1. Biology Sylvia S. Mader Michael Windelspecht
Chapter 27
Flowering Plants: Reproduction
Lecture Outline
See separate FlexArt PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes. 1
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1

2. Reproduction in Plants
Biology, 9th ed, Sylvia Mader
Chapter 28
Slide #2
Outline
Reproduction in Plants
27.1 Sexual Reproductive Strategies
27.2 Seed Development
27.3 Fruit Types and Dispersal
27.4 Asexual Reproductive Strategies 2

3. 27.1 Sexual Reproductive Strategies
Biology, 9th ed, Sylvia Mader
Chapter 28
27.1 Sexual Reproductive Strategies
Reproduction in Plants
Plants have a two-stage, alternating life cycle
Sporophyte produces haploid spores by meiosis
Spores divide mitotically to become haploid gametophytes
Gametophytes produce gametes
Gametes fuse to produce a diploid zygote
Zygote divides mitotically to become the diploid sporophyte

4. Sexual Reproduction in Flowering Plants
Biology, 9th ed, Sylvia Mader
Chapter 28
Slide #4
Sexual Reproduction in Flowering Plants
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
anther 2
ovule
ovary
microspore
megaspore 4

5. Sexual Reproduction in Flowering Plants
Biology, 9th ed, Sylvia Mader
Chapter 28
Slide #5
Sexual Reproduction in Flowering Plants
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
anther 7
seed 2
ovule
ovary
zygote 6
FERTILIZATION
MEIOSIS 3
microspore
egg
megaspore
sperm 4 5
mitosis
Male gametophyte
(pollen graIn)
Female gametophyte
(embryo sac) 5

6. Sexual Reproduction in Flowering Plants
Biology, 9th ed, Sylvia Mader
Chapter 28
Slide #6
Sexual Reproduction in Flowering Plants
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 8
mitosis
anther 1 7
sporophyte
seed 2
ovule
zygote
diploid(2n)
ovary 6
FERTILIZATION
MEIOSIS
haploid(n) 3
microspore
egg
megaspore
sperm 4 5
mitosis
Male gametophyte
(pollen graIn)
Female gametophyte
(embryo sac) 6

7. Sexual Reproductive Strategies
Biology, 9th ed, Sylvia Mader
Chapter 28
Sexual Reproductive Strategies
Reproduction in Plants
A flower produces two types of spores
Microspore - Male gametophyte
Undergoes mitosis
Becomes pollen grain
Megaspore - Female gametophyte
Becomes the female gametophyte, an embryo sac within an ovule within an ovary
Ovule becomes a seed
Ovary becomes a fruit

8. Sexual Reproductive Strategies
Biology, 9th ed, Sylvia Mader
Chapter 28
Sexual Reproductive Strategies
Reproduction in Plants
Flowers
Flowering occurs in response to environmental signals such as day length
In monocots, flower parts occur in threes and multiples of three
In eudicots, flower parts occur in fours or fives and multiples of four or five

9. Sexual Reproductive Strategies
Biology, 9th ed, Sylvia Mader
Chapter 28
Sexual Reproductive Strategies
Reproduction in Plants
A typical flower has four whorls of modified leaves attached to a receptacle at the end of a flower stalk called a peduncle
Sepals protect the bud
Petals attract pollinators
Stamens are male portion of flower
Anther - Saclike container
Filament - Slender stalk
Carpel is the female portion of flower
Stigma - Enlarged sticky knob
Style - Slender stalk
Ovary - Enlarged base enclosing ovules

10. Biology, 9th ed, Sylvia Mader
Chapter 28
Anatomy of a Flower
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
stamen
carpel
anther
stigma
filament
style
ovary
petal
ovule
receptacle
sepal
peduncle

11. Monocot vs. Eudicot Flowers
Biology, 9th ed, Sylvia Mader
Monocot vs. Eudicot Flowers
Chapter 28
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. p3 p2
carpel
stamen p4
petal p1 p5
b. Festive azalea, Rhododendron sp.
b: © Pat Pendarvis

12. Life Cycle of Flowering Plants
Biology, 9th ed, Sylvia Mader
Chapter 28
Life Cycle of Flowering Plants
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
anther
ovule
ovary
Sporophyte

13. Life Cycle of Flowering Plants
Biology, 9th ed, Sylvia Mader
Chapter 28
Slide #13
Life Cycle of Flowering Plants
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
anther
Development of the male
gametophyte:
Development of the female
gametophyte:
In pollen sacs of the anther, a
microspore mother cell undergoes
meiosis to produce 4 microspores
each.
In an ovule within an ovary, a
megaspore mother cell
undergoes meiosis to
produce 4 megaspores.
anther
ovule
ovary
Ovule
Pollen sac
ovary
microspore
mother cell
megaspore
mother cell
Sporophyte
MEIOSIS
MEIOSIS
ovule
wall
Microspores
Megaspores
megaspore
3 megaspores
disintegrate
integument
micropyle 13

14. Life Cycle of Flowering Plants
Biology, 9th ed, Sylvia Mader
Chapter 28
Slide #14
Life Cycle of Flowering Plants
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
anther
Development of the male
gametophyte:
Development of the female
gametophyte:
In pollen sacs of the anther, a
microspore mother cell undergoes
meiosis to produce 4 microspores
each
In an ovule within an ovary, a
megaspore mother cell
undergoes meiosis to
produce 4 megaspores
anther
ovule
Pollen sac
ovary
Ovule
ovary
microspore
megaspore
Sporophyte
mother cell
mother cell
MEIOSIS
MEIOSIS
ovule
wall
tube cell
Microspores
generative cell
Megaspores
mitosis
Microspores
develop into male
gametophytes
(pollen grains).
megaspore
Pollen grain
(male gametophyte)
ovule
3 megaspores
disintegrate
wall
One megaspore
becomes the
embryo sac
(female
gametophyte).
integument
antipodals
mitosis
micropyle
polar nuclei
egg cell
synergids
Embryo sac
(mature female gametophyte) 14
(Top): Courtesy Graham Kent; (Bottom): © Ed Reschke

15. Life Cycle of Flowering Plants
Biology, 9th ed, Sylvia Mader
Chapter 28
Slide #15
Life Cycle of Flowering Plants
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
anther
Development of the male
gametophyte:
Development of the female
gametophyte:
In pollen sacs of the anther , a
microspore mother cell undergoes
meiosis to produce 4 microspores
each
In an ovule within an ovary, a
megaspore mother cell
undergoes meiosis to
Produce 4 megaspores.
Mature Seed
seed coat
anther
The ovule
develops into a
seed containing
the embryonic
sporophyte and
endosperm.
mitosis
ovule
Pollen sac
ovary
Ovule
ovary
embryo
endosperm (3n)
microspore
mother cell
megaspore
mother cell
Sporophyte
Seed
diploid (2n)
DOUBLE FERTILIZATION
MEIOSIS
MEIOSIS
haploid (n)
ovule
wall
Pollination
tube cell
Microspores
During double
fertilization, one
sperm from the
Male gametophyte
Will fertilize the
egg; another
Sperm will join with
polar nuclei to
produce the 3n
endosperm.
Development of
the sporophyte:
generative cell
Megaspores
Pollination
occurs;
a pollen grain
germinates and
produces a pollen
Microspores
develop into male
gametophytes
(pollen grains).
mitosis
megaspore
pollen
tube
ovule
Pollen grain
(male gametophyte)
wall
3 megaspores
disintegrate
sperm
antipodals
One megaspore
becomes the
embryo sac
(female
gametophyte).
mitosis
integument
Mature male
gametophyte
polar nuclei
micropyle
polar nuclei
tube
cell
nucleus
egg cell
synergids
egg
sperm
Embryo sac
(mature female gametophyte)
(Top): Courtesy Graham Kent; (Bottom): © Ed Reschke 15

16. Sexual Reproductive Strategies
Biology, 9th ed, Sylvia Mader
Chapter 28
Sexual Reproductive Strategies
Reproduction in Plants
Male Gametophytes
Microspores are produced in anthers
Each anther has four pollen sacs, each with many microspore mother cells
Microspore mother cells undergo meiosis to produce microspores
Microspores undergo mitosis to produce pollen grains

17. Sexual Reproductive Strategies
Biology, 9th ed, Sylvia Mader
Chapter 28
Sexual Reproductive Strategies
Reproduction in Plants
The ovary contains one or more ovules
An ovule has a central mass of parenchyma cells covered by integuments
One parenchyma cell enlarges to become a megaspore mother cell
The megaspore mother cell undergoes meiosis to produce four haploid megaspores, three of which are nonfunctional
The functional megaspore divides mitotically until there are eight nuclei in the female gametophyte
The female gametophyte (embryo sac) contains
One egg cell associated with two synergid cells
One central cell with two polar nuclei
Three antipodal cells

18. Sexual Reproductive Strategies
Biology, 9th ed, Sylvia Mader
Chapter 28
Sexual Reproductive Strategies
Reproduction in Plants
Pollination
The transfer of pollen from an anther to the stigma of a carpel
Self-pollination occurs if the pollen is from the same plant
Cross-pollination occurs if the pollen is from a different plant

19. Sexual Reproductive Strategies
Biology, 9th ed, Sylvia Mader
Chapter 28
Sexual Reproductive Strategies
Reproduction in Plants
Fertilization
When a pollen grain lands on the stigma, it germinates, forming a pollen tube
The pollen tube passes between the stigma and style to reach the micropyle of the ovule
Double fertilization occurs
One sperm nucleus unites with the egg nucleus, producing a 2n zygote
The other sperm nucleus unites with the polar nuclei, forming a 3n endosperm nucleus, which develops into the endosperm
A mature seed contains the embryo, stored food, and the seed coat

20. Plants and Their Pollinators
Biology, 9th ed, Sylvia Mader
Chapter 28
Plants and Their Pollinators
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a. b.
Ba: © Anthony Mercieca/Photo Researchers, Inc.; Bb: © Merlin D. Tuttle/Bat Conservation International;

21. Biology, 9th ed, Sylvia Mader
Chapter 28
27.2 Seed Development
Reproduction in Plants
Development:
Programmed series of stages from a simple to a more complex form
Development of a eudicot embryo
After double fertilization, the zygote divides repeatedly to form a proembryo and a suspensor
During the globular stage, the proembryo is a ball of cells
The outermost cells will become dermal tissue

22. Biology, 9th ed, Sylvia Mader
Chapter 28
Seed Development
Reproduction in Plants
Heart and Torpedo Stages
The embryo is heart shaped when cotyledons appear
The embryo enlarges, elongates, and takes on a torpedo shape

23. Biology, 9th ed, Sylvia Mader
Chapter 28
Seed Development
Reproduction in Plants
Mature Embryo
The epicotyl is the portion between cotyledons contributing to shoot development
The hypocotyl is the portion below that contributes to stem development
The radicle is the embryonic root

24. Development of an Eudicot Embryo
Biology, 9th ed, Sylvia Mader
Chapter 28
Development of an Eudicot Embryo
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Arabidopsis thaliana
endosperm
endosperm nucleus
embryo
suspensor
zygote
basal cell 1
Zygote stage: Double
fertilization results in zygote
(true green) and endosperm. 2
Proembryo stage: Embryo
(green) is multicellular and
the suspensor (purple) is
functional.
zygote
(Proembryo): Courtesy Dr. Chun-Ming Liu; (Torpedo): © Biology Media/Photo Researchers, Inc.; (Mature embryo): © Jack Bostrack/Visuals Unlimited

25. Development of an Eudicot Embryo (continued)
Biology, 9th ed, Sylvia Mader
Chapter 28
Slide #25
Development of an Eudicot Embryo (continued)
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
A. thaliana
A. thaliana
Capsella
Capsella
hypocotyl
(root axis)
epicotyl (shoot
apical meristem)
shoot apical
meristem
bending
cotyledons
endosperm
cotyledons appearing
seed
coat
endosperm
root
apical
meristem
radicle
(root apical
meristem)
cotyledons 3
Globular stage:
Embryo is globe
shaped. 4
Heart stage: Embryo is
heart shaped. 5
Torpedo stage: Embryo is
torpedo shaped; the
cotyledons are obvious. 6
Mature embryo stage: The
epicotyl will be the shoot
system; the hypocotyl will
be the root system.
(Proembryo): Courtesy Dr. Chun-Ming Liu; (Torpedo): © Biology Media/Photo Researchers, Inc.; (Mature embryo): © Jack Bostrack/Visuals Unlimited 25

26. Biology, 9th ed, Sylvia Mader
Chapter 28
Monocot vs. Eudicot
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
seed coat
plumule
pericarp
hypocotyl
endosperm
coleoptile
radicle
cotyledon
embryo
embryo
cotyledon
plumule
radicle
coleorhiza a. b.
a: © Dwight Kuhn; b: Courtesy Ray F. Evert/University of Wisconsin Madison

27. 27.3 Fruit Types and Seed Dispersal
Biology, 9th ed, Sylvia Mader
Chapter 28
27.3 Fruit Types and Seed Dispersal
Reproduction in Plants
A fruit is a mature ovary
Simple Fruits
Simple fruits are derived from single ovary with one or several chambers
Compound fruits develop from several groups of ovaries
Aggregate Fruits
Ovaries are from a single flower one receptacle
Blackberry
Multiple Fruits
Ovaries are from separate flowers clustered together
Pineapple

28. Fruit Types and Seed Dispersal
Biology, 9th ed, Sylvia Mader
Chapter 28
Slide #28
Fruit Types and Seed Dispersal
Reproduction in Plants
Fruit Development
The ovary wall thickens to become the pericarp, which can have three layers
The exocarp forms the outermost skin
The mesocarp is the fleshy tissue between the exocarp and the endocarp
The endocarp is the boundary around the seeds 28

29. Fruit Types and Seed Dispersal
Biology, 9th ed, Sylvia Mader
Chapter 28
Fruit Types and Seed Dispersal
Reproduction in Plants
Fruit Types
In dry fruits, the pericarp is paper, leathery, or woody when the fruit is mature
Dehiscent - the fruit splits open when ripe
Legumes
Indehiscent - the fruit does not split open when ripe
Grains

30. Fruit Types and Seed Dispersal
Biology, 9th ed, Sylvia Mader
Chapter 28
Fruit Types and Seed Dispersal
Reproduction in Plants
Dispersal of Fruits
Many dry fruits are dispersed by wind
Woolly hairs, plumes, wings
Many fruits attract animals and provide them with food
Peaches, cherries, tomatoes

31. Fruit Dispersal by Animals
Biology, 9th ed, Sylvia Mader
Chapter 28
Fruit Dispersal by Animals
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a. b.
a: © Marie Read/Animals Animals/Earth Scenes; b: © Scott Camazine/Photo Researchers, Inc.

32. Fruit Types and Seed Dispersal
Biology, 9th ed, Sylvia Mader
Chapter 28
Fruit Types and Seed Dispersal
Reproduction in Plants
Seed Germination
When seed germination occurs, the embryo resumes growth and metabolic activity
Length of time seeds retain their viability is quite variable
Some seeds do not germinate until they have been through a dormant period
Temperate zones - Cold Weather

33. Fruit Types and Seed Dispersal
Biology, 9th ed, Sylvia Mader
Chapter 28
Fruit Types and Seed Dispersal
Reproduction in Plants
Environmental requirements for seed germination
Availability of oxygen for metabolic needs
Adequate temperature for enzyme activity
Adequate moisture for hydration of cells

34. Eudicot and Monocot Seed Structure and Germination
Biology, 9th ed, Sylvia Mader
Chapter 28
Eudicot and Monocot Seed Structure and Germination
Reproduction in Plants
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
cotyledons
(two)
pericarp
plumule
endosperm
hypocotyl
cotyledon
(one)
radicle
coleoptile
plumule
seed coat
radicle
cotyledon
coleorhiza
Seed structure
Corn kernel
true leaf
first true leaves
(primary leaves)
epicotyl
withered
cotyledons
first leaf
seed
coat
cotyledons
(two)
hypocotyl
coleoptile
prop root
coleoptile
radicle
hypocotyl
secondary
root
adventitious
root
primary root
primary
root
primary
root
coleorhiza
Bean germination and growth
Corn germination and growth a.
a: © Ed Reschke; b: © James Mauseth b.