (n + n)
Diploid (2n)
Basidia
Mushroom
2 Growth of
heterokaryotic mycelium
1 Fusion of two hyphae
of different mating types
3 Diploid nuclei
Fusion of
nuclei
Key
Meiosis
Haploid (n)
4 Spores
Heterokaryotic (n + n)
released
Diploid (2n)
Basidia
Haploid
nuclei
Spores (n)
Mushroom
2 Growth of
heterokaryotic mycelium
1 Fusion of two hyphae
of different mating types
3 Diploid nuclei
Fusion of
nuclei
Key
Meiosis
Haploid (n)
4 Spores
Heterokaryotic (n + n)
released
Diploid (2n)
Basidia
Haploid
nuclei
Spores (n)
Mushroom
5 Germination
2 Growth of
heterokaryotic mycelium
of spores
and growth
of mycelia
1 Fusion of two hyphae
of different mating types
17.18 CONNECTION: Parasitic fungi harm
plants and animals
 80% of plant diseases are caused by fungi
– Between 10 and 50% of the world’s fruit harvest is
lost each year to fungal attack
– A variety of fungi, including smuts and rusts, infect
grain crops
 Only 50 species of fungi are parasitic on animals,
causing mycoses
– Human infections include athlete’s foot (caused by
ringworm)
– Systemic mycoses are rare but serious fungal
infections that spread through the body from inhaled
spores
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Ergots
17.19 Lichens consist of fungi living in close
association with photosynthetic organisms
 Lichens consist of algae or cyanobacteria within a
fungal network
– Many lichen associations are mutualistic
– The fungus receives food from its photosynthetic
partner
– The fungal mycelium helps the alga absorb and retain
water and minerals
 Lichens are important pioneers on new land, where
they help to form soil
– Lichens are sensitive to air pollution, because they
obtain minerals from the air
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Fungal hyphae
Algal cell
17.21 CONNECTION: Fungi have enormous
ecological benefits and practical uses
 Fungi have many practical uses for humans
– Some fungi can break down toxic pollutants,
including pesticides like DDT and cancer-causing
chemicals
– Fungi may be able to clean up oil spills and chemical
messes
– We eat many fungi, from mushrooms to cheeses
modified by fungi
– Yeasts produce alcohol and cause bread to rise
– Fungi provide antibiotics that are used to treat
bacterial disease
– Fungi are playing important new roles in molecular
biology and biotechnology
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Staphylococcus
aureus
Penicillium
Zone of
inhibited
growth
PLANT EVOLUTION
AND DIVERSITY
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17.1 Plants have adaptations for life on land
 500 million years ago, the algal ancestors of plants
formed a green carpet on the edge of lakes and
coastal salt marshes
 Green algae called charophytes are the closest
living relatives of plants
Copyright © 2009 Pearson Education, Inc.
17.1 Plants have adaptations for life on land
 In all plants, the zygote develops into an embryo
while attached to and nourished by the parent plant
 Plants are embryophytes, with multicellular,
dependent embryos
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17.1 Plants have adaptations for life on land
 Challenges of terrestrial life
– Maintaining moisture within cells
– Obtaining resources from soil and air
– Supporting body in air
– Reproducing and dispersing offspring without water
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17.1 Plants have adaptations for life on land
 Land plants are a clade, defined by a set of derived
characters
– Alternation of haploid and diploid generations
– Walled spores produced in sporangia
– Male and female gametangia
– Multicellular, dependent sporophyte embryos
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17.2 Plant diversity reflects the evolutionary
history of the plant kingdom
 Four key adaptations for life on land distinguish the
main lineages of the plant kingdom
– Dependent embryos (characteristic of all plants)
– Lignified vascular tissues
– Seeds
– Flowers
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Liverworts
Ancestral
green
alga
Origin of land plants
(about 475 mya)
Hornworts
1
Mosses
Lycophytes (club mosses,
spike mosses, quillworts)
Origin of vascular plants
(about 425 mya)
2
Pterophytes (ferns,
horsetails, whisk ferns)
Gymnosperms
3
Origin of seed plants
(about 360 mya)
Angiosperms
500
450
400
350
Millions of years ago (mya)
300
0
Key
Vascular
tissue
Pollen
Spores
Leaf
Spores
Flagellated
sperm
Alga
Water supports
alga. Whole alga
performs photosynthesis;
absorbs water,
CO2, and
minerals from
water.
Seed
Flagellated
sperm
Leaf
Stem
Stem
Roots
Roots
Flagellated
sperm
Holdfast
(anchors alga)
Leaf
Moss
Stomata only on sporophytes;
primitive roots anchor plants,
no lignin; no vascular tissue;
fertilization requires moisture
Fern
Stomata; roots anchor plants,
absorb water; lignified cell
walls; vascular tissue;
fertilization requires moisture
Stem
Roots
Pine tree
Stomata;
roots anchor plants, absorb water;
lignified cell walls; vascular tissue;
fertilization does not require moisture
Key
Vascular
tissue
Spores
Leaf
Spores
Flagellated
sperm
Alga
Water supports
alga. Whole alga
performs photosynthesis;
absorbs water,
CO2, and
minerals from
water.
Flagellated
sperm
Leaf
Stem
Stem
Roots
Roots
Flagellated
sperm
Holdfast
(anchors alga)
Moss
Stomata only on sporophytes;
primitive roots anchor plants,
no lignin; no vascular tissue;
fertilization requires moisture
Fern
Stomata; roots anchor plants,
absorb water; lignified cell
walls; vascular tissue;
fertilization requires moisture
Key
Vascular
tissue
Pollen
Seed
Leaf
Stem
Roots
Pine tree
Stomata;
roots anchor plants, absorb water;
lignified cell walls; vascular tissue;
fertilization does not require moisture
ALTERNATION
OF GENERATIONS
AND PLANT LIFE CYCLES
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17.3 Haploid and diploid generations alternate in
plant life cycles
 The haploid gametophyte produces gametes
(eggs and sperm) by mitosis
 Fertilization results in a diploid zygote
 The zygote develops into the diploid sporophyte,
which produces haploid spores by meiosis
 Spores grow into gametophytes
Copyright © 2009 Pearson Education, Inc.
Key
Haploid (n)
Diploid (2n)
Gametophyte
plant (n)
Mitosis
Gametes (n)
Sperm
Egg
Key
Haploid (n)
Diploid (2n)
Gametophyte
plant (n)
Mitosis
Gametes (n)
Sperm
Egg
Fertilization
Zygote (2n)
Key
Haploid (n)
Gametophyte
plant (n)
Mitosis
Diploid (2n)
Gametes (n)
Sperm
Egg
Fertilization
Zygote (2n)
Mitosis
Sporophyte
plant (2n)
Key
Haploid (n)
Gametophyte
plant (n)
Mitosis
Diploid (2n)
Spores (n)
Gametes (n)
Sperm
Egg
Fertilization
Meiosis
Zygote (2n)
Mitosis
Sporophyte
plant (2n)
Key
Haploid (n)
Diploid (2n)
Gametophyte
plant (n)
Mitosis
Spores (n)
Mitosis
Gametes (n)
Sperm
Egg
Fertilization
Meiosis
Zygote (2n)
Mitosis
Sporophyte
plant (2n)
17.4 Mosses have a dominant gametophyte
 Gametophytes make up a bed of moss
– They produce eggs and flagellated sperm in
gametangia
– Sperm swim through water to the egg
 The zygote develops within the gametangium into
a mature sporophyte, which remains attached to
the gametophyte
– Meiosis occurs in sporangia at the tips of the
sporophyte stalk
– Haploid spores are released from the sporangium and
develop into gametophytes
Copyright © 2009 Pearson Education, Inc.
17.4 Mosses have a dominant gametophyte
Animation: Moss Life Cycle
Copyright © 2009 Pearson Education, Inc.
Key
Haploid (n)
Diploid (2n)
Gametophytes (n)
1
Male
Sperm (n)
Female
gametangium
Female
1
Egg (n)
Fertilization
Key
Haploid (n)
Diploid (2n)
Gametophytes (n)
1
Male
Sperm (n)
Female
gametangium
Female
1
Egg (n)
Fertilization
2
Zygote (2n)
Key
Haploid (n)
Diploid (2n)
Gametophytes (n)
1
Male
Sperm (n)
Female
gametangium
Female
1
Egg (n)
Fertilization
Sporangium
Stalk
2
Zygote (2n)
Sporophyte (2n)
3 Mitosis
and development
Gametophytes (n)
Key
Haploid (n)
Diploid (2n)
1
Male
Sperm (n)
Female
gametangium
Spores (n)
Female
1
Egg (n)
Fertilization
Sporangium
Stalk
2
Meiosis
4
Zygote (2n)
Sporophyte (2n)
3 Mitosis
and development
Key
Haploid (n)
Mitosis and
Diploid (2n) 5
development
Gametophytes (n)
1
Male
Sperm (n)
Female
gametangium
Spores (n)
Female
1
Egg (n)
Fertilization
Sporangium
Stalk
2
Meiosis
4
Zygote (2n)
Sporophyte (2n)
3 Mitosis
and development
17.5 Ferns, like most plants, have a dominant
sporophyte
 Fern gametophytes are small and inconspicuous
– They produce flagellated sperm that swim to the egg
and fertilize it to produce a zygote
– The zygote initially develops within the female
gametangia but eventually develops into an
independent sporophyte
 Sporangia develop on the underside of the leaves
of the sporophyte
– Within the sporangia, cells undergo meiosis to
produce haploid spores
– Spores are released and develop into gametophytes
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17.5 Ferns, like most plants, have a dominant
sporophyte
Animation: Fern Life Cycle
Copyright © 2009 Pearson Education, Inc.
Key
Haploid (n)
Diploid (2n)
1
Sperm (n)
Female
gametangium (n)
Gametophyte (n)
Egg (n)
Fertilization
Key
Haploid (n)
Diploid (2n)
1
Sperm (n)
Female
gametangium (n)
Gametophyte (n)
Egg (n)
Fertilization
2
Zygote (2n)
Key
Haploid (n)
Diploid (2n)
1
Sperm (n)
Female
gametangium (n)
Gametophyte (n)
Egg (n)
Fertilization
4
Clusters of
sporangia
2
Zygote (2n)
New sporophyte (2n)
3 Mitosis and
development
Mature sporophyte
1
Key
Haploid (n)
Diploid (2n)
Sperm (n)
5 Mitosis and
Female
gametangium (n)
development
Gametophyte (n)
Spores (n)
Egg (n)
Fertilization
Meiosis
4
Clusters of
sporangia
2
Zygote (2n)
New sporophyte (2n)
3 Mitosis and
development
Mature sporophyte
17.6 Seedless plants dominated vast “coal
forests”
 Seedless plants formed vast ancient forests in lowlying wetlands during the Carboniferous period
(360–299 million years ago)
– When they died, the plants formed peat deposits that
eventually formed coal
 Coal, oil, and natural gas are fossil fuels
– Oil and natural gas formed from marine organisms;
coal formed from seedless plants
– Burning fossil fuels releases CO2, causing climate
warming
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17.7 A pine tree is a sporophyte with
gametophytes in its cones
 A pine cone holds all of the tree’s reproductive
stages: spores, eggs, sperm, zygotes, and embryos
– Each scale of the cone contains sporangia that
produce spores by meiosis
– The spores produce gametophytes within the cone
 The male gametophyte is a pollen grain, released
from pollen cones and carried by wind to female
cones
 Female ovulate cones carry two ovules on each stiff
scale
– Each ovule contains a sporangium surrounded by the
integument
Animation: Pine Life Cycle
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1 Sporangia produce
spores; spores develop
into pollen grains.
Scale
Sporangium (2n)
Ovule
Meiosis
Meiosis
Pollen grains
(male gametophytes) (n)
2 Ovulate cone
bears ovules.
Mature sporophyte
Key
Haploid (n)
Diploid (2n)
Spore mother cell (2n)
Integument
3 Pollination
1 Sporangia produce
spores; spores develop
into pollen grains.
Scale
Sporangium (2n)
4 A haploid spore cell
Ovule
develops into female
gametophyte, which
makes eggs.
Meiosis
Meiosis
Pollen grains
(male gametophytes) (n)
2 Ovulate cone
bears ovules.
Mature sporophyte
Key
Haploid (n)
Diploid (2n)
Spore mother cell (2n)
Integument
3 Pollination
Egg (n)
Sperm (n)
Male gametophyte
(pollen grain)
5 Pollen grows
tube to egg
and makes
and releases
sperm.
Fertilization
Female
gametophyte (n)
1 Sporangia produce
spores; spores develop
into pollen grains.
Scale
Sporangium (2n)
4 A haploid spore cell
Ovule
develops into female
gametophyte, which
makes eggs.
tube to egg
and makes
and releases
sperm.
Meiosis
Meiosis
Pollen grains
(male gametophytes) (n)
Spore mother cell (2n)
Integument
3 Pollination
Egg (n)
2 Ovulate cone
bears ovules.
Fertilization
Sperm (n)
Male gametophyte
(pollen grain)
5 Pollen grows
Female
gametophyte (n)
Zygote
(2n)
Mature sporophyte
Seed coat
Seed
Embryo (2n)
Food supply
Key
Haploid (n)
Diploid (2n)
6 Zygote develops
into embryo, and
ovule becomes seed.
1 Sporangia produce
Scale
spores; spores develop
into pollen grains.
Sporangium (2n)
4 A haploid spore cell
Ovule
develops into female
gametophyte, which
makes eggs.
tube to egg
and makes
and releases
sperm.
Meiosis
Meiosis
Pollen grains
(male gametophytes) (n)
Spore mother cell (2n)
Integument
3 Pollination
Egg (n)
2 Ovulate cone
bears ovules.
Fertilization
Sperm (n)
Male gametophyte
(pollen grain)
5 Pollen grows
Female
gametophyte (n)
Zygote
(2n)
Mature sporophyte
Seed coat
Seed
Embryo (2n)
Food supply
Key
Haploid (n)
Diploid (2n)
6 Zygote develops
7 Seed germinates,
and embryo grows into seedling.
into embryo, and
ovule becomes seed.
17.7 A pine tree is a sporophyte with
gametophytes in its cones
 In pollination, a pollen grain lands on a scale in
an ovulate cone and enters an ovule
– The scales then grow together, sealing up the cone
– Within the sealed cone, the gametophytes produce
gametes
 Fertilization occurs a year after pollination, when
a sperm moves down a pollen tube to the egg to
form a zygote
– The zygote develops into a sporophyte embryo, and
the ovule becomes a seed, with stored food and a
protective seed coat
 The seed is a key adaptation for life on land and a
major factor in the success of seed plants
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17.8 The flower is the centerpiece of angiosperm
reproduction
Video: Flower Blooming (time lapse)
Copyright © 2009 Pearson Education, Inc.
17.8 The flower is the centerpiece of angiosperm
reproduction
 Flowers contain separate male and female
sporangia and gametophytes
 Flowers usually consist of sepals, petals, stamens
(which produce pollen), and carpels (which produce
eggs)
– Sepals enclose the flower before it opens
– Petals attract animal pollinators
 Stamens include a filament and anther, a sac at
the top of each filament that contains male
sporangia and releases pollen
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Stigma
Anther
Style
Carpel
Stamen
Ovary
Filament
Petal
Sepal
Ovule
Receptacle
17.8 The flower is the centerpiece of angiosperm
reproduction
 The carpel is the female reproductive structure,
including the ovary
– The ovary encloses the ovules, which contain
sporangia that will produce a female gametophyte
 Ovules develop into seeds; ovaries mature into
fruit
Copyright © 2009 Pearson Education, Inc.
17.9 The angiosperm plant is a sporophyte with
gametophytes in its flowers
 The angiosperm life cycle
1. Meiosis in the anthers produces haploid spores that
form the male gametophyte (pollen grains)
2. Meiosis in the ovule produces a haploid spore that
forms a tiny female gametophyte, including the egg
3. A pollen tube from the pollen grain to the ovule carries
a sperm that fertilizes the egg to form a zygote
4. Each ovule develops into a seed, consisting of an
embryo (a new sporophyte) with a food supply and a
seed coat
5. The ovary wall forms a fruit
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17.9 The angiosperm plant is a sporophyte with
gametophytes in its flowers
Animation: Plant Fertilization
Video: Flowering Plant Life Cycle (time lapse)
Animation: Seed Development
Copyright © 2009 Pearson Education, Inc.
1 Haploid spores in anthers develop into
pollen grains: male gametophytes.
Pollen grains (n)
Meiosis
2 Haploid spore in each ovule
develops into female gametophyte, which produces an egg.
Meiosis
Egg (n)
Ovule
Key
Haploid (n)
Diploid (2n)
1 Haploid spores in anthers develop into
pollen grains: male gametophytes.
Pollen grains (n)
3 Pollination and
growth of
pollen tube
Meiosis
Stigma
2 Haploid spore in each ovule
develops into female gametophyte, which produces an egg.
Pollen grain
Pollen tube
Meiosis
Egg (n)
Ovule
Sperm
Fertilization
Key
Haploid (n)
Diploid (2n)
1 Haploid spores in anthers develop into
pollen grains: male gametophytes.
Pollen grains (n)
3 Pollination and
growth of
pollen tube
Meiosis
Stigma
2 Haploid spore in each ovule
develops into female gametophyte, which produces an egg.
Pollen grain
Pollen tube
Meiosis
Egg (n)
Ovule
Sperm
Fertilization
Key
Haploid (n)
Diploid (2n)
4 Zygote
(2n)
1 Haploid spores in anthers develop into
pollen grains: male gametophytes.
Pollen grains (n)
3 Pollination and
growth of
pollen tube
Meiosis
Stigma
2 Haploid spore in each ovule
develops into female gametophyte, which produces an egg.
Pollen grain
Pollen tube
Meiosis
Egg (n)
Ovule
Sperm
Seeds
6 Fruit
Food supply
(mature
ovary)
Seed
coat
Fertilization
Key
Haploid (n)
Diploid (2n)
5 Seed
4 Zygote
Embryo (2n)
(2n)
1 Haploid spores in anthers develop into
pollen grains: male gametophytes.
Pollen grains (n)
3 Pollination and
growth of
pollen tube
Meiosis
Stigma
2 Haploid spore in each ovule
develops into female gametophyte, which produces an egg.
Stigma
Anther
Pollen grain
Pollen tube
Meiosis
Egg (n)
Ovule
Ovary
Sporophyte (2n)
Ovule
Sperm
7 Seed germinates,
and embryo
grows into
plant.
Seeds
6 Fruit
Food supply
(mature
ovary)
Seed
coat
Fertilization
Key
Haploid (n)
Diploid (2n)
5 Seed
4 Zygote
Embryo (2n)
(2n)
17.10 The structure of a fruit reflects its function
in seed dispersal
 Fruits, ripened ovaries of flowers, are adaptations
that disperse seeds
– Some rely on wind for seed dispersal
– Some hitch a ride on animals
– Fleshy, edible fruits attract animals
Animation: Fruit Development
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17.11 CONNECTION: Angiosperms sustain us—
and add spice to our diets
 Most human food is provided by the fruits and
seeds of angiosperms
– Corn, rice, wheat, and other grains are dry fruits
– Apples, cherries, tomatoes, and squash are fleshy
fruits
– Spices such as nutmeg, cinnamon, cumin, cloves,
ginger, and licorice are also angiosperm fruits
Copyright © 2009 Pearson Education, Inc.
17.12 EVOLUTION CONNECTION: Pollination
by animals has influenced angiosperm
evolution
 90% of angiosperms use animals to transfer pollen
– Birds are attracted by colorful flowers, but not scent
– Beetles are attracted by fruity odors, but not color
– Bats are attracted by large, highly scented flowers
– Wind-pollinated flowers produce large amounts of
pollen
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17.13 CONNECTION: Plant diversity is an
irreplaceable resource
 More than 50,000 square miles of forest are
cleared every year
– Replanted areas have greatly reduced biological
diversity
 Loss of forests has greatly reduced diversity of life
on Earth
– The loss of plant diversity removes potentially
beneficial medicines
– More than 25% of prescription drugs are extracted
from plants
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Leaves carry out photosynthesis
Reproductive structures, as in flowers,
contain spores and gametes
Cuticle covering leaves and stems
reduces water loss
Stomata in leaves allow gas exchange
between plant and atmosphere
Lignin hardens cell walls of some
plant tissues
Stem supports plant; may perform
photosynthesis
Vascular tissues in shoots and roots
transport water, minerals, and sugars;
provide support
Roots anchor plant; mycorrhizae (rootfungus associations) help absorb water
and minerals from the soil
ANCESTRAL
GREEN ALGA
1
a.
b.
2
c.
3
d.
A. Pine tree, a gymnosperm
B. Puffball, a club fungus
You should now be able to
1. Describe the key plant adaptations for life on land
2. Describe the alternation of generation life cycle;
explain why it appears that this cycle has evolved
independently in algae and land plants
3. Describe the key events of the moss, fern, and
pine life cycles
4. Explain how coal was formed; explain why coal,
oil, and natural gas are called fossil fuels
Copyright © 2009 Pearson Education, Inc.
You should now be able to
5. Describe the parts of a flower and explain their
functions
6. Describe the stages of the angiosperm life cycle
7. Describe angiosperm adaptations that promote
seed dispersal
8. Explain how flowers are adapted to attract
pollinators
9. Compare the life cycles and reproductive
structures in the fungal groups
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You should now be able to
10. Describe the structure and characteristics of
lichens
11. Describe the positive ecological and practical
roles of fungi
Copyright © 2009 Pearson Education, Inc.