BIOLOGY
Chapter 23: pp. 408 - 432
10th Edition
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seed cones
seed cones
pollen cones
a. A northern coniferous forest of evergreen trees
b. Cones of lodgepole pine, Pinus contorta
Sylvia S. Mader
Plant Evolution and
Diversity
c. Fleshy seed cones of juniper, Juniperus
a: © Corbis Royalty Free; b: © Walt Anderson/Visuals Unlimited; c: © The McGraw Hill Companies, Inc./Evelyn Jo Johnson, photographer
PowerPoint® Lecture Slides are prepared by Dr. Isaac Barjis, Biology Instructor
Copyright © The McGraw Hill Companies Inc. Permission required for reproduction or display
1
Outline

Evolutionary History
The Green Algal Ancestor
 Alternation of Generations

Nonvascular Plants
 Vascular Plants

Seedless
 Seed
 Angiosperms

Monocots and Eudicots
 Flowers

2
Evolutionary History of Plants
Plants are multicellular, photosynthetic
eukaryotes.
 Plants evolution is marked by adaptations
to a land existence.
 A land environment does offer certain
advantages.

Plentiful light for photosynthesis
 Carbon dioxide is present in higher
concentrations and diffuses more readily in air
than in water.

3
Evolutionary History of Plants

A land environment does offer certain
advantages

Constant threat of desiccation (drying out).
Protect all phases of reproduction (sperm, egg,
embryo) from drying out
 Seed plants disperse their embryos within the seed,
which provides the embryo with food within a
protective seed coat.


The water environment provides
plentiful water.
 support for the body of the plant.

4
Evolutionary History of Plants

To conserve water, the land plant body, is covered by a
waxy cuticle.

Impervious to water while still allowing carbon dioxide to enter so
that photosynthesis can continue

Vascular system transports water in the body of the land
plant.

Thought to have evolved from freshwater green algae
over 450 mya

Evolution of plants marked by four evolutionary events
associated with four major groups of plants

Nonvascular Plants

Advent of nourishment of a multicellular embryo within the body
of the female plant
5
Evolutionary History of Plants

Seedless vascular plants


Gymnosperms and angiosperms


Advent of vascular tissue
Produce seeds
Flowering Plants

Attract pollinators that give rise to fruits
6
Evolutionary History of Plants
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flowers, double fertilization, endosperm, fruit
common ancestor
Flowering plants
Seed
seeds
megaphylls
Vascular
Gymnosperms
vascular
tissue
apical
growth
Seedless
Ferns and allies
microphylls
embryo
protection
Bryophytes
Mosses
Hornworts
common
green
algal
ancestor
Liverworts
Nonvascular
Lycophytes
Charophytes
550
500
450
400
350
Million Years Ago (MYA)
300
250
PRESENT
7
Close Algal Relatives of Land Plant
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Chara
Coleochaete
(Coleochaete): © T. Mellichamp/Visuals Unlimited; (Chara): © Heather Angel/Natural Visions © INTERFOTO Pressebildagentur
8
Alternation of Generations

Life cycle involves alternation of generations



1n individuals (gametophytes) produce
2n individuals (sporophytes)
2n individuals (sporophytes) produce
1n individuals (gametophytes)
Sporophyte (2n):



Multicellular
multicellular
Multicellular
multicellular
Multicellular individual that produces spores by meiosis
Spore is haploid cell that will become the gametophyte
Gametophyte (1n):



Multicellular individual that produces gametes
Gametes fuse in fertilization to form zygote
Zygote is a diploid cell that will become the sporophyte
9
Alternation of Generations
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sporophyte
(2n)
sporangium (2n)
zygote (2n)
diploid (2n)
MEIOSIS
FERTILIZATION
haploid (n)
spore (n)
(n)
(n)
gametes
gametophyte
(n)
10
Alternation of Generations

Appearance of generations varies widely

In ferns, female portions are archegonia and are
fertilized by flagellated sperm

In angiosperm, female gametophyte (embryo sac),
consists of an ovule


Following fertilization, ovule becomes seed
In seed plants, pollen grains are mature sperm-bearing
male gametophytes
11
Reduction in the Size of the Gametophyte
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spores
G
a
m
e
t
o
p
h
y
t
e
seed
seed
spores
roots
roots
rhizoids
roots
rhizoids
(n)
Moss
Fern
S
p
o
r
o
p
h
y
t
e
(2n)
Gymnosperm
Angiosperm
12
Other Terrestrial Adaptations

Vascular tissue transports water and
nutrients to the body of the plant

Cuticle provides an effective barrier to
water loss

Stomata bordered by guard cells that
regulate opening, and thus water loss
13
Leaf Adaptation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
cuticle
a. Stained photomicrograph
of a leaf cross section
Plant leaves have a
Cuticle and stomata
Stomata
400 x
b. Falsely coloured scanning
Electron micrograph of leaf
surface
(Left): © Kingsley Stern; (Right): © Andrew Syred/SPL /Photo Researchers, Inc.
14
Nonvascular Plants: Bryophytes

Nonvascular plants (bryophytes)

Lack specialized means of transporting water and
organic nutrients

Do not have true roots, stems, and leaves

Gametophyte is dominant generation

Produces eggs in archegonia

Produces flagellated sperm in antheridia

Sperm swim to egg in film of water to make zygote
15
Nonvascular Plants

Hornworts (phlym Anthocerophyta) have small
sporophytes that carry on photosynthesis

Liverworts (phylum Hepatophyta) have either
flattened thallus or leafy appearance

Mosses (phylum Bryophyta) usually have a leafy
shoot, although some are secondarily flattened

Can reproduce asexually by fragmentation

Dependent sporophyte consists of foot, stalk, and
sporangium
16
Hornwort
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
sporophyte
gametophyte
B. Runk/S. Schoenberger/Grant Heilman Photography
17
Liverwort, Marchantia
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
male gametophyte
female gametophyte
gemma cup
thallus
rhizoids
gemma
a. Thallus with gemmae cups
b. Male gametophytes bear
antheridia
c. Female gametophytes bear
archegonia
a: © Ed Reschke/Peter Arnold, Inc.; b: © J.M. Conrarder/National Audubon Society/Photo Researchers, Inc.; c: © R. Calentine/Visuals Unlimited
18
Moss (Polytrichum) Life Cycle
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4. The sporophyte:
The mature sporophyte has a foot buried in female
gametophyte tissue, a stalk, and an upper capsule (the
sporangium), where meiosis occurs and spores are
developing
sporophyte
3. The zygote:
The zygote and
developing
sporophyte are
retained within
the archegonium.
capsule
5. The spores:
When the calyptra
and lid (operculum) of
a capsule fall off, the
spores are mature.
One or two rings of
teeth project inward
from the margin of
teeth
the capsule. The
operculum
teeth close the
opening, except when
the weather is dry.
Sporangium
calyptra
Mitosis
stalk
Sporophyte
zygote
diploid (2n)
MEIOSIS
FERTILIZATION
haploid (n)
2. Fertilization:
Flagellated sperm
produced in
antheridia swim in
external water to
archegonia, each
bearing a single
egg.
sperm
Spores
foot (n)
egg
Mitosis
Archegonia
6. Spore dispersal:
Spores are released
when they are most
likely to be dispersed
by air currents.
buds
Protonema
Antheridia
1. The mature
gametophytes:
In mosses, the leafy
gametophyte shoots
bear either
antheridia
or archegonia,
where
gametes are
7. The immature
gametophyte:
A spore germinates
into a male or female
protonema, the first
stage of the male
and the female
gametophytes.
Gametophytes
rhizoids
(Top): © Heather Angel/Natural Visions; (Bottom): © Bruce Iverson
19
Vascular Plants





Dominate the natural landscape
Xylem conducts water and dissolved minerals up
from roots
Phloem conducts sucrose and other organic
compounds throughout the plant
Lignin strengthens walls of conducting cells in
xylem
Most seedless vascular plants are homosporous


Windblown spores are dispersal agents
All seed plants are heterosporous and have male
and female gametophytes

Seeds disperse offspring
20
Seedless Vascular Plants: Lycophyta

Club Mosses (phylum Lycophyta)

Typically, branching rhizome sends up short aerial
stems

Leaves are microphylls (have only one strand of
vascular tissue)

Most likely evolved as simple side extensions of the
stem

Sporangia occur on surfaces of sporophylls

Grouped into club-shaped strobili
21
Seedless Vascular Plants
Roots evolved simply as lower extensions of
the stem
 Today’s lycophytes, also called club mosses,
include three groups of 1,150 species:

Ground pines (Lycopodium),
 Spike mosses (Selaginella), and
 Quillworts (Isoetes)

22
Ground Pine
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
sporangia
strobili
leaves
(microphylls)
sporophyll
Strobilus
stoma
branches
vascular tissue
Leaf
xylem
phloem
arial stem
rhizome
root
Root
23
Cooksonian Fossil
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
sporangia
Courtesy Hans Steur, the Netherlands
24
Seedless Vascular Plants: Pteridophytes

Includes Ferns and their Allies (horsetails and
whisk ferns)

Have megaphylls (broad leaves)

Allow plants to efficiently collect solar energy,


Produce more food and the possibility of producing more
offspring than plants without megaphylls.
Horsetails

Rhizome produces tall aerial stems

Contains whorls of slender, green branches

Small, scalelike leaves also form whorls at the joints
25
Horsetail, Equisetum
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
strobilus
branches
node
leaves
rhizome
root
© Robert P. Carr/Bruce Coleman, Inc.
26
Microphylls and Megaphylls
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single strand of
vascular tissue
a. Microphyll
branched
vascular tissue
Megaphyll
One branch began to
dominate the stem system.
branched
stem system
The side branches flattened
into a single plane.
Tissue filled in the spaces
between the side branches.
megaphyll
leaf
b. Megaphyll evolution process
27
Ferns

Whisk Ferns (phylum Psilotophyta)
Branched rhizome has rhizoids
 Mutualistic mycorrhizal fungus helps gather
nutrients


Ferns (phylum Pterophyta)

Large conspicuous fronds
Divided into leaflets
 Dominant sporophyte produces windblown spores

28
Whisk fern, Psilotum
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
sporangium
scale
aerial stem
root
rhizome
© CABISCO/Phototake
29
Diversity of Ferns
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spores on
fertile frond
stipe
Cinnamon fern, Osmunda cinnamomea
frond
(undivided)
frond
(divided)
axis
leaflet
Hart's tongue fern,
Campyloneurum scolopendrium
Maidenhair fern,
Adiantum pedatum
© CABISCO/Phototake
30
Fern Life Cycle
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
7. The fronds:
The sporophyte
develops a rootbearing rhizome
from which the
aerial fronds
project.
sori
1. The sporophyte:
The sporophyte is
dominant in ferns.
Sporophyte
Dryopterus
6. The zygote:
The resulting
sporophyte zygote
begins its
development inside
an archegonium.
As the distinctive
first leaf appears
above the
prothallus, and
as the roots
develop below it,
the sporophyte
becomes visible.
leaflet
sporangium
Sorus
young sporophyte
on gametophyte
fiddlehead
rhizome
2. The sporangia:
In this fern, the
sporangia are
located within
sori (sing., sorus),
on the underside of
roots
Mitosis
annulus
zygote
Sporangium
diploid (2n)
MEIOSIS
FERTILIZATION
haploid (n)
5. Fertilization:
Fertilization takes
place when
moisture is
present, because
the flagellated
sperm must swim
in a film of water
from the
antheridia to the
egg within
egg
sperm
Spores
Archegonium
prothallus
(underside)
Mitosis
3. The spores:
Within a
sporangium,
meiosis occurs
and spores are
produced. When a
sporangium opens,
the spores are
germinating
spore
Antheridium
Gametophyte
rhizoids
4. The gametophyte:
A spore germinates into a
prothallus (the gametophyte),
which typically bears
archegonia at
the notch and antheridia at the
© Matt Meadows/Peter Arnold, Inc.
31
The Uses of Ferns
Edible ferns are used as a food source
 Harbor nitrogen-fixing cyanobacteria
 Azolla is grown in rice paddies, where it
fertilizes rice plants.
 Ferns and their allies are used as
medicines in China.
 Extracts from ferns have also been used to
kill insects
 Used as decoration

32
Seed Plants

Seed plants are the most plentiful plants in
the biosphere

Seed coat and stored food allow an embryo to
survive harsh conditions during long period of
dormancy

Heterosporous

Drought-resistant pollen grains

Ovule develops into seed
33
Seed Plants
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seed cones
seed cones
pollen cones
a. A northern coniferous forest of evergreen trees
b. Cones of lodgepole pine, Pinus contorta
c. Fleshy seed cones of juniper, Juniperus
a: © Corbis Royalty Free; b: © Walt Anderson/Visuals Unlimited; c: © The McGraw Hill Companies, Inc./Evelyn Jo Johnson, photographer
34
Gymnosperms

Gymnosperms have ovules and seeds
exposed on the surface of sporophylls

Conifers

Cycads

Ginkgoes

Gnetophytes
35
Conifers

Conifers, as well as other gymnosperm
phyla, bear cones

Tough, needlelike leaves of pines conserve
water with a thick cuticle and recessed stomata

Considered a “soft” wood because it consists
primarily of xylem tissue
36
Pine Life Cycle
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1. The pollen cones:
Typicall y , the pollen
cones are quite small
and develop near the
tips of lower
branches.
7. The sporophyte:
After fertilization, the
ovule matures and
becomes the seed
composed of the
embryo, reserve
food, and a seed
coat. Finally, in the
fall of the second
season, the seed
cone, by now woody
and hard, opens to
release winged
seeds. When a
seed germinates,
the sporophyte
embryo develops
The seed cones:
The seed cones are larger
than the pollen cones and
are located near the tips
of higher branches.
2. The pollen sacs:
A pollen cone has two
pollen sacs
(microsporangia) that
lie on the underside of
each scale.
Sporophyte
seed
wing
pollen cones
seed cone
Pollen sac
(microsporangium)
Ovule
(megasporangium)
embryo
seed coat
stored food
pollen cone scale
The ovules:
The seed cone has two
ovules
(megasporangia) that
lie on the upper
seed cone scale
seed
mitosis
3. The microspores:
Within the pollen sacs,
meiosis produces four
microspores.
zygote
microspore
mother cell
6. The zygote:
diploid (2n)
Once a pollen grain
FERTILIZATION
reaches a seed cone,
haploid (n)
it becomes a mature
Pollen grain
male gametophyte.
Mature female gametophyte
A pollen tube digests
archegonium
its way slowly toward
a female gametophyte
ovule
and discharges two
wall
Pollination
nonflagellated sperm.
One of these
fertilizes an egg in
mitosis
Mature male gametophyte
an archegonium, and
a zygote results.
pollen tube
megaspore
mother cell
MEIOSIS
MEIOSIS
Microspores
Mitosis
Megaspore
ovule
wall
pollen grain
sperm
5. The mature female gametophyte:
Only one of the megaspores undergoes mitosis
and develops into a mature female gametophyte,
having two to six archegonia. Each archegonium
contains a single large egg lying near
the ovule opening.
The megaspore:
W ithin an ovule,
meiosis produces
four megaspores,
only one survives.
4. The pollen grains:
Each microspore
becomes a pollen
grain, which has two
wings and is carried by
the wind to the seed
cone during pollination.
200 µm
37
The Uses of Pine

Used in construction of all sorts.


Although technically a softwood, some pinewoods are
actually harder than so-called hardwoods.
The foundations of the Brooklyn Bridge are made of
Southern yellow pine.

Used for parks and gardens, and Christmas
decorations.
 Pine needles are rich in vitamins A and C.


Used as a medicine
Pine oil is distilled from the twigs and needles of
Scotch pines and used to scent a number of
household and personal care products
38
Cycads

Cycads (phylum Cycadophyta)

Large, finely divided leaves that grow in
clusters at the top of the stem

Pollen and seed cones on separate plants

Pollinated by insects
39
Ginkgoes

Ginkgoes (phylum Ginkgophyta)

Dioecious


Some trees producing seeds

Others producing pollen
One surviving species (Gingko biloba)
40
The Ginkgo Tree
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
ovule
seed
b. Ginkgo biloba, a native of China
b(Main): © Runk/Schoenburger/Grant Heilman Photography; b(Inset): Courtesy Ken Robertson, University of Illinois/INHS
41
Ephedra
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
leaves
microsporangia
c. Ephedra, a type of genetophyte
c(Main): © Daniel L. Nickrent; c(Inset): Courtesy K.J. Niklas
42
Welwitschia miribilis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
pollen cones
leaf
d. Welwitschia mirabilis, a type of gnetophyte
© NHPA/Steve Robinson
43
Gnetophytes

Gnetophytes (phylum Gnetophyta)

Have similarly structured xylem

None have archegonia

Strobili have similar construction
44
Angiosperms

Angiosperms (phylum Anthophyta)

An exceptionally large and successful group of
plants

Ovules are always enclosed within diploid tissues

Became dominant group of plants in the late
Cretaceous and early Paleocene periods
45
Amborella trichopoda
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Courtesy Stephen McCabe/Arboretum at University of California Santa Cruz
46
Monocots and Eudicots

Two classes of flowering plants

Monocotyledones (Monocots)


One cotyledon in seed
Eudicotyledones (Dicots)

Two cotyledons in seed
47
Flower Diversity
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Beavertail cactus,
Opuntia basilaris
Snow trillium, Trillium nivale
Water lily, Nymphaea odorata
Apple blossom, Malus domestica
Blue flag iris, Iris versicolor
Butterfly weed, Asclepias tuberosa
(Cactus): © Christi Carter/Grant Heilman Photography; (Butterfly weed): © Evelyn Jo Johnson; (Water lily): © Pat Pendarvis; (Iris): © David Cavagnaro/Peter Arnold, Inc.; (Trillium): © Adam Jones/Photo Researchers, Inc.; (Apple blossoms): © Inga Spence/Photo
Researchers, Inc.
48
The Flower

Peduncle (flower stalk) expands at tip into
a receptacle

Bears sepals, petals, stamens, and carpels, all
attached to receptacle in whorls

Calyx (collection of sepals) protect flower bud
before it opens

Corolla (collection of petals)
49
The Flower

Each stamen consists of an anther and a
filament (stalk)

Carpel has three major regions

Ovary - Swollen base

Fruit

Style - Elevates stigma

Stigma - Sticky receptor of pollen grains
50
Generalized Flower
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
anther
stigma
filament
style
pollen
tube
ovary
stamens
ovule
carpel
receptacle
petals (corolla)
sepals (calyx)
51
Flowering Plant Life Cycle
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Stamen
Carpel
stigma
anther
style
filament
ovary
ovule
7. The sporophyte:
The embryo within a seed
is the immature sporophyte.
When a seed germinates,
growth and differentiation
produce the mature
sporophyte of a flowering plant.
The ovules:
In an ovule (megasporangium)
within an ovary, meiosis
produces four megaspores.
Mitosis
stigma
fruit
(mature ovary)
Sporophyte
1. The stamen:
An anther at the top of a stamen
has four pollen sacs. Pollen
grains are produced in pollen
seed
(mature ovule)
6. The seed:
The ovule now develops
into the seed, which
contains an embryo and
food enclosed by a
protective seed coat. The
wall of the ovary and
sometimes adjacent parts
develop into a fruit that
2. The pollen sacs:
In pollen sacs
(microsporangia) of the
anthe ,rmeiosis produces
microspores.
The carpel:
The ovary at the base of a carpel
contains one or more ovules. The
contents of an ovule change
during the flowering plant life
cycle.
seed coat
embryo
Pollen sac
(microsporangium)
Ovule
(megasporangium)
style
ovary
Anther
endosperm (3n)
Seed
diploid (2n)
FERTILIZATION
MEIOSIS
haploid (n)
MEIOSIS
Pollen grain
(Mature male gametophyte)
5. Double fertilization:
On reaching the ovule, the
pollen tube discharges the
sperm. One of the two
sperm migrates to and
fertilizes the egg, forming
a zygote; the other unites
with the two polar nuclei,
producing a 3n (triploid)
endosperm nucleus. The
endosperm nucleus
divides to form
tube cell
Pollination
generative cell
ovule wall
polar nuclei
sperm
pollen
tube
sperm
Microspores
Megaspores
ovule wall
antipodals
egg
pollen
tube
tube cell
nucleus
polar nuclei
egg
degenerating
megaspores
synergids
Embryo sac
(mature female gametophyte)
4. The mature male gametophyte:
A pollen grain that lands on the carpel of the same type
of plant germinates and produces a pollen tube,
which grows within the style until it reaches an ovule
in the ovary. Inside the pollen tube, the generative cell
nucleus divides and produces two nonflagellated
sperm. A fully germinated pollen grain is the mature
The mature female gametophyte:
The ovule now contains the mature female
gametophyte (embryo sac), which typically
consists of eight haploid nuclei embedded in a
mass of cytoplasm. The cytoplasm differentiates
into cells, one of which is an egg and another of
which contains two polar nuclei.
3. The microspores:
Each microspore in a pollen sac undergoes mitosis to become
an immature pollen grain with two cells: the tube cell and the
generative cell. The pollen sacs open, and the pollen grains
are windblown or carried by an animal carrier, usually to other
flowers. This is pollination.
The megaspores:
Inside the ovule of an ovar y , three megaspores disintegrate,
and only the remaining one undergoes mitosis to become a
female gametophyte.
52
Flowers and Diversification

Wind-pollinated flowers are usually not showy

Bird-pollinated flowers are often colorful

Night-blooming flowers attract nocturnal
mammals or insects


Usually white or cream-colored
Fruits of flowers protect and aid in dispersal

Utilize wind, gravity, water, and animals for dispersal
53
Uses of Plants
Plants define and are the producers in most
ecosystems.
 Humans derive most of their sustenance
from three flowering plants: wheat, corn,
and rice
 Simple carbohydrate such as sugar comes
almost exclusively from two plants:
sugarcane and sugar beets
 Our most popular drinks—coffee, tea, and
cola are also from flowering plants

54
Cereal Grains
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grain head
grain head
ear
Wheat plants, Triticum
Corn plants, Zea
Rice plants, Oryza
(Wheat): © Pixtal/age fotostock; (Rice): © Corbis Royalty Free; (Rice grain): © Dex Image/Getty RF; (Cornfield): © Corbis; (Corn ear): © Nigel Cattlin/Photo Researchers, Inc.
55
Uses of Plants
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a. Dwarf fan palms, Chamaerops, for
basket weaving
b. Rubber, Hevea, for auto tires
d. Tulips, Tulipa, for beauty
c. Cotton, Gossypium, for cloth
a: © Heather Angel/Natural Visions; b: © Steven King/Peter Arnold, Inc.; c: © Dale Jackson/Visuals Unlimited; d: © Brand X Pictures/PunchStock
56
Review

Evolutionary History
The Green Algal Ancestor
 Alternation of Generations

Nonvascular Plants
 Vascular Plants

Seedless
 Seed
 Angiosperms

Monocots and Eudicots
 Flowers

57
BIOLOGY
Chapter 23: pp. 408 - 432
10th Edition
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
seed cones
seed cones
pollen cones
a. A northern coniferous forest of evergreen trees
b. Cones of lodgepole pine, Pinus contorta
Sylvia S. Mader
Plant Evolution and
Diversity
c. Fleshy seed cones of juniper, Juniperus
a: © Corbis Royalty Free; b: © Walt Anderson/Visuals Unlimited; c: © The McGraw Hill Companies, Inc./Evelyn Jo Johnson, photographer
PowerPoint® Lecture Slides are prepared by Dr. Isaac Barjis, Biology Instructor
Copyright © The McGraw Hill Companies Inc. Permission required for reproduction or display
58