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LECTURE PRESENTATIONS
For CAMPBELL BIOLOGY, NINTH EDITION
Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson
Chapter 29
Plant Diversity I: How Plants
Colonized Land
Lectures by
Erin Barley
Kathleen Fitzpatrick
© 2011 Pearson Education, Inc.
Overview: The Greening of Earth
• First 3 billion years: terrestrial surface was
lifeless
• 1.2 byo: Cyanobacteria
• 500 myo: small plants, fungi, and animals
emerged on land
• ~ 290,000 living species of plants
• Land plants: terrestrial ancestors, though some
are now aquatic
– Does not include photosynthetic protists (algae)
– supply oxygen and source of most food eaten by land
animals
© 2011 Pearson Education, Inc.
Figure 29.1
1 m
Concept 29.1: Land plants evolved from
green algae
• Green algae (charophytes) are the closest
relatives of land plants
– both nuclear and chloroplast genes
• land plants share 4 traits with only charophytes
–
–
–
–
Rings of cellulose-synthesizing complexes
Peroxisome enzymes
Structure of flagellated sperm
Formation of a phragmoplast
© 2011 Pearson Education, Inc.
Figure 29.3
5 mm
Chara species, a pond organism
Coleochaete orbicularis, a
disk-shaped charophyte
that also lives in ponds (LM)
40 m
1 m
Adaptations Enabling the Move to Land
• Charophytes: sporopollenin layer prevents
exposed zygotes from drying out
– Also in plant spore walls
• Moving to land
– Pros: provided unfiltered sun, more plentiful CO2,
nutrient-rich soil, and few herbivores or pathogens
– Cons: scarcity of water and lack of structural support
© 2011 Pearson Education, Inc.
Derived Traits of Plants
– Alternation of generations and multicellular,
dependent embryos
• Haploid gametophyte  haploid gametes (mitosis)
• Fusion of the gametes  diploid sporophyte  haploid spores
(meiosis)
– Walled spores produced in sporangia
• sporophyte  spores in sporangia
• diploid sporocytes (meiosis)  haploid spores
• Spore walls contain sporopollenin, which makes them resistant
to harsh environments
© 2011 Pearson Education, Inc.
Figure 29.5c
Spores
Sporangium
Longitudinal section of
Sphagnum sporangium (LM)
Sporophyte
Gametophyte
1 m
Sporophytes and sporangia of Sphagnum (a moss)
Derived Traits of Plants
– Multicellular gametangia
• Gametes are produced in gametangia
• Female gametangia (archegonia)  eggs (site of
fertilization)
• Male gametangia (antheridia)  sperm (pollen)
– Apical meristems
• Plants sustain continual growth
• Cells differentiation
• Additional derived traits include
 Cuticle: waxy covering
 Mycorrhizae: fungi and land plants symbiosis
 Secondary compounds deter herbivores and parasites
© 2011 Pearson Education, Inc.
Figure 29.5d
Female
gametophyte
Archegonia,
each with an
egg (yellow)
Antheridia
(brown),
containing
sperm
Male
gametophyte
Archegonia and antheridia of Marchantia (a liverwort)
1 m
Figure 29.5e
Apical meristem
of shoot
Developing
leaves
Apical meristems of plant
roots and shoots
Apical
meristem
of root
Root
100 m
Shoot
1 m
100 m
The Origin and Diversification of Plants
• Fossil evidence: plants on land 475 myo
– grouped on presence of vascular tissue
– Bryophytes: nonvascular plants
• Seedless vascular plants
• Lycophytes (club mosses)
– Pterophytes (ferns)
• Seed Plants
– Gymnosperms: conifers, naked seed
– Angiosperms: flowering plants
© 2011 Pearson Education, Inc.
Figure 29.7
1 Origin of land plants (about 475 mya)
2 Origin of vascular plants (about 425 mya)
3 Origin of extant seed plants (about 305 mya)
Mosses
Land plants
ANCESTRAL
1
GREEN
ALGA
Nonvascular
plants
(bryophytes)
Liverworts
Hornworts
Pterophytes (ferns,
horsetails, whisk ferns)
3
Angiosperms
500
450
400
350
300
Millions of years ago (mya)
50
0
1 m
Seed plants
Gymnosperms
Vascular plants
2
Seedless
vascular
plants
Lycophytes (club
mosses, spike
mosses, quillworts)
Concept 29.2: Mosses and other nonvascular plants have life cycles
dominated by gametophytes
Concept 29.3: Ferns and other seedless vascular plants were the
first plants to grow tall
 Life cycles with dominant sporophytes
 Vascular tissues: xylem and phloem
 allowed for increased height  evolutionary advantage
 Well-developed roots and leaves
• Increased height and photosynthesis removed CO2 from the
atmosphere  contributed to global cooling
• The decaying plants of these forests eventually became coal
© 2011 Pearson Education, Inc.
Figure 29.9c
Polytrichum commune,
hairy-cap moss
Capsule
Seta
Sporophyte
(a sturdy
plant that
takes months
to grow)
Gametophyte
1 m
Plant Parts
• Xylem: water and minerals and includes dead cells
called tracheids
– Lignin: provide structural support
• Phloem: living cells and distributes sugars, amino
acids, and other organic products
• Roots: anchors
– absorb water and nutrients from the soil
• Leaves: increase the surface area  solar energy
for photosynthesis
 Microphylls: single vein
 Megaphylls: highly branched
© 2011 Pearson Education, Inc.
Figure 29.15b
Equisetum arvense,
field horsetail
Athyrium
filix-femina,
lady fern
Vegetative stem
1.5 cm
25 cm
Strobilus on
fertile stem
4 cm
Psilotum
nudum,
a whisk
fern
1 m
LECTURE PRESENTATIONS
For CAMPBELL BIOLOGY, NINTH EDITION
Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson
Chapter 30
Plant Diversity II: The Evolution
of Seed Plants
Lectures by
Erin Barley
Kathleen Fitzpatrick
© 2011 Pearson Education, Inc.
Overview: Transforming the World
• 360 myo: seed plants
• Seeds & pollen grains are key adaptations for life on land
– The gametophytes develop within the walls of spores
– Heterospory:
• Megasporangia: female gametophytes (ovule)
• Microsporangia: male gametophytes (pollen)
– Ovule:
• Gymnosperm: one integument
• Angiosperm: two integuments
• Pollination: pollen transferred to ovules
© 2011 Pearson Education, Inc.
The Evolutionary Advantage of Seeds
• A seed: sporophyte embryo, along with its food supply,
packaged in a protective coat; the whole ovule
• evolutionary advantages
– dormant for days to years until favorable conditions
germination
– stored food
– transported long distances by wind or animals
• Gymnosperms: seeds are exposed on sporophylls that form
cones
• Angiosperm: seeds are found in fruits, which are mature
ovaries
– most widespread and diverse of all plants
© 2011 Pearson Education, Inc.
Figure 30.3-3
Immature
ovulate cone
Female
gametophyte (n)
Integument (2n)
Spore wall
Micropyle
Pollen grain (n)
(a) Unfertilized ovule
Spore
wall
Egg nucleus
(n)
Megaspore (n)
Megasporangium
(2n)
Seed
coat
Discharged
sperm nucleus
(n)
Pollen tube
Male gametophyte (n)
(b) Fertilized ovule
Food
supply (n)
Embryo (2n)
(c) Gymnosperm seed
Figure 30.5e
Common juniper
Douglas fir
Sequoia
European larch
Wollemi pine
Bristlecone pine
Angiosperms
• cross-pollination: different plants of same species
• Flower: sexual reproduction
– pollinated by insects, animals, or wind
• modified leaves
– Sepals: enclose the flower, green bud
– Petals: brightly colored to attract pollinators
– Stamens: produce pollen, male
• filament (stalk) with anther that produces pollen
– Carpels: produce ovules, female
• ovary (base), style (stalk), & stigma (receives pollen)
© 2011 Pearson Education, Inc.
Figure 30.7
Stigma
Stamen
Anther
Carpel
Style
Filament
Ovary
Petal
Sepal
Ovule
Fruits
• A fruit typically consists of a mature ovary but
can also include other flower parts
• Fruits protect seeds and aid in their dispersal
• Mature fruits can be either fleshy or dry
Animation: Fruit Development
© 2011 Pearson Education, Inc.
Figure 30.8
Tomato
Ruby grapefruit
Nectarine
Hazelnut
Milkweed
Figure 30.9
Wings
Seeds within berries
Barbs
• Double fertilization: pollen tube discharges two
sperm into an ovule
– One sperm fertilizes the egg
– other combines with two nuclei in the central cell of the
female gametophyte and initiates development of foodstoring endosperm
• nourishes the developing embryo
• Within a seed, the embryo consists of a root and
two seed leaves called cotyledons
– Monocots (one cotyledon)
– Dicots (two dicots)
© 2011 Pearson Education, Inc.
Figure 30.10-4
Mature flower on
sporophyte plant
(2n)
Microsporangium
Anther
Microsporocytes (2n)
MEIOSIS
Ovule (2n)
Ovary
Germinating
seed
MEIOSIS
Generative cell
Male
gametophyte
(in pollen
grain) (n)
Pollen
tube
Embryo (2n)
Surviving
megaspore
(n)
Endosperm (3n) Seed
Seed coat (2n)
Nucleus of
developing
endosperm
(3n)
Zygote (2n)
Antipodal cells
Central cell
Synergids
Egg (n)
Egg
nucleus (n)
Style
Pollen
tube
Sperm
(n)
FERTILIZATION
Key
Haploid (n)
Diploid (2n)
Tube cell
Pollen
grains
Stigma
Megasporangium (2n)
Female
gametophyte
(embryo sac)
Microspore (n)
Discharged sperm nuclei (n)
Sperm
Figure 30.13c
Monocots
Orchid
Lily
Pygmy date palm
Anther
Stigma
Filament
Barley, a grass
Ovary
Figure 30.13ea
Monocot
Characteristics
Eudicot
Characteristics
Embryos
Two cotyledons
One cotyledon
Leaf
venation
Veins usually
netlike
Veins usually
parallel
Stems
Vascular tissue
scattered
Vascular tissue
usually arranged
in ring
Figure 30.13eb
Monocot
Characteristics
Eudicot
Characteristics
Roots
Taproot (main root)
usually present
Root system
usually fibrous
(no main root)
Pollen
Pollen grain with
one opening
Pollen grain with
three openings
Flowers
Floral organs
usually in
multiples of three
Floral organs
usually in multiples
of four or five
• Seed Plants are key sources of food, fuel,
wood products, and medicine
– Six crops (wheat, rice, maize, potatoes,
cassava, and sweet potatoes) yield 80% of
the calories consumed by humans
© 2011 Pearson Education, Inc.
Threats to Plant Diversity
• Destruction of habitat is causing extinction of
many plant species and is accompanied by loss
of the animal species
• At the current rate of habitat loss, 50% of Earth’s
species will become extinct within the next 100–
200 years
© 2011 Pearson Education, Inc.
Figure 30.16
A satellite image
from 2000 shows
clear-cut areas in
Brazil surrounded
by dense tropical
forest.
4 km
By 2009, much
more of this same
tropical forest had
been cut down.
LECTURE PRESENTATIONS
For CAMPBELL BIOLOGY, NINTH EDITION
Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson
Chapter 31
Fungi
Lectures by
Erin Barley
Kathleen Fitzpatrick
© 2011 Pearson Education, Inc.
Overview: Mighty Mushrooms
• Fungi break down organic material and recycle
vital nutrients
• Fungi are heterotrophs that feed by absorption
– enzymes break down complex molecules into smaller
organic compounds
– Decomposers
– Parasites
– Mutualists
© 2011 Pearson Education, Inc.
Body Structure
• Yeast: most common body structures are multicellular
filaments and single cells
• Mycelia: networks of branched hyphae adapted for
absorption
– High surface area-to-volume ratio
• Chitin: in cell walls
• Septa: divided hyphae into cells with pores for cell-to-cell
movement of organelles
© 2011 Pearson Education, Inc.
Figure 31.2
Reproductive structure
Hyphae
Spore-producing
structures
60 m
Mycelium
Specialized Fungi
• Haustoria: specialized
hyphae allow them to
penetrate the tissues
of their host
• Mycorrhizae:
symbiosis between
fungi and plant roots
© 2011 Pearson Education, Inc.
Concept 31.2: Fungi produce spores
through sexual or asexual life cycles
• Sexual reproduction requires the fusion of hyphae
from different mating types
• Asexually reproduction:
– mold: produce haploid spores by mitosis and form
visible mycelia
– Yeast: cell division and the pinching of “bud cells” from
a parent cell
– Deuteromycetes: no sexual stage, or imperfect fungi
© 2011 Pearson Education, Inc.
Figure 31.5-3
Key
Haploid (n)
PLASMOGAMY
Heterokaryotic
Heterokaryotic
stage
Diploid (2n)
Spore-producing
structures
KARYOGAMY
Spores
Mycelium
ASEXUAL
REPRODUCTION
GERMINATION
SEXUAL
REPRODUCTION
Zygote
GERMINATION
MEIOSIS
Spores
Figure 31.6
1.5 m
Figure 31.7
10 m
Parent
cell
Bud
Concept 31.3: The ancestor of fungi was
an aquatic, single-celled, flagellated protist
• Fungi and animals are more closely related to
each other than they are to plants or other
eukaryotes
© 2011 Pearson Education, Inc.
Figure 31.11
Hyphae
25 m
Fungal hypha
25 m
Chytrids (1,000 species)
Zygomycetes (1,000 species)
Glomeromycetes (160 species)
Ascomycetes (65,000 species)
Basidiomycetes (30,000 species)
Types of Fungi
• Chytrids
– freshwater and terrestrial habitats
– Zoospores: flagellated spores
• Zygomycota: fast-growing molds, parasites, and
commensal symbionts; black bread mold
• Ascomycota: Asci: sexual spores
– sac fungi
– yeasts to elaborate cup fungi and morels
• Basidiomycota: mushrooms, puffballs, and shelf fungi,
mycorrhizae, and plant parasites
– club fungi
– decomposers of wood
© 2011 Pearson Education, Inc.
Figure 31.14
0.5 mm
Figure 31.16
Morchella esculenta,
the tasty morel
Tuber melanosporum, a truffle
Figure 31.18
Shelf fungi
Puffballs emitting
spores
Maiden veil fungus
(Dictyphora)
Figure 31.20
Symbiosis
• Fungi: efficient decomposers of organic material
• essential recycling of chemical elements between
the living and nonliving world
• Fungi form mutualistic relationships
• Plants harbor harmless endophytes that make toxins
that deter herbivores and defend against pathogens
• break down plant material in the guts of cows and
other grazing mammals
• Many species of ants use the digestive power of fungi
by raising them in “farms”
• Lichen: photosynthetic microorganism (algae or
cyanobacteria) and a fungus
© 2011 Pearson Education, Inc.
Figure 31.22
Figure 31.23
A foliose
(leaflike) lichen
Crustose
(encrusting) lichens
A fruticose (shrublike) lichen
Figure 31.24
Ascocarp of fungus
50 m
Fungal
hyphae Algal
layer
Fungal hyphae
Algal cell
Soredia
Fungi as Pathogens
• About 30% fungal species are parasites or
pathogens, mostly on or in plants
• 10%-50% of the world’s fruit harvest is lost due to
fungi each year
• Some food crop fungi are toxic to humans
– Ergots contain lysergic acid, the raw material for LSD
– Ergotism: gangrene, nervous spasms, burning sensations,
hallucinations, and temporary insanity
• mycosis: fungal infection in animals
– Ringworm and athlete’s foot
– Candida albicans: yeast infections
© 2011 Pearson Education, Inc.
Figure 31.25
(b) Tar spot
fungus
on maple
leaves
(a) Corn smut on corn
(c) Ergots on rye
Practical Uses of Fungi
• Humans eat many fungi and use others to
make cheeses, alcoholic beverages, and
bread
• Some fungi are used to produce antibiotics
for the treatment of bacterial infections
– ascomycete Penicillium
© 2011 Pearson Education, Inc.
Figure 31.27
Staphylococcus
Penicillium
Zone of
inhibited
growth